How to determine the source of engine knocking noise

This video shows how to determine which cylinder is knocking. I isolated the cylinder and also checked if it was the valve lifter. The last part shows the bad rod bearing on an engine stand.

[@harlanbutler2321]

thank you for posting this video!! as a girl who works on my own car, i find it interesting to see an engine run. i know my limits and i don't mess with the engine because I don't know enough!

[@harlanbutler2321]

Well that was well said! My dad taught me to work on cars, which most men find hard to believe. I have taken engines apart but had a mechanic put back together. It was not my car and I was trying to save an elderly woman some money. The mechanic was amazed I did such an organized job.

[@felecitabischoff5818]

Great mechanic information learned a few things about my vehicles today

[@wandov8]

Nice video, thank you. Hugs from Brazil.

[@davidlis6709]

Thanks - I live near San Francisco, Ca

[@ralphvalkenhoff2887]

Good video. Nice work on editing. Makes me want to see more. Tip, would have liked to see pulling the motor.

[@davidlis6709]

kzbin.info/www/bejne/fpnJnYtudpiCj68 Here is the install. I have a removal but I can not find it. Maybe Google deleted it.

[@ezequielm8975]

Thank you for the video very helpful

[@davidlis6709]

Happy it helped

[@Em6726]

Thank you for the informative video. Now I know what is wrong with my Ford 240 big six.

[@jimbola77]

very great explanation!!!

[@ghostduckinvestigations9798]

excellent video man!

[@davidlis6709]

I wish the voice was a little louder.

[@Cutsbywesley]

Thanks. Great video!

[@davidlis6709]

Hope it helped you.

[@MariaGonzalez-ei1pv]

Great video, you tham goood..well explain

[@davidlis6709]

Thanks, just trying to help as many people as possible.

[@jakewhitney1230]

Awesome video. did you make one about the repair or any further than what's in the video? It just stops (the video) with the engine still open

[@davidlis6709]

I don't know what you mean. I made several on a Chevy 350-V8. Taking it apart and putting it back together.

[@celestahouk658]

need help for my 2005 tribute 2.3 motor replaced with a 2.3 2006 all is well but. a loud tapping and cutting back after 50 mph

[@burnzy7722]

I could tell it wasn't valve related right away. You won't hear such a deep "knock" from valves.. Value issues sound more like a "tick" or an exhaust leak...

[@davidlis6709]

Did you find the cylinder that had the problem

[@RohanSanjith]

@@davidlis6709 no

[@davidlis6709]

@@RohanSanjith Do you try letting the engine run with 2 spark plugs off so when you take the third one off it really makes a difference.

[@bentroche6568]

Thank you sir for the video

[@davidlis6709]

Hope it helped

[@modeljetjuggernaut4864]

Great video sir

[@davidlis6709]

Thanks

[@nyplantingsgardendesigners5645]

But mine is an LS7 put together like crap by "injection connection" in PA. I dont want to take my motor out and find a bad bearing! I dont wanna take my motor out! Damned if I will ever let anyone work on my car again though. We are in trouble here in the USA the quality and pride is gone with the last generation. Thanks for the video. Keep on for the real engine guys!

[@davidlis6709]

You are right. That old world craftmanship is hard to find. Sorry to hear you are having an issue. Pulling out the engine is a lot or work and the worst part is that it is summer when you want to drive the car. I make theses video to give confidence to the regular guy. Go for it, what it the worst that can happen.

[@azrailfan2717]

Very helpful video. I wonder if the same technique can be applied to a ford 250 Inline 6. It developed a knock recently and I’m trying to research about how to fix it

[@davidlis6709]

Yes, just take off a plug wire that has spark that makes the engine skip, when check the rest of the cylinders.

[@mabast007]

Torque specs?

[@Hot80s]

Great vid.

[@davidlis6709]

Thanks, I hope it helped you

[@cth0211]

remeber to use some type of oil supliment in older flat tappet motors, most oil has reduced anti friction additives as all engines built now have roller lifter or roller tappets. I use diesel oil(rotella 10/30 or 15/40) it still has the needed additives required in flat tappet motors. GM sell EOS engine oil suppliment for this reason.

[@jayryan7473]

Thanks for the advice Tim. A few years ago my 350 had a lifter go bad. I ignored the noise and eventually I had to replace it with a different engine. That 305 for some reason had similar horsepower and I was happy with it... until that engine had a lifter go bad. I replaced the lifter immediately. Surprisingly a simple but time-consuming project. I've been wondering why people are using Rotella diesel oil, now I know.

[@b.c.cooper9559]

The problem is also finding the right person to do the job no one is returning my calls as when they want to start the jobs 5k are just estimates, I 100% agree with you, thanks for your help.

[@davidlis6709]

Where do you live? Are there any old car clubs around? Go to some of the old cars shows and ask all those people, you may find someone that works at a garage that will do it on the side.

[@b.c.cooper9559]

David Lis I live in Tacoma Washington, that's a good idea, will do, always loved this car but never knew it would be such a pain.

[@davidlis6709]

Anything that is worth it or you really like can be a pain but once all the problems are over, you will love. If I remember correctly, that car has electric windows. I love driving my 70 Chevelle but never in the rain. I am afraid of other drivers so that limits your driving days. The only thing I could not do to my car is paint it. Not because I cannot because in my 20's I painted many a car. I live in Santa Clara county (Silicon Valley) and they only allow water base paint and they do not sell paint to people who do not run an auto body shop. So, I went to some of the local car shows and talked to everyone that had a nice paint job on their car. Everyone was happy to talk to me and told me who painted their car and how much they paid. I then contacted several of them and went to their homes with my car and got estimates. I already knew their skill level by looking at the cars they painted. I finally found this guy who did it at home and in Santa Cruz County that still allows oil base paint. It came out super. One of my video shows him painting the car. I was lucky because he allowed me to go into the paint booth with him and video him painting the car. Be patient, you will find someone. Summer is coming, meaning a lot of car show.

[@b.c.cooper9559]

Power windows, seat and steering _lh3.googleusercontent.com/QJqY1LDQLQZ0kO6O6LwYbao0hYek_a13ZjJCg6kRdvbHrhvyHsBsbO26-MNf7jmDS2ekaqDWcg_

[@davidlis6709]

404. That’s an error.The requested URL was not found on this server. That’s all we know. It does not like something.

[@jerryrichter4904]

hey dave when you rebuilt that engine did you put any kind of sealer on the head bolts i seen the video about oil pooling on intake

[@davidlis6709]

No, just a tiny bit of oil on the threads

[@macittluke]

had the same problem in a ford minivan. .but the mechanic said he replaced the bearings but still the knock without taking the engine out..my suspicion is that he never did what he said so.....

[@These-nutz]

You have to floor it to 8k rpms to really hear it

[@tomseklawi6766]

Thank you

[@fisikitoful]

you are so clever ! my car sounds like that and i know now what happend. Thank you!

[@SGTMillerm]

i work as a offroad tech and specialize in engine diagnosis. your passenger bank rockers should be shooting out oil from push rod holes. a good lubricated enginr with 30psi oil. will pump out a small stream. they are oozing out. make sure metal shavings didn't get clogged in cam bearing in back. it takes one shaving. blow air into each push rod

[@davidlis6709]

The block was washed in a hot water tank. I soaked the push rods in gas and blew air through them. Oil does come by not as much as you expected. I have about 4,000 miles on the car and it runs great.

[@SGTMillerm]

David Lis mhmmm did you remove the cam bearings in the back? it should be a squirt per say. 3 inch squirt. how's your pressure at start up? is it really high? Like 65 80psi? only reason i say this. if i had a nickel. for every build we've done or head rebuild. when it's oozing like this. 99% of time. it's coming back. might be 10k miles or 3k miles. but at very high rpms. (we put a recording scope under cover) like 4k and up. it's vibrating so fast that it blows the oozing oil off rocker before it gets to valve. its most likely fine and most likely never cause you an issue. i just thought id help and stop the headache I've had with that. what mine usually ends up being is 3 things. bearing oil hole off center. rtv from oil pan or convert 2 gasket gets squashed into oil then finds its way into a oiler hole or valley. or one lifter in way back is stopping the flow somehow. i can count 4 times where I've said to myself. i should fix it. but it's always. customer is wanting it back this afternoon. so i shoot air put Trans fluid down push rod holes. cover it up. fire it up hold at 1600 rpms. sorry to get into it. and hope i didn't insult you. ones i build are for rock crawling. or mud hogging. so they run high rpms or high torque low rpms. but you'd be amazed how a tiny sliver of metal holds back 60 psi

[@Realofficialdee]

@@SGTMillerm what you think about mine ? Came after an oil change. I also was running 87 in my charger hemi kzbin.infoRJ-u8Sy13-Q?feature=share

[@edwardwilson7538]

Is 60-65 psi good at cold start? Then drops to 35-40 psi after warmed up?

[@b.c.cooper9559]

Hey david what kind of oil you would recommend to run in my 62 continental 430 engine , I was told I should use straight 30 weight.

[@davidlis6709]

In the 1970s/80s, I used straight 30 in all my cars. I was told to use what the manufacturer recommends because that is what it was designed for. That being said..... I was told in about 2012, I should use 5- 30 because oil is made different now and using the lighter end of the oil (5) is better on start up because it gets oil to the bearing faster and the lighter blend adds less friction to the engine when running. I have never heard anyone say that their engine stopped running because of the weight of the oil they used. You can only find out if you use a oil weight and take the engine apart and look at the bearings, then use a different weight for a while and do it again. In my 70 Chevelle, 90 Mercedes 420SEL, E150 Ford van, and 2012 Toyota Camry, I use 5-30 or 10-30, whatever is on sale. I really don't have preference for the brand, they are all made to a certain standard. I know I probably be blasted for making such a comment but that is what I believe. 70 Chevelle - 3,500 miles on new engine (change every 3,000 miles), Mercedes - 220,000 miles (change every 5,000 miles), Ford van 55,000 miles (change every 7,500 miles - recommended by Ford), Toyota 75,000 (change every 5,000 miles), and old Toyota sold after 285,000 (change every 5,000 miles). This is another big no - no. Also, the 2012 Toyota, I changed from synthetic to regular. Instead of changing oil at 10,000, I do it at 5,000. There are several articles on the internet about the differences. I talked to the Toyota dealer and he said that when these cars get older and use more oil, the people that change their oil at 10,000 to 12,000 might run out of luck and run their cars out of oil because they are waiting for the 10,000 marker versus me changing it at 5,000. I will notice it because I do it at sooner increments. I have hears some stories of people running their cars out of oil because a lot of people these days don't maintain their cars and never think to check the oil level never mind ever change it. There is the old saying: pay me now or pay me later. All this is a matter of choice. I understand if you are racing the hell out of that engine but you are going to be on old fart driver cruising down the highway with the radio going, rolling the electric windows up and down with the air conditioning on, just loving life driving your big old Lincoln Continental. Do you ever listen to public radio at about 10 or 11 am on Saturday and maybe Sunday, the Clicket and Clacket brothers? (Different times for different parts of the country). Or maybe it is call Car Talk, they talk about car and car repairs.

[@74nova36]

Excellent. I run a Rotella straight 30 in my ‘74 250 inline 6, with zinc added after the fact.

[@MrTarkus007]

great video you should of had a second part it seems to cut off at the most interesting part if you have a second part please tell me where . very interesting vid..

[@davidlis6709]

The next part is to take the engine apart and replace the crankshaft, etc.

[@senseirandy9491]

Cool test. Just wondering if you noticed that you pulled the same spark plug twice on the 3rd and 4th pull... Though that is a cool test I never thought of doing.

[@davidlis6709]

I guess I missed it on the video but I did it a few times before I made this video. I have done this same operation on many other cars and it works. You can see in this video when I took the engine apart, two bearings were scored, which makes the knocking noise.

[@veronicagorosito187]

@@davidlis6709 Hey this is a really smart test! I have a nissan datsun 200L, could I test it this way without making a bad mistake or damage? Thank you!

[@davidlis6709]

@@veronicagorosito187 Yes, all you are doing is disconnecting spark plug wires when it is running. Take off the wires before doing the test so they come off easy and use pliers that have a plastic coating so you do not get shocked. If you do, it is not that bad.

[@mikeroman2692]

NICE VIDEO

[@davidlis6709]

Hope it helps

[@b.c.cooper9559]

yeah I do listen to station, just got the car back out of the shop it keeps stalling, so they replace the fuel pump and they said that should resolve my problems but i still have that knock in the valvetrain so that's my next project and also rebuild my front end suspension.

[@davidlis6709]

I have a video on rebuilding the front suspension just in case you want to get crazy

[@DIABLO_4_Tester_Sacramento]

Did you install the standard size rod bearings with the sound you had on this video ?

[@davidlis6709]

No, the crankshaft was damaged beyond repair. I purchased an entire engine rebuild kit and it came with a new crankshaft and matching bearings. I had the block bored out .020. The kit came with pistons and rings. I wanted a new engine because I knew I was going to keep this car for a long time.

[@tpcoachfix]

Valve noise would not stop by just pulling off the spark plug wire. You have a problem with the rod bearing.

[@120hp660raptor]

best remedy for this is to enter it in a burn out comp after about 5 minutes you will be able to get a real good look at that rod without even doing a tear down.

[@lynnchelo4727]

tpcoachfix piston slap on Chebys

[@lost94133]

just turn up the radio problem solved

[@davidlis6709]

This one was a little to loud. It was not going to last long if I kept driving it.

[@fury3600]

worked once for me, rear wheel ripped off and brake rotor melted in a 04 merc mountaineer, was just driving down the road to pickup a pack of cigrits

[@blake1995]

Maybe if you didn’t buy cigarettes you’d have money to fix the car at the time

[@snowflakesnuffer9334]

@@fury3600 maybe if you didn't replace vehicle noise with music, and just fix the problem... you would spend way less $ on further problems caused by not taking care of the first one..

[@Oldsmobilef85]

@@blake1995 alot of truth to that

[@jasonnitz548]

Great video! I have the same issue with my 383 Stroker (67' C10) was getting mixed reviews from friends/those more knowledgable than me as to whether I had an exhaust leak or loose lifter. About to try your distributer trick now to narrow it down. I'm assuming the knocking did not go away after you adjusted it, hence you pulling the engine. I'm really hoping I don't have to go that route! Fingers crossed.

[@davidlis6709]

My engine had 125,000 miles on it so it was wore out. Runs great now but it was a lot of work. It took me weeks of working on it part time.

[@jasonnitz548]

Sounds like it. I ended up having incredibly loose exhaust header bolts on the aft end of the engine. Replaced gaskets/bolts on both sides. Sounds much better now. I still don't understand why when I was troubleshooting, disconnecting the #2 plug from my distributor made the sound went away..no spark no combustion to move the lifter?

[@davidlis6709]

Another way to check is to get a long screwdriver and put one end on your ear and then put the other end on the engine. Then you have to probe around from cylinder to cylinder and you will be able to hear the loud one.

[@michaelharrison4068]

jason n

[@emozburnes1733]

I have the same problem I with my 350 same sound I hope it is fixable without having to tear motor down

[@willadams160]

Hi I am having a similar problem with my 2011 5.0 mustang. Slapping/ticking noise and some bad power lag. You think it could be a sticking lifter? The power lag threw a camshaft position sensor code too. Also do you think I can disconnect the electrical connector to my ignition coils and do what you did here? I don't have plug wires you see just 8 coils with connectors on each plug.

[@davidlis6709]

Sorry, I don't work on the new cars. You can try disconnecting each ignition coil and see what happens. You might have to disconnect one and leave it off then rotate to the other ones, meaning it will be running on 7 cylinders so it will make a significant difference. There is another old trick and that is to get a long screwdriver and put the handle end on your ear and put the tip on the intake manifold and move it to different positions to see if you can hear what cylinder the ticking noise is coming from. If you find where the ticking is coming from, take the coil off and listen if the noise went away and it should come back when you reconnect the coil.

[@willadams160]

+David Lis thanks for the info. I have a feeling of where the dodgy lifter because I did that pipe trick and listened and it's also coming from where the slightly oily spark plug is. I'm going to get the rocker covers off and have a closer inspection should be easier to tell then will probably see straight away which lifter/rocker is knackered!

[@davidlis6709]

With all the high tech tools available, and here we are using a pipe or a screw driver to find where the noise is coming from.

[@Querencias7]

Ha! The pros and cons of old school, low (very low) technology!

[@JoeVizethum]

like your video - very helpful. On my XJ 4.0 injection engine I have a knocking noise and will be doing the same procedure. You better disconnect the spark plug wire at the distributor cap, not at the spark plug, right ? Would you be damaging the coil ? Thanks !

[@davidlis6709]

It is just easier at the distributor cap. And it does not damage anything. Unplug the each wire from the cap and put it back only part way so it is easier to unplug and plug the wire back in the cap while checking all the cylinders.

[@JoeVizethum]

@@davidlis6709 great - thanks, bro !

[@davidlis6709]

@@JoeVizethum What did you find out?

[@JoeVizethum]

@@davidlis6709 thanks for asking - well, not quite clear still - did unplug cylinder 3-6 and the knocking gets quieter/barely noticeable specifically when I unplug no. 6. As oil pressure is perfect (50/60 cold, 30 hot) and no visible abrasive wear in the oil/oil filter I guess it's piston slap and not connecting rod bearing - which is the minor culprit. Also checked up flexplate ok. Can I send you a video to recheck as an expert ? Thanks !

[@mikesaltman]

I’m having knocking problem with my 97 Ranger 2.3 but the knocking gets loud on acceleration and kind of goes away at idle or deceleration, it missing like a plug wire went bad and has a serious loss of power. I recently replaced the timing belt so I’m going to check the timing. I’ve had a code for the EVAP solenoid for two years because someone did away with it completely, also have o2 sensors upstream and downstream of catalytic converter. Any advice?

[@davidlis6709]

I had the same issue with the engine you are looking at in this video. When I stepped on the gas the knocking sound got louder and when I let off on the gas or drove around easily the sound was a lot less. I did not have a power loss. How many miles on the the Ranger? If it has a lot, it could be rod bearing but I am not there to listen to it.

[@keithhawkins653]

great video going to try this on my 72 oldsmobile cutlass ticking sound is driving me nuts. seems to be no exaust leak thinking it's a lifter.

[@davidlis6709]

+Keith Hawkins It is probably not a knocking noise, just loose valve lifters. Take one valve cover off and use a large screw drive, the plastic side goes on your ear and the tip goes on the rocker arm. Go to all of them and hear which ones are making noise. Them tighten the noise ones a 1/4 turn and see if that quiets them down. Be careful not to tighten to much because it could screw up your valve. If the motor starts to run rough, it is to much. Let me know.

[@keithhawkins653]

+David Lis have the cover pulled now am going to try tightening it up I know which one is ticking from pulling wires off the distributor but they all seem fine at first glance

[@keithhawkins653]

+David Lis uploading a video now not running but I will post one after with it running any help would be hugely appreciated

[@mikelbrooks1900]

I have 04 grand prix gt, knocking...rod barrings were changed but still knocks. Could it be the lifters. Mikel in Ks

[@davidlis6709]

Does the car knock in idle? An old way to check is to get a long screwdriver and put one end on your ear and then put the other end on the engine. Then you have to probe around from cylinder to cylinder and you will be able to hear the loud one.

[@74nova36]

Even though I know how to do this, it’s still refreshing to see it done In actuality. Sometimes it’s easy to forget exactly what’s going on in an engine at every given moment. What do you think caused it to be spun. Low oil? Or was that the original motor unopened?

[@davidlis6709]

I don't know. When I got the car it had 125,000 miles on it and sat in a storage container for 22 years. It needed everything. It took me 4 years to take the car completely apart and put it back together again. Now, I just enjoy and drive the car. It has a few dings from stupid brain dead people. I try to park it by itself but when I return, they are always cars on both sides. That is not going to stop me from using the car as much as I can.

[@74nova36]

@@davidlis6709 that’s how I feel, I don’t even have a door ding yet and only some rust under the paint on the door window rain rails. I want to drive it everywhere, had to redo the electric ignition as I burned the igniter module by leaving the key in Acc for hours. I don’t like my current choke set up as it’s routed from exhaust air until it warms to temp.

[@74nova36]

@@davidlis6709 glad you got her running!

[@AnthonyHernandez-lr5uu]

Like they say, "if I can reach one person, I'll feel like I made my contribution to my fellow man" With that being said, I had to adjust my rocker arms/valves, but I remember that it was a mess even with the cardboard dam. So that night, I thought and thought, of what could I do, to eliminate having to use the cardboard dam. Then it came to me, I went to the junkyard and found two exact valve covers, you just really need one(flip it around), but go ahead and bring the other one of you want. Cut you a window, just enough to see and adjust your rocker arms. I used my Ryobi reciprocating saw, please, please be careful though!! and cut the window. I took off the original cover and put the one I made on, and adjusted the rocker arms. No fuss, no mess. Just in case, I had a towel underneath the cylinder head and above the exhaust. Hope this helps you all?? Take care, and God bless!!

[@davidlis6709]

I like it. The cardboard dams do not stop all the oil for gong on the engine.

[@AnthonyHernandez-lr5uu]

Yes David, but Thank you so much for helping all of us, with your video and your instructions as well! It helped me tremendously. Oh, wanted to share something with you, and the rest of the gang of which you all may already know. The other day, my '93 GMC Sierra 1500 V6 just died, as I was turning the corner, no warning, no nothing! I scratched my head, it would turn over, but wouldn't start. I should've remember what Dad used to say, check two things, oil and fuel. my bro-in-law checked the fuel pump opened the gas cap, could near it clicking, then he said, I know exactly what it is! y0our ignition control module, under the distributor cap, he had an extra one. Yay! that was it! Wanted to share. I guess I could've pulled one of the spark plug wires?? You all tell me please?? but then again, when you're alone, can turn the key.... take care!!

[@gamingforhumanity6659]

Doing too much

[@letsthinkitover1]

Arizona here if we find the one that's knocking can we take plug wire off and drive it . valve lifter? ?

[@davidlis6709]

You can always drive it but you know something is wrong.

[@juiceslickrick]

I have the exact same sound but when I pull each wire the sound is still there. Sometime the sound comes and goes and is very loud at times. What could this mean ?

[@davidlis6709]

Take one off and if the noise does not stop, keep that one off because you know that is ok. Then take another one off, this way 2 cylinders are not firing and it should put a larger strain on the engine and be more noticeable.

[@juiceslickrick]

David Lis Thank you . I’ll give it a try

[@mariosgbodys]

i have a similar kind of sound! But when i tighten the rocker, it makes it more silent or sometimes it makes the knocking go away. But after a couple seconds, the sound comes back . Does that mean i have a bad lifter or bad barings? Btw: The sound goes away when i accelerate.

[@mariosgbodys]

Video on my channel

[@davidlis6709]

I believe you have a bad lifter. Don't tighten it to much because it will cause the valve to stay open and the engine will run rough. How many miles on the engine?

[@davidlis6709]

It seems that you have a bad lifter. Be careful about tightening the lifter to much because if you tighten it to much it will not let the valve completed close and the engine will start running ruff. Try - let the lifter knock and try the removing the spark plugs and see it you can get it to stop. If it does not stop, then it can not be the rod bearing.

[@joshwebber98]

Hell of a cutscene

[@r.d.ontheroad-1094]

This is confusing, is it the same engine, did you rectiify the lifter noise, or was it a bad rod bearing.

[@davidlis6709]

Yes it it the same engine. I removed it from the car and removed the rod bearing shown at the 6:00 minute mark on the video.

[@Jiropo05]

ggarcia- we have the same problem . if ever you found the solution can you shere it with me . thank you

[@lesliebalasan2582]

sir.ask what couse in the push Rod bent

[@davidlis6709]

Maybe your hydraulic lifter got full of slug and didn't compress correctly (far enough) causing to much pressure on the push rod and it bent. The cam comes up and the valve can only go down so far, so the lifter and the push rod are in the middle.

[@randymogstad]

Overtightening them cause they are hydrolic

[@celestahouk658]

had a motor replaced in a Mazda tribute now this motor has a loud tapping and cuts back after reaching 50 mph replaced fuel pump all air sensor and erg is fine any suggestions it has been 7 weeks no way to go

[@davidlis6709]

Sorry, I am not familiar with those cars

[@frankguerra3314]

Can u do that on all cars an trucks.i had put a 360 in my dodge 1500 an I hear knocking.dont know if it's the damper or rodes.

[@davidlis6709]

Yes, do it on any engine. If the engine has been sitting for a while or has high mileage, it may be the valve lifters. Old school, take a larger screw driver, put the plastic handle on your ear and with the metal end, start putting on the valve cover by each cylinders and see if you can tell the difference in the sound from different parts of the engine. You might be able to locate the noise. You can also do it on the oil pan.

[@sr2Xvet]

Just curious I have an old 350 with spun bearing an I polish the crank and seems ok.. can I put std bearings in an get more mile out of it? Has 270k miles if I get 5-10k more miles I’ll call it a win.

[@davidlis6709]

But it may be out of round. Since you polished the journal, it reduced in size. You have to measure it and buy a bearing that matches the journal size. A machine shop would probably be your best chance of just buying one bearing set. It is a lot of time and money to get 10k more miles out of it. Why not just rebuild the entire engine?

[@stanleyphiri8802]

my Mitsubishi IO 98 just changed rings and new valve seals . but cant start its backfiring now. help how do i sort this out. help

[@davidlis6709]

Backfiring has nothing to do with new rings and valve seals. I believe that is a timing issue. Did you pull the distributor? If you did, I think you might have put it back in and now you are one tooth off. Meaning the timing is to far retarded and advanced.

[@genxmurse7019]

Can the crank be resurfaced or does it have to be replaced?

[@davidlis6709]

Just replace it and get new bearings.

[@kdogs8715]

If it’s scarred you will have to remove have it turned or buy match crank and bearings scaring will eat lead off bearings be back same

[@sofienesaaden2350]

Bonjour j ai un Volvo penta 5.7osi j avait un problème l essence ce mélanger avec l huile j ai régler le problème mais depuis que j ai régler ce problème la pression d huile quand je tourne le moteur à 4500 rpm descend au milieu et de temp en temp j entend un les culbuteur et au ralenti rechute un petit peut mais pas dans la zone rouge j utilise de l huile 15w40 svp aider moi please help me

[@tirthjoshi9731]

i am having the same problem can you please answer if i can drive with this for few days as in for 5 days more as i have to go out of station and need this car, is it risky to take it out on road with this condition is there a chance of break down?

[@davidlis6709]

I cannot give you an answer but I will tell you what I did. I drove my car with it knocking knowing that I was going to take it apart. But I notice that when the motor was straining, like on take offs it was louder. So I drove my car but I also only drove it in the city and not on the highway going fast. Treat it with kid gloves and it might be good for 5 more days.

[@davidlis6709]

What happened?

[@jeremyrowe4339]

My mercruiser is making a knocking sound but it is pushing air through the carburetor. Could this be a valve or maybe rings?

[@davidlis6709]

Valve. Do a compression test and it will tell which valve is not working. The local auto parts store will rent you the tools for free.

[@bigman7293]

My 2.2L S10 with a pushrod engine makes a very similar knocking sound but it's not as loud... i just got a new head on it since the old one warped from running in too low a gear uphill on the highway and it's still knocking only when it's cold. A spun bearing makes sense but I would have to pull the motor like this one

[@davidlis6709]

Maybe you can lift up the motor up enough to take off the oil pan. You will have to disconnect the motor mounts first and when lifting it up be careful not to let the fan hit the radiator. If you can get that far, remove the oil pan and remove the rod bearing that you think is knocking. I did this in high school but it was a very hard way to do it. If it is good, put it back on and torque it down. If one of the rods are scored, you will have to pull the motor. Put the car on jacks, get under it with it running and take a long screw driver and put one end on you ear and put the other end on different parts of the block and oil pan (front to back), and see if you hear the noise from the bottom.

[@bigman7293]

David Lis that third part is a very good tip, thanks. But if I were to do that I would pull the motor out all the way. No point in leaving it in half way and making it a huge pain in the ass. The whole reason I have to lift it out is because there's a crossmember right under the oil pan and it's probably important

[@davidlis6709]

You are basically stuck.

[@stayhumblehustlehard.8014]

I have a 2003 Buick lesabre 3800 v6 Series 2.. are there any videos out there to address how to easily fix a knocking or tapping noise in this type of engine. please help. thanks.

[@davidlis6709]

+Donnie Bolton Sorry, I have no idea.

[@thomaswilding8818]

For anyone landing here, I did a video on the 3800. look up youtube video MhwpmFS2Z3k

[@dirtbikekid]

Out of curiosity, why does the noise go away without spark if the bearing is still rolling around? Without the combustion happening in that cylinder, the bearing is able to keep from spinning?

[@dirtbikekid]

+Mitch Hill Great video by the way.

[@davidlis6709]

+Mitch Hill With the spark plug wire off, the cylinder does not fire, so it does not generate the force of pushing the piston down, there is no pressure on the bearing. So the bearing is just going around the crankshaft with the help of the other pistons doing all the work. It is still not going it any good because the bearing is just scraping the journal on the crankshaft as it goes around. It is only a matter of time before the connecting rod brakes and does real damage to the engine block. Then you have real problems, like maybe needing a new block. Once the bearing starts spinning on the crankshaft, it will always spin because the tabs the hold it in place are gone, I show it at the 7 minute mark in the video. My was so bad that I had to buy a new crankshaft.

[@dirtbikekid]

+David Lis Understood. Thanks for the reply.

[@jeremyrock7446]

Mitch Hill because the piston has no load on it when it’s not firing

[@superwhuffo1]

I was going to buy a 502 f150 1990 truck..but it was knocking.. and it seemed to be coming from the bottom end..you just kept me from buying this truck. Thanks!

[@davidlis6709]

You are welcome. What a nightmare that would have been.

[@davidducatie4357]

hi i have a nissan maxima and it makes the similar noise it runs great but does shake somtimes and leaks oil. could it be the timing chain or vavles idk pls help

[@davidlis6709]

My car ran good but made a knocking noise because two of the rod bearing were spinning and it was just a matter of time before the rod would detach from the crank and really damage the motor. Leaking oil does not have anything to do with the knocking. It would not run if the timing chain jumped a tooth. If the valves were bad, the car would not run good. Did you pull the spark plugs and check?

[@davidlis6709]

My car made the knocking noise and ran good except if I kept on driving it one of the rods would detach from the crankshaft and do more damage to the engine. The oil leak would not effect the running or knocking. If the timing chain jumped a tooth, the car would not run good or maybe not at all. If the valves were burnt, it would not run good. Did you check by taking off the spark plugs and hear the noise go way.;

[@backyardbuilttrucks1]

A oblonged valve guide can sound like a lifter tick with the valve moving side to side in guide.

[@davidlis6709]

But the noise will still be there if you disconnect the spark plug.

[@backyardbuilttrucks1]

@@davidlis6709 Not always

[@papergatorzfedducca7998]

Will this work on a 2010 Camaro LT V6 3.6?

[@davidlis6709]

Yes, works on all engines. Just remove 1 spark plug wire at a time. Also, pick one and remove it then go to each one. Removing one will put more of a strain on the rest of them, it should be a little louder.

[@ggarcia713]

I have a question...I have a knocking noise in my engine, but the knocking noise happens after the fact i have taking off and i finally stop at a red light thats when i hear it?

[@MrNotorius5500]

Either you have loose flexplate/flywheel bolts or you have a bad main bearing.

[@davidlis6709]

Did you go through this process? Before I checked it out, it would only do it when I was accelerating under power. I think I put on 200 miles before I realized something was wrong. Maybe it is the valve lifters? Just try the spark plugs first.

[@sandywillmott5940]

David Lis )7

[@jasonism123]

I have the exact same knocking sound on my corolla..so could it be just the head, or does it need a general overhaul?

[@davidlis6709]

+Paul Jason Did you pull off the spark plug wires one by one to see if the noise went away? How many miles on the car and what year is the car?

[@jasonism123]

Yeah, I haven't tried that..I'll try it today, and get back to you..it's got 133,000+ kilometers. I did some research..they said it could be a lifter or push rod problem..worse is a piston slap..but I don't get smoke/blue smoke on my exhaust..and the engine power seems ok.

[@davidlis6709]

Have you pulled off the valve covers and looked to see if the rocker arms are all working or the push rods are bent? Do one side at a time and like in my video, use a piece of card board to keep in the oil. If they look ok, take a large screw driver and carefully put it on the bolt of the rocker arm and put the plastic handle end on your ear. Go to all of them and see if your can hear the bad rocker arm/lifter/push rod.

[@jasonism123]

David Lis Okay, I'll try that. I did the spark plug wire test. I think it's cylinder no.3. I also went to a shop today and had a compression test(wet/dry), and it also turned out fine. They still can't figure out what caused the knocking. They were talking about a top overhaul, I said No, not yet. I posted a video on the compression test I had this morning. You can check it out.

[@davidlis6709]

Where is it?

[@b.c.cooper9559]

I also have a ticking/knocking sound coming from 62 continental I was told I need to rebuild my motor, also the the vehicle dies or wouldn't start when it get hot it has to cool down before it restarts I've replaced points, plug, adjust timing it a tune up and still having that problem.

[@davidlis6709]

Did you do a compression test? You can rent a compression tester from your local auto parts store. My book goes back to 1963 V8-430 engine and it should have 180 pounds of compression +/- 20 pounds. When you took out the spark plugs did they have oil deposits on them, were they black? How many miles on the car? Remember, those older engines were made to run about 100,000 miles. Is this the original engine, is the car all original? What shape is the car in? Do you have plans on keeping this car? How much did they tell you it would cost to rebuild the engine?

[@b.c.cooper9559]

the compression test was good its all original motor it has 99k on it, I paid a shop to do the tune up to my knowledge their hasn't been any work done on the motor its other a new water pump.

[@b.c.cooper9559]

I was told it could cost up $5k to rebuild it, I bought the car over a month know pretty anytime I drive it someone wants to buy it so i think its in good shape other the knocking and stalling.

[@davidlis6709]

$5k sounds reasonable because they have to take the motor out of the car and the parts are more expensive than your standard 350 Chevy V8. I think your motor is just tired and wore out. If you do decide to rebuild it, buy a new starter and alternator, those will be going next. Install them at the same time so you don't have to do it separately. Then you will have a dependable car you can drive forever.

[@55dpc]

My 292 6 cyl has 7,000 miles. A little knocking noise at stops. It's a 75' long block and noise is an issue. A very simple machine! Any advice?

[@cth0211]

David Chambers those older engines really need a good diesel oil(rotella 15/40 in summer,10/30 in winter) all of the new oils(including synthetics)have reduced or no anti-friction additives. the diesel rated oils have the additives needed for the metal to metal contact the lifters make. it is a better grade of lubricant. my 88' 5.0 mustang had 155,000 miles when I tore it apart rebuild it for racing duty. it had virtually no wear in the bores and bearings. it had no ridge at the top of the cylinder bore . I used 15/40 oil in it always. I drove that car hard. that block is in my 90 coupe now still with standard bore, standard rod and main sized bearings! I put all new bearings and rings in it anyway

[@SS4LiFe1488]

Take a hose and cut maybe 3 feel off it, turn the engine on and listen for the tick, once you hear the ticking take the hose and slowly move it around the engine until the ticking gets louder and louder. That will determine whether the tick is at the heads or down by the cam shaft. Hope its the top end.

[@MrTarkus007]

i have the same knocking noise when driving my truck (350) &when i push the gas it's been doing that for a while (years) also little blue smoke when i start it (piston ring i presume )

[@davidlis6709]

Blue smoke means the piston rings are getting tired.

[@MrTarkus007]

is that a very expensive job? &2nd what can be done with the knocking ?

[@MalindoWe]

not an expert but it seems like you will pull out the bottom part of the engine to asses the damage caused by knocking, inspect for defects on crankshaft and the rod. Pull the entire engine out and do the seals to save time plus labor

[@wickidflash]

Spark plug removal confirms its reciprocal and isolates the cylinder. Valve adjusting was a waste of time. Plus, the notches in the bearing don’t hold the bearing in place. It’s the torque on the rod caps and the crush of the bearing.

[@davidlis6709]

Then why did the motor last 125,000 miles? Did the torque decease with mileage?

[@wickidflash]

If a crank journal chirps against the bearing enough, it’s only a matter of time before it breaks loose in the rod bore and starts spinning. If you notice on a brand new bearing set, the bearings will protrude a thou or two past the mating surfaces of the bearing seats. As you torque the caps down, the bearings will press against the bore. This is called crush. The tangs on the bearing are for positioning.

[@davidlis6709]

@@wickidflash Thanks - good information

[@Benny-dv7xm]

Anyone out there no how to make a frame rail for an after the fact rotted main unibody on 2004 Subaru Forester?

[@bookerotieno1241]

how do I get to know how to fit a engine mounting in a different car not the original one!

[@davidlis6709]

What kind of motor are your put into what car?

[@johnapaterson]

Thats actually cyl #4 not 2

[@mariosgbodys]

Could you take a look at my latest video? I have tried all of this, and the noise does not go away. I even looked inside the pan, and all rockers and caps have no play or movement .

[@davidlis6709]

Where is our video?

[@davidlis6709]

Your channel is Maria Peralta, why it the title of the video

[@mariosgbodys]

David Lis "350 5.7 rebuilt engine knock"

[@davidlis6709]

I listened to it several times. You tried taking off the spark plug wires one by one and there was no change. It does seem loud under the car. How about this, get a long screw driver and put the handle end on your ear and the other end on the valve cover lip, the side next to the intake manifold. Then move it to the next set of rocker arms and see if you can hear the difference in sound, than try the other side. Maybe one location will be louder than any other. I never tried this but since you have good access to the oil pan, try putting the screw driver on the oil pan bolts starting at the back and more forward as far as you can and see it you can hear a difference in sound. The caps will not have any play. I wonder if one of the rod bearing is spinning inside its connection rod. Maybe that little notch that stops it from spinning got crushed a little when putting it together and is not doing its job of holding the bearing in place.

[@drewdowncutomz4792]

I have a oldsmobile 3.8 and it only knocks when i reve it hard but at idle no noise at all?? Replaced all gaskets about 4 years ago but only used it on sundays also sounded like a exhaust leak but sawpped all gaskets and checked for pin holes nothing sound doenst go away

[@davidlis6709]

Does it skip? Did you check the valve lifters?

[@drewdowncutomz4792]

@@davidlis6709 i replaced the valve lifters and steams same time when i opend up the engine and u cant adjust these

[@davidlis6709]

@@drewdowncutomz4792 With the hydraulic lifters - you take out the slack in the rocker arms then tighten them 3/4 of turn. Some people use 1 full turn. You can adjust them if they are solid lifters but these need periodic maintenance.

[@CapnKanuckies]

Any mechanics out there.. I have a 1998 f150 4.6L v8 that's ticking and the truck is shaking. The ticking is coming from the passenger side around the valve cover which is also right next to the fuel injectors and spark plugs. The spark plugs were replaced with iridium ones and wires were replaced but i'm skeptical about misfire due to the plugs because they're not individual coils. Its 2 coil packs 4 running off each. And it seems to me to be dual overhead cams which take out the possibility of lifters. So my hunch is a bent rocker arm. Im just wondering if anyone else has some insight on this. Also the tick changes with the revolutions.

[@ice788]

Bad shaking is usually a misfire or could be accidentally placing the wrong wire on the wrong plug. I've done it dozens of times. A bend rod would be fucking loud. Like "AHHH SHUT IT OFF!" type of noise. If it's more of a ticking noise that varies with RPM but goes away once it gets warm, it could be a plugged up lifter.

[@CapnKanuckies]

Turns out it was just the plug wire on the back bank got pulled up. And I didn't notice until I reached back there and just pushed it back on

[@broncosforlife88]

My engine is shaking and making a knocking noise . We pulled the spark plugs and two of them had rust and smelled like coolant on the passenger side . The problem all started with the knocking noise and engine shaking and stalling .

[@beau8827]

Someone dropped a hammer in that one,

[@lavalady5571]

Hi David, I have this exact noise but it only manifests when my truck is really warmed up. It drives fine, but very loud knock once it has heated up, and only at low RPM. Do you think it could be a bearing issue?

[@davidlis6709]

When it is cold the oil is thicker and when it gets hot, the oil is thinner. It will run without a problem because the running of the engine has nothing to do with bad bearings. You hear it more at low rpm because as the rpm go higher, so does the noise of the engine and it may drown out the knocking noise. If you step on the gas, does the knocking noise come back. I am asking because as you need more power it is putting more strain on the bearings and the noise should come back. Then when you let off, the noise goes away. How many miles on the truck? Try this: put the truck on jack stands, start it up and take long screw drive and put on end on your ear and the other one on the block next to the oil pan in several different locations and see it you can hear it knocking from the bottom.

[@lavalady5571]

Thank you very much, I appreciate it. It's a Ranger w/ 145,000 miles. It has an overhead cam engine. When I use my stethoscope, the knock is loudest at the power steering pump/bracket and the nearby area of valve cover. So maybe timing chain tensioner, or camshaft, or bad bucket tappet...I've also been told it could be torque converter or flex-plate noise. Still investigating all this. I have tried Lucas stablizer as well as 15w40 oil and there was no change at all in the knock. When I give it gas the noise goes away. It only manifests at/near idle RPMs and when engine is hot. It becomes intermittent before going away completely after the engine cools down a little. Here is an audio clip of the knock taken from underneath the truck: clyp.it/bxzaczm1# Thanks again!

[@mikesaltman]

I’m having the same problem with my 97 Ranger 2.3 but the knocking gets loud on acceleration and kind of goes away at idle or deceleration, it missing like a plug wire went bad and has a serious loss of power. I recently replaced the timing belt so I’m going to check the timing. I’ve had a code for the EVAP solenoid for two years because someone did away with it completely, also have o2 sensors upstream and downstream of catalytic converter. Any advice?

[@lavalady5571]

@@mikesaltman With mine, I can only hear the knocking when it's idling, I can't hear it at all when it's under load. I think yours is something totally different than what I believe mine is (timing chain slapping when engine gets hot). I hope you get it figured out. Weird sounds can be so frustrating to pinpoint!

[@jj0rtega]

We have a 1947 Chevy with a 216 motor. It only knocks loudly when accelerating, let up on the gas and it stops.

[@davidlis6709]

That is exactly what happened to my car. I have no knowledge on engines before 1955. I believe you have a major problem going real bad if you do not have a few repair shops give you an opinion.

[@74nova36]

Facts. It only gets worse unless it’s a tick

[@d70rock]

thats the #4 cylinder not #2, #1 is front driver's side btw

[@davidlis6709]

Good catch. You are right, second one back is number 4.

[@d70rock]

David Lis thanks man, sorry, it was a great video though.🖒

[@davidlis6709]

That's OK. Out of 522,000 views your are the first person to pick up on it. I watch these videos several time before posting but after a while you listen to the mistake and don't realize it.

[@lesterstuck3127]

ok guys i have this 92 chevy p up chevy small block . and the knocking noise is coming from the diverside. this is the thing when i start it nothing after it warms up and i put it in gear that's when i hear it. when i give it gas it gets alittle louder. but when im at a cruising mode it seem to go away.. im so dam confused HELP ME PLEASE

[@davidlis6709]

+Lester Stuck My guess is that it is in the starting stage because when it is not under power you can not hear it but when you need power, like accelerating it puts more pressure on the bearings. Once again, when the truck is just cruising along, the noise goes away. If you put the truck in drive, foot on the brake and slowly press on the accelerator to increase the strain on the motor, does the noise come back?

[@lesterstuck3127]

man i just had the upper half rebuild someone told me this would happen.. soon.. ok i thank you sir for the info..

[@kikapoo7820]

Having same issue did u find the problem?

[@paullancette7725]

Can you say no/low oil delivery as a root cause.

[@lizard5431]

I have some kind of knock coming from my 1982 Toyota Corona (22R) Just did the spark test as shown, when I pulled cylinder 3, the noise stopped for a few cycles but then came back after just a couple more. Lifters maybe? Maybe rod knock on more than one cylinder? None of the others had any effect on the knocking noise.

[@davidlis6709]

Try unplugging #1, then go and take of each of the other cylinders one by one and see if you get the same results. Being a Toyota, I don't think it is a rod bearing. Cannot say100%.

[@mikeb7704]

I have a question when i crank my car the engine makes a sound thats sounds like a aluminum can crushing. Anyone have any ideas?

[@davidlis6709]

Sorry - It is hard to tell unless I listen to it.

[@samialmarzouqi5154]

When I am speed with my car in lomeana , listen mor sound, what's problems ?

[@purewhite84]

Mine sounds just like yours... but it comes and goes. I put a new carb on and it cam back louder.

[@davidlis6709]

If you put on a larger carburator, it increase the hp and put more st

[@davidlis6709]

If you put a larger carburetor on, it will increase the hp and put more strain on the piston connecting rods make it louder

[@purewhite84]

@@davidlis6709 actually it's a smaller carb but this one actually works right lol connect vacuum lines and the knock immediately went away but now it backfires from the muffler when I accelerate. But what's weird is if it's in park I can floor it and no backfire but in drive it backfires

[@ralphhayes7620]

piston broke, should I rebuild my self and hope block OK, OR BUY NEW REBUILD

[@davidlis6709]

How do you know the piston is broke? If you are going to rebuild the engine, take it to a machine shop and have them check it out and if the block is ok, have them bore it out another .030 thousands and install all new pistons. Do you want to keep the old block? I did because I wanted the motor numbers to match the car but if you don't care see what is the cheapest to do. Ask around. What kind of motor is is?

[@davidlis6709]

You should take it to a machine shop and at least have them check it out so you don't waste your time and money.

[@celestahouk658]

what could be the cause of cutting back in a 2.3 motor

[@davidlis6709]

+celesta houk Do not understand the question

[@celestahouk658]

+David Lis my 2005 tribute has bad cutting back after AFC. above 50 mph

[@davidlis6709]

+celesta houk Sorry

[@jesusmimamaeusei]

Chrysler é os melhores motores e mais econômico e mais forte

[@billl2383]

i dont understand how that can work the crank is still spinning so the piston is still moving so the problem is still happening can you explain with som detail why this can work

[@davidlis6709]

When you remove the spark plug wire, you stop the spark and the piston does not fire. This stops the downward force of the piston on the crankshaft and reduce the force on the bearings, so the noise stops. The piston is just following along with the rest of the engine. As soon as you reconnect the spark plug wire, the piston fires and pushes down on the crankshaft bearings and the noise starts again. Understand? If not ask another question.

[@billl2383]

@@davidlis6709 ok i get it the extra umphff makes the knock exposing the problem

[@davidlis6709]

@@billl2383 Yes, old trick my dad showed me. And you can see form the video, the bad ones hard bad bearings on the crank.

[@AnthonyHernandez-lr5uu]

I'm sorry, not underneath the cylinder head, but just above the exhaust manifold (I think you all get the point.) Please, Don't forget, practice safety.Take care..

[@chantellnault3908]

Firing order on a 19996 4×4 Chevy truck 2500

[@davidlis6709]

Don't understand the question

[@Benny-dv7xm]

A real American or Canadian made car. Notice the a\c in the engine compartment and a split box design. This makes it possible to keep from breathing in fungal! So what about for Subaru 2.5 liters.

[@davidlis6709]

This car was manufactured in Van Nuys, California. The A/C is factory installed. The rest of the comment, I do not understand.

[@ethan41623]

I have a brand new chevy 350 3 miles could that be my problem

[@davidlis6709]

Where did you get in from?

[@ethan41623]

David Lis from a Chevy dealer online it came with everything other than headers intake and the accessories on the front

[@davidlis6709]

I would call them up and tell about it before you run it any more. They may want to send someone out and listen to it. It should not make that kind of noise since it is new. If you do start it again or they come around make a recording on your phone or camera.

[@ethan41623]

David Lis ok thanks a lot. Hopefully it's just the lifters

[@These-nutz]

I thought my valves were making a popping noise, turns out one of my headers was loose about 1/8 away from the block, I wasn’t expecting that

[@davidlis6709]

I am surprised you did not feel the exhaust air go by. Anyway, it was an easy fix. Back on the road again.

[@KarahAshleigh]

my car sounds the same!! does that mean it's a rod bearing?

[@davidlis6709]

Could be

[@mikefish4450]

I have a 1986 corvette that makes a slight knocking noise like spark knock only when I’m driving when it’s in park I can rev it up to 6000 rpm and it’s flawless I’ve changed the plugs put a new knock sensor on and adjusted the rockers. And still does it . I’m about to drive it off a bridge and collect insurance money on it . What the hell can it be? Someone tell me please......

[@davidlis6709]

Did you check the engine timing. If the timing is a few degrees advanced on my Chevelle and it is in 4th gear going about 30 mph and I go up a little grade, it puts a strain on the engine. That is when I get that pinging noise. Let off the gas and it goes away, or shift into a lower gear. If I reduce the timing a tinny bit, it goes away.

[@MrRobflo]

Lifter, tap rod, knock

[@davidlis6709]

After I disassembled the engine, I determined that none of the lifters collapsed or any rods were bent. After pulling off the caps on the rods, I saw the 2 of the bearing had been spinning and had scored the crankshaft beyond repair. So I purchase and entire engine rebuilding kit.

[@JavierGarcia-dn4zz]

wow... if its a mechanical problem, shouldn't it make noise with or without the spark? why does noise stop when wire disconnected? what is happening exactly? Thank You

[@davidlis6709]

When the spark plug is connected, it cause the spark plug to fire and this explosion in the combustion chamber pushes the piston down. The piston is connected to the connecting rod that is bolted to the crankshaft and that is where the bearing is located. When the spark plug is disconnected there is no force pushing down, it is being pulled through the cycle by all the other pistons. With a bad bearing, it makes noise, because it has pressure on it and the bearing is spinning around the crankshaft and it should be stable in one spot. That is why this is an easy test. Look at the bad bearing at 6:30

[@JavierGarcia-dn4zz]

Thank You Sir very much for replying, wow I'm very impressed by this fact, I would never have guessed !!! and your explanation is very simple and detailed. Now I'm really concerned about my 76 chevy 350. During my last oil changed., engine was started and made knocking noise 3 or 5 times and immediately shut engine down, turns out the dipstick was misread. oil was added, the noise went away and knocking disappeared, is it possible I might have spun a bearing? Thanks again for your time

[@davidlis6709]

No. When you changed the filter, there was no oil in it when you started the engine. If your car has an oil pressure gauge, you will notice that it takes about 3 to 5 seconds for it the come up to pressure. The reason is that when the engine starts it has to fill up the oil filter first before the oil starts to circulate through the rest of the engine and finally register on the oil gauge. Basically, the engine is running with not much oil on the bearings, etc, (there is just a thin film of oil that did not drain off from the last usage) until the oil starts pumping into the motor. This is the same thing as not starting the car for several months. They are basically designed to run like this on startup because the oil pumps works on engine rotation. What some people do is fill up the oil filter before putting it on. I am not into it and have never had a problem in 50 years. I am an old guy.

[@JavierGarcia-dn4zz]

well, oil change is due again, i'll fill the new oil filter - Thanks again Sire! : )

[@davidlis6709]

See if it makes any difference. Let me know