Why Can BMW Rod Bearings Fail?!

[@SuperJoeTendo]

On my lunch break at BMW watching bmw vids. Life can’t get better than this

[@BmwMe-uh9sy]

wats 4 lunch

[@ronan7812]

@@BmwMe-uh9sy rod bearings in 10W60 oil sauce 😜

[@sunnohh]

@@ronan7812 sad truth mechanical reliability is the only part of the new m4 that scares me, grill included

[@maddog5814]

@@ronan7812 I eat mine like chips

[@armandonika]

Why do the bearings fail?

[@ferenctulics9688]

It happened to me in the past. I used a flexible, but strong enough wire and went trough every feeding oil channel in the engine block and head, crankshaft, etc. I was amazed what the wire brought out and the compressed air didn't... Every little obstruction matters a lot when it's about oil flow or quantity of oil/second! Anyhow, great work! I love this guy! I really like the way he approaches different situations.

[@harveysmith100]

Try pipe cleaners next time

[@NetscapeGuy]

like what? bailing wire?

[@colinwie9192]

Still think it was your oil pump. The score lines you noted on the impeller vanes would have been the cause of fluid cavitation. Again, pumping "foamy/frothy" oil. The comments I made in one of your previous vids regarding all the many Audi/VW oil pumps I've replaced, many of them I took apart and every one of them also did not "look" too bad with score marks/pitting or worn out. Again, the fluid cavitation. In heavy industry like mining where almost everything runs on hydraulic systems, replacing oil pumps is very common even with rigorous oil maintenance. In fact, when I went to diesel/heavy equipment tech training, checking the hydraulic oil for excess cavitation (foamy oil) was a frequent "check list item" to help spot failing oil pumps because that leads to failing valve block assemblies and cylinders, meaning repair bills that'll make BMW repair bills look like chump change. I can't help but note I'm quite surprised some BMW engineer decided to use a Vane type pump as opposed to a Gear/Rotor Gear type of pump. Gear pumps are more durable and more forgiving to contamination (metal debris). Vane pumps, not so much but cheaper to manufacture. In the automotive realm, just about all Power Steering pumps are Vane type pumps and also fail quite often (i.e. loud whining/whirring noise complaints). So I'd guess oil pumps need to be added the "maintenance" list when doing your N54 oil pan gasket. Maybe it's no surprise BMW markets/touts the B58/S58 engines having a vastly improved oiling system.....

[@NetscapeGuy]

Appreciate the knowledge. However, if it was the oil pump then why would the original bearings look fine? It's not as if the oil pump all of a sudden went bad..

[@snivesz32]

I’m so glad you made this video. Also I appreciate your transparency and pursuit of the truth, which is one reason why I watch your channel. That said, there has to be a reason for it, and when you find it it will be obvious in hindsight, keep after it!

[@nissejarnet]

Good video, but the bearings wont change shape with centrifugal forces. When you torque the rod the bearing becomes round :)

[@nealp4280]

This is correct.

[@chrisenright7003]

I called BS on that factoid too.

[@JesseKlompas17]

The bearings are also designed like that on purpose so they do not fall out when installing. The diameter across the bearing is slightly larger than the bore of the connecting rod. It’s called bearing spread.

[@goodlife3655]

At this point I think it's way better to order the bearing kit from the dealer with the VIN, and once you install them the gauging procedure is still required, also the special lube would be helpful during the very first spin.

[@davidfarfan89]

@@goodlife3655It wouldn’t had help

[@joshbrasslett165]

I have learned every inch of my car from this channel alone. Thank you!

[@RJTracing]

The first time an engine runs is crucial, it could be so many things wrong but, let me ask you this. • you probably used assembly lube, but to be sure did you? • did you primed the oil system before cranking it up? Did you reached full WOT pressure during the priming? If not, something was wrong, you should've never ran the engine and check your work and parts. • could you measure the length of the conrod bolts, did they all stretched the same +/- 0.5mm? • did you plastigauge the replacement bearings before final installation? •eventho the oil pump looked okay, were the oil passages for the bearings clean? If you push air thru them, was there any debris?

[@PrinceJohn84]

I've just been through exactly the same situation with King rod bearings. I did mine just as routine maintenance, as the car had previously been abused before I took it on. The old bearings were slightly scored and one of them was showing more wear compared to the others. We went with the CR222SV shells on a standard, unground crank (which checked out within spec when mic'd up). All clearances checked with plastigauge thereafter. After driving the car for no more than a few miles or so, there was a lot of knocking from multiple cylinders and when the car was taken apart again, every single shell was scored and two were down to copper. Thankfully, the crank was fine and undamaged. I decided to go with the more expensive, colour coded OEM shells from that point on and it's been fine ever since. Really, really not sure about King to be honest. Definitely left a bitter taste in my mouth.

[@leoteruel2756]

King bearinga dont use cooper....

[@leoteruel2756]

King bearings CR222SV only use a steel an aluminum layer, thats why they are called bimetal bearings.

[@leoteruel2756]

Your story is false...

[@pennyparker6025]

😂😂 he must’ve been a bmw parts pusher

[@timlad123456]

There was some contamination in the oil system it self, just my humble opinion. The big end of the connecting rod potentially could have been out of round. The only way to tell is to torque the rods and check for out of round with a bore gauge. Best DIY channel on the planet Great work again.

[@dfqnexxus3710]

I agreed best diy channel on the planet

[@tonymontana897]

Yes, I agree. When you mess with rod bearings, you will almost certainly throw the roundness out no matter how meticulous you think you are. It's practically a rebuild at this stage. You should get the rods line bored to suit the new bearings and yes, use new rod bolts. This Channel is one of the best DIY channels out there. He's very humble without the arrogance and pretentiousness of most other channels out there. I'm getting tired of those and have pulled my sub in protest of their non appreciation of their audience who make them rich.

[@AG-wi5bn]

So just my 2 cents here take it or leave it. You are correct the bearings aren't perfectly round what makes them round is when you torque the rod bolts there is a slight crush on the split line of each bearing shell that beds the bearing shell to the ID of the rod. If that crush isn't correct the bearing sits loose in the rod and can spin a common misconception is the little tab on the bearing shell holds the pieces from spinning when actually the rough honing of the rod ID the surface finish on the back side of the bearing shell and the amount of crush to force the bearing into the shape of the rod ID is what holds the shells in place. Bearings normally spin because they are loose fit or in the case of wear the center of the shell gets worn away causing the bearing to collapse inward and eventually spinning because it looses the crush that holds it out against the rod ID. I would be curious at this point to torque your rod caps without the shells and swing a bore Gage through them to see how round they are I bet they have stretched to the point where they won't hold a bearing properly which may be the result of using stronger bolts from arp.

[@davidellis279]

Absolutely spot on,if the rod bearings are not pinched properly in the Conrod when tightened spinning will occur and I seem to remember this guy putting thick oil between the rod and bearings,I have never ever seen this done before in 50years of engine building. Both the rods and bearings should be fitted dry to each other and only the bearings surfaces that face the crank journal should be lubricated with engine oil,I would have checked the rods with a dial gauge to check for roundness and wear without any bearings fitted only then after checking the crank journals to make sure they weren’t out of round would I assemble. The bearings have to be a tight push fit in the cap and rod.

[@MarioDallaRiva]

Quite the mystery! Amazing engineering really with these crazy tolerances and machining. Very interesting, thanks!

[@chrisenright7003]

Do some research on rod side clearance to the crank webs. Not sure if the N54 is afflicted but other BMW engines were constructed with insufficient side clearance. This meant that the oil wasn't able to bleed-out from the bearings at a sufficient rate and got overheated / overloaded. The optimal bearing axial and side clearances vs journal size and rpm are easily looked up - proper tuners know them. Why BMW didn't stick to tried and tested tolerances is a mystery.

[@prayformojo1117]

Just a comment on the rod strength of the N55, they share the same rods as the S55, so it isn't the rod flex that's causing them to spin. Otherwise it would be widespread on S55 tuned engines, which readily make over 600hp.

[@Greasyspleen]

Plastiguage with previously stretched bolts might give innacurate readings. The bolts could be providing too little clamping force due to becoming weak and overly stretchy, or too much clamping force due to "work hardening".

[@ANOTHERWOOK]

I have no idea what's really going on but I love watching and learning and I can't wait for you to figure it out.

[@jimstrongone]

I love your videos, I work as a nurse and love working on cars. Been building honda and mitsubishi engines for 30 years as a hobby. Just started working on BMW's for that last 4 years. Just got done rebuilding my 2nd N54. I've made my mistakes over the years and definitely learned from them. That's why I love videos such as yours. I was thinking about your spun bearing situation. Sometimes it's the simplest this that causes the biggest problems. I don't believe it was the clearances on the bearings or the pump itself. I believe it was the oil pickup tube or the pickup tube o-ring gasket fitting to lose and sucking air along with oil. Like trying to drink a soda from a broken straw. You will register enough oil pressure for the oil light not to trip but starve the engine at the same time. The reason I said this is because it has happened to me with one of my first rebuilds. All my rod bearings were toast. Just a thought. Great job on all your videos my friend. I've learned alot from you.

[@jimstrongone]

One other thing to add, that on that engine that went bad on me the cranks main bearings and cam journals were alright. I'm sure they would have gone eventually but the rod bearings seems to take more abuse and require more oil volume and oil pressure. Once again just a thought

[@kb8512]

I believe you probably used the SV grade King bearings. I built a tuned motor with the same bearings and verified all clearances. It failed at 40k. It ran fine the whole time. Daughter drove it. Her driving habits could have made it worse because she would push it a little more than she should have when cold but nothing extreme. I did an oil analysis at 10k and everything was fine except it had slight amount of silver content. I researched and found the silver was from the rod bearings. I later found out that these engines have coated bearings from the factory. I am building a 2nd engine now and using ACL bearings.

[@smalhfzi11]

Hi pro i will try 3rd. But are you do it wahts the Result.?

[@DearMajesty]

How's the 2nd engine coming along?

[@mikehermesmeglio]

How are the ACL bearings?

[@leoteruel2756]

King bearings dont use silver in their bearings. They use steel and aluminium....anyways, ACL and King use two different type of bearings (trimetal and bimetal), please do your research and decide accordingly.

[@carlfarrington]

@@leoteruel2756 you are hopeless and have no clue what you're talking about. You have replied to every comment where somebody talks about the materials in King Bearings, telling people they are wrong, when it's you who is making things up. King SV is tri-metal silver based with bronze in the middle. SP is tri-metal sputter (hardest, also most expensive, and only highest load-bearing side is sputtered).

[@Ejdw2]

This is better than a murder mystery. Hoping you might present information from an oil analysis. I would think that if the bearings were starved of oil you'd see bearing material in the oil. However, if it was general contamination, I'd expect to see other alloys, steel, etc in the analysis as well. Another thought is to check the small ends of the rods for bearing damage, which would indicate general loss of oil to the crank/rod. Agree with the points of using a higher precision measurement than Plasti-Gauge. Suggest using a micrometer on the crank and bearing journals in at least 2 opposing positions on each journal and a bore gauge on the connecting rod journals. perhaps there's a local machine shop that wants to do a collaboration like you did on the ECU MOSFETS.

[@mozzaarmpit9096]

Maybe a micrometer to measure size of crank journal. Plus dial bore gauge to measure with bearings bolted into rods.

[@jimstrongone]

I love your videos, I work as a nurse and love working on cars. Been building honda and mitsubishi engines for 30 years as a hobby. Just started working on BMW's for that last 4 years. Just got done rebuilding my 2nd N54. I've made my mistakes over the years and definitely learned from them. That's why I love videos such as yours. I was thinking about your spun bearing situation. Sometimes it's the simplest this that causes the biggest problems. I don't believe it was the clearances on the bearings or the pump itself. I believe it was the oil pickup tube or the pickup tube o-ring gasket fitting to lose and sucking air along with oil. Like trying to drink a soda from a broken straw. You will register enough oil pressure for the oil light not to trip but starve the engine at the same time. The reason I said this is because it has happened to me with one of my first rebuilds. All my rod bearings were toast. Just a thought. Great job on all your videos my friend. I've learned alot from you.

[@GoFastGator]

A pump sucking air from a leaky pickup tube would also be aerating the oil which drastically reduces the film strength. 👍🏻

[@bpowa]

This is what I was thinking, since I just did my bearing on my s54. I changed the pickup connecting tube oring to viton. I dont think the oem is viton. It was also loose when I pulled it out. The new viton oring is a super tight fit. I hope I dont have the same issues its terrible scary.

[@cupompa]

Those OG bearings look great after 200k miles!

[@polimeneas1]

I’m not an expert here but when you opened the oil pump the mechanism seemed shifted to the side, was looking at the pictures on forums and the internals aren’t shifted to the side like your old pump? Not sure but worth to check it out

[@polimeneas1]

m.facebook.com/hackengineering/videos/759191681286746/ , this is how the mechanism works, the original engine failure could of caused the middle rod of the oil pump to shift due to extreme or low pressure

[@VehicularDIY]

Wow interesting thanks, I'll pop that back open and take a closer look. Maybe something happened to it when the chain tensioner failed the first time.

[@polimeneas1]

Thinking the oil pump mechanism got seized which caused low pressure and since cylinder 3 is one of the hottest bearings that was the first to go

[@VehicularDIY]

That makes sense, I would imagine it would have just been making low oil pressure. When the timing chain failed the first time it could have vibrated a lot causing stress on the pump. So I'll have to see about how that piece moves on the inside and see if there are any obvious signs of failure.

[@willjay9808]

@@VehicularDIY boom. You got it.

[@greasemonkey1489]

Not sure about N54 but N55 uses a solenoid to vary oil pump output. This is the solenoid at 10-11 o’clock from the crankshaft when looking at the front of the engine. Purpose is for fuel economy/engine load but to ME that variable oil pump can cause oil starvation in the bearings towards the end of the block if there is any pressure drop throughout the system- chain tensioners, VANOS, rod bearing oil clearance, main bearing oil clearance, oil squirters, oil cooler, etc. Different engine, but the Hyundai 2.0 I4’s 2010-2013 were plagued with spinning bearings. To my knowledge there’s no definitive answer yet but what I noticed in the engine I tore down was that the bearing condition was worse as you moved from the pump. The oil pump creates flow and pressure is a function of the flow being restricted (where bearing clearance is critical). If clearance is too high in the other rods or mains, it can starve the other bearings and components further from the pump. You may consider checking clearance on all rods and mains in your search for why your engine failed.

[@yeliabnoj]

This is a quality outlook. "The squeaky wheel gets the grease". I'd like too see a comparison of tolerance to an oil flow diagram.

[@two40zsx]

one issue i find when doing rod bearings underneath the car, is that its harder to keep where the bearing meets the rod, oil free. especially here in CA where our cleaners suck! I usually drop and oil pan and let it sit overnight to avoid oil dripping on me

[@ThePucko97]

Bearings can also fail from too thick oil. If the oil is not considered when using tighter bearings you will get too high pressure and not enough flow to critical parts of the engine.

[@BmwMe-uh9sy]

5w-40 is perfectly fine

[@ThePucko97]

@@BmwMe-uh9sy Yes, however 10w50 and 10w60 might be pushing it

[@FoodFighter46]

But VANOS doesn’t like thin oil. That is why bmw recommends 10w-60

[@konjiki240sx]

You're floating layer of oil plays a big role in preventing metal on metal contact. Additional clearance in your bearings gives clearance for higher viscosity oils that can handle heavier loads.

[@yeliabnoj]

This is wicked smart kid. Probably why race motors run thick oil. Greater clearance, greater power, greater viscosity oil to soak up that load and clearance. I like where your head is.

[@elvispresley8561]

I have 260k km on my N54 and the only things I have changed are the turbos for Td04s at 180 km's and suspension other than that just general maintenance , and it still puls like a train.

[@JQ_Unity]

Vac motorsports makes a baffled/trap door oil baffling for these n54 engines. Put that in the same time the oil pan gasket got changed. I'm drifting so I have much higher chances of oil starving.

[@stellavouxinc.5966]

Not a solution for n54. It would reduce the sump area and how fast the oil returns.

[@markokruc2993]

Always use OEM rod bearings.

[@matt.108]

Had a bad rod bearing as well on my old 07 335i. Oil level sensor had a malfunction combined with a oil pan leak. Eventually the engine ran low on oil. Be careful guys. Especially on early cars with leaks. Ended up replacing the engine with a used one for $1,700. Not the end of the world but still not a fun day.

[@chipjumper]

Used N55 with 140,000 miles are almost $4000 today!

[@hanglin8563]

It’s definitely combination of not up to temp and bearing crush in my opinion. I have the exact same bearings as you, but I don’t have stock rods. I’m using molnar rods with arp2000 bolts. I also have all rrrrrr markings on my crank.

[@BmwMe-uh9sy]

i dont think he would drive it hard unless his oil temp gets up to operating temp has to be engine design failure

[@FairladyS130]

So you think that the after market rods make a difference?

[@hanglin8563]

@@BmwMe-uh9sy the stock rods probably don’t like aftermarket bearings. And the bolts on them don’t help either. I’d probably replace the stock bolts with ARP2000 ones along with the king bearings on stock rods.

[@arnoldmiga5689]

Thanks for great content so far so in return I'll share some experience after owning cars with notorious big ends failures: CA18DET Nissan 200sx modded to twice design power (never failed on me - multiple cars/engines), alfa romeo twin spark 2.0 (stock, two engines failed on me) and a Porsche 924 2.0 (POS). Mind you I don't know N54s so well so consider this as some thoughts/pointers. So IMO the outstanding items for inspection would be: 1. Did anything block the pressure regulating valve in the oil pump. On my 924 I put in a brand new oil filter and the debris from the bad threads found its way into the oil pump and blocked the spring causing no oil pressure condition on startup (all oil run through a bypass valve). I took it out, removed the sharpnel and all was good. Something similar could have happen with yours due to chewing of the chain. 2. Detonation - If I remember correctly, you changed the injectors, plugs and coils on your new motor. Old ones may have caused this. Or wiring going into fuel/ignition components. Can't determine without oscilloscope. I think you also changed the fuel pump afterwards - upgrading to Walbro 255 was the first thing we used to do on CA18's. Colder plugs were also the first thing to do. It could be also momentary overboost condition e.g. due to leaky/wobbly wastegates suddenly sealing but I think you changed your turbos. Would be good to check the boost demanded vs boost delivered on your scan tool (this caused the overspeeding of the turbo on one of the cars I bought due to bad boost pressure sensor but it could work other way round - higher actual boost pressure than indicated). Condition of vacuum hoses, lambda sensors - goes without saying. Be extra careful on those misty cold days - this means air is dense and more of it goes in at the same boost pressure leading to DET. 3. Harmonic balance - aftermarket clutch/balancer instead of stock DMF? Any rattle? 4. PCV system/crankcase breathing - I ran an oil catch tank. On an old motor I found completely blocked breather hose at the back of the engine - possibly a reason for failure on most CA18DET's. Think about the quality of oil in 1980s combined with turbo motors. 5. High revs/load when cold engine - self explanatory, also blows seals on other motors like 350z's that lead to no oil pressure going to the chain tensioners (seal between the tensioner and block) - motor kaputt 6. I don't think that clearances should be bigger if the engine is not loaded with max power (high rpm/high load) for prolonged periods, I ran stock clearances on my CA18DET (1.8 engine with mitsubishi evo turbo about 330 crank hp IIRC, stock 169 crank hp). The higher clearances are used to protect against thermal expansion causing the parts to bind but you'd need some serious load for a long time and with a manual there's less chance of this I would think. Ask yourself how long can you stay on WOT - maybe few seconds - I have an Z4 with N54 and in few secs I'm at 150+ km/h this is licence risking territory so I have to back off. Different story if you are in a very long race. 7. As someone else mentioned, an oring on the oil pickup tube on the entry to the block/pump - maybe it got disturbed during replacement of the bearings? (I can't remember if the ones you replaced failed or the original ones). If you didn't replace this oring then it may be an answer. 8. OEM Oil pressure lights are notorious for lighting up when the oil pressure is criminally low and way below the treshold of damage. On a CA18DET I think it was 5psi or so when normally engine run at 15+ psi on hot oil. 9. Alfa twin spark - these were notorious for burning oil leading to no oil in the pan. Previous owners probably run it dry few times and when I gave it stick it failed. But I think you replaced the bearings and the crank was not scored so probably a moot point. 10 Saab 9-5 Aero - black crap in the oil pan typically killing the big ends - you'd assume we've gone a long way with oils since, yet I saw the same on a Jaguar S-type V6 engine. 11. (linked with 8.) Oil level sensor - these engines don't have dipstick so the oil level sensor could got stuck in one position (gunked up) - I saw it on a replacement alfa twin spark that I got from an alfa166, it was glued up literally. I always ran good aftermarket oil pressure and boost pressure gauges (I never could afford an EGT one) - I think you have all of them anyway. Anyways, don't get paranoid, consider this a normal stuff on modded cars. I had friends with skylines on 3rd engine, same with 200sx, you'd see the same with anything that runs double the designed power despite what people say. But then I question when we call stuff plenty fast. One thing is goals/internet/forums and the other is the real life. I currently run a stock turbo'd Z4 @400 crank hp and its way too fast and too expensive so plan on getting a slower n/a beater for track fun - I don't want to kill myself. I reckon 300 hp on 1200kg car (200sx) is plenty scary (for me).

[@VehicularDIY]

Wow this info is invaluable, thank you! I'll respond back when I can spend some time reading all the points.

[@kevinl2692]

After watched your video and all the comments on kings bearing… I believe the best choice for all of us is don’t use kings bearing😂

[@ericklewis289]

Lol. I just ordered kings bearings but I may have to go with ACL instead. I seen a set online with the extra oil clearance.

[@miceinoz1181]

OK, just a little late in here, but have now seen the original vid of your removed bearings after the oil pump chain failure. From my experience (I started building engines over 50 years ago) when you see "tram tracks" on your bearing shells, you have foreign matter in your oil system as the cause. This is not a wear issue. I have seen bearings with 200K on them and while the load bearing shell (upper) babbit surface is worn down to expose copper, they are smooth across the bearing face. In light of this, your engine should have been removed after the chain failure and all the oil galleries cleaned out and for me, I would have had the crank journals linished at a machine shop and measured as well to see if it needed grinding undersize. I expect having material in your oil galleries has been the cause of this second failure. I would also have removed the mains once I saw this damage on the big ends. A bit long winded, but here in Oz, Beemer parts are cripplingly expensive, so we cannot be too careful, especially on a customer car. Nice vid though.

[@nonamealx]

Have mine with same scores (170000km) on oem shells and still done 20k+ km after disassembly check. So it must been the replacement bearings. The oil filter + oil change also clean these poisoning particles.

[@jcfinch4389]

My thoughts: first of all any debris that gets sucked up by the oil pump is directly put through the oil filter, (I have seen cheap, non OEM, filters split in half before on the tuned n54s I have worked on). but damage from debris will usually leave a sizable groove on the journal and or bearing surface, that being said I think it is safe to rule that out. The only way I could think this might be caused by debris is if the oil pick up some how got blocked and momentarily starving the motor of oil. The temperature mentioned is also concerning, 120 degree oil temp might not affect rod bearing clearance too much but more so piston to bore clearance and if you logged 28psi and the pistons were not fully expanded in bore that might have caused it to unevenly load the rod bearing at close to the max load they can handle. I DONT think you did anything wrong with the assemble of the bottom end. It is unfortunate to see an n54 die, all the reading I have done on building M5x and s5X motors all seem to have a similar theme, sealed, well maintained bmw motors that are tuned within their limits will out last any motor that has been tampered with no matter what parts or how carful/experienced you are with reassembly. best of luck with the new motor. keep up the great content :).

[@coynor1]

with what happened prior with your chain sprocket and all that metal it had to slowly plug up one of your ports until it wasn’t getting proper oil supply. Then laying on the petal without you’re oil being the proper temp... boom! Love your video’s man say it every time.

[@bence.gabor.slezak]

Whatever you get in the oil will be caught by the oil filter, that's why it's there. Plus you need a ton of metal shaving to block an oil passage.

[@coynor1]

@@bence.gabor.slezak he spun a bearing before his next oil change. Also before he did his rod bearings one of his sprockets shaved metal throughout the motor. So what are you thinking what happened?????

[@bence.gabor.slezak]

@@coynor1 do you actually believe the oil filter isn't doing anything?

[@coynor1]

@@bence.gabor.slezak never said that, That’s what a filter is there for. Doesn’t make my theory impossible

[@coynor1]

@@bence.gabor.slezak you’re right no motor has ever blown from debris in the motor. The oil filter caught everything

[@ichoozjc]

VAC and King sell tons of bearings. Many have swapped and most don't have issues. My guess is....I have no clue. Dang it! Like someone said, I'd triple check that oil pump.

[@VehicularDIY]

Yeah I don't think it's fair to point any blame on those bearings at this point.

[@TheFrenchPug]

I think they said "oil cooler".

[@ichoozjc]

@@TheFrenchPug No, oil pump.

[@ssswdon]

Another trick of performance engine builders is they will swap a top bearing and a lower bearing. Meaning the top bearing will have one thickness in the lower bearing will have different. This is how they get the clearance that they need for high performance application

[@DailyDriverTracking]

The ellipticity ratio of the aftermarket bearings may have been different.

[@Juni0r2323]

Any follow up videos to what happened to this engine or oil lab results ? I’m going to tackle the job of changing my rod bearing ( given the confidence by watching your videos & links to parts & tools ) took it to BMW said they used a camera & said something knocking on Cylinder 1 & 2. Gonna send my oil to get analyze & see what comes up. NEVER did internals but pretty meticulous about doing everything right. I already done a n54 swap, I got a second motor that I will practice & see if I build up but want my engine inside the car to get back running before I go crazy spend tons of money on something I never done before. Overall LOVE the content I’m a new viewer, would love if I can ever reach out to you with questions ofc I’ll PayPal or donate to your build for any help. Thanks bud keep up the great content

[@JackRR15]

Wow man when you mentioned oil pump I was like that must be it. Damn idk

[@chrisgarland99]

I know I’m late to the party here but I’m about to change my tubes and am thinking of doing the rod bearings at the same time as Blackstone report found excessive lead in my oil and suggested that it from bearings. I was planning on upgrading to the ARP bolts but now I’m rethinking based on your comment about them in this video. What did you base this comment on? Im having an experienced BMW shop do the work but just with the oil pan off so not able to line hone.

[@kalalaboka]

in my opinion it could also have been due to the assembly oil. That looked very thick. Almost like fat. May have clogged the holes at the beginning.

[@auszman]

I have an N55 that failed the no1 rod bearing TWICE within 20 km. Priming of the oil pump and oiling system is critical - airlocks in system I suspect. if not done bearings spin. My research reveals that if they do not spin immediately than enough damage is cause that they spin soon after. my experience anyway - third set of bearings going back in shortly with primed pump, primed system and oil pressure gauge to confirm oil pressure drops from potential airlocks. This included priming oil cooler if you have one fitted.

[@SavageBunny1]

1) There a perfect circle when inserted in to the rod, not out of the rod. 2) You're "egg shaping" the bearing torquing and loosening the rod without shimming the rod with a file gauge. 3)Check the oil pick up tube, it might be clogged, when the serpentine belt goes out, it sucks it in the engine, and people replace the front main seal and never take out the oil pan and check what's going on in the engine.

[@neilsimmons9582]

I know I'm late to this but have 2017 X5m 60k miles and out of nowhere have bad knocking noise due to rod bearings. Mechanic recommends replacing the engine but I'm wondering why can't the rod bearings be replaced. All maintenance have been followed and very light miles.

[@andyjohnson9714]

those bearings DONT SPIN, hence no centrifugal force applied to their expansion.

[@machtschnell7452]

120° F should have been sufficiently warm at anything less than 3/4 throttle. So you say the oil pump chain tensioner failed at idle yet you do not think it caused the spun bearing? You might also want to inspect your Vanos pump just to be certain no metal parts went through it. Thank you for taking the time and posting.

[@VehicularDIY]

So the oil chain tensioner failed at idle but the chain was still on and came off while driving after. Then I fixed all that and put new rod bearings in and they lasted 1k miles. So the stock bearings are what would have been affected by the chain coming off by they still look great. Someone brought up a point that the oil pump could have suffered damage. I opened it but have checked it completely. The shock of the chain dancing on the sprocket could have compromised the oil pump internally.

[@timwooton6837]

When checking rod bearing clearances with plastic-gauge use the old rod bolts and torque AND stretch the bolts or your reading will be off. You can only torque and stretch the rod bolts twice so plan on buying new ones. Also if you’re thinking about using the ARP rod bolts, don’t! If using ARP bolts you’ve gotta assemble the connecting rod, torque, stretch then line hone cause it’ll egg the connecting rod-ask me how I know.

[@bence.gabor.slezak]

Some say when tightening crank/rod/head bolts it is good to do the whole 70°/90°/150° or whatever in one go and not stop. That's the only thing I saw in your video of changing the bearings, but I have no idea about the science behind it. I might ask a mechanic friend of mine, he's done a few engine rebuilds.

[@jetro7349]

Watched the whole video and really seems like the culprit are the bearings themselves.

[@busterscrugs]

Damn, was hoping we'd find out a definitive cause. In regards to oil temp, 120° is a bit on the low side if you're talking Fahrenheit. Still not entirely certain that would be enough to spin a bearing, especially with the bigger clearances of the aftermarket King bearings

[@VehicularDIY]

Yeah the needle has just started to move .

[@paulsimpson8990]

My needle is off at 70 degc. 120 is less than 50 degc and the oil viscosity would be perhaps 60 or more cst at that temp. By comparison a 10w60 is 25cst at 100 degc. People worry about thick oil but at 50 degc you were running at least two times thicker oil than a 10w60 at operating temp and no les than times 5 thicker than factory fill.

[@pippop94]

Interesting videos man, have you considered having your oil lab tested for contaminants or clues? Had my n54 fail on cyl 6 bearing and lab results indicated high fuel content in the oil caused by leaking injectors. Never followed up if this was the cause of the failure so would be curious to see any similarities. On a new engine now and I get my oil tested every oil change.

[@BreezeLock]

If you flushed your old oil cooler im curious if you would find debris.

[@VehicularDIY]

Good point, I could check it.

[@alexeimaterov3226]

I'd imagine most of the debris is in the oil pan still and oil pick up tube.

[@TheFrenchPug]

@@alexeimaterov3226 He cleaned it all out already and had some debris in it.

[@FairladyS130]

The caps on those rods look weak around the bottom part, that's particularly relevant at high revs on the over run.

[@DearMajesty]

I watched this from another video. Was the engine primed with oil before being started again after the repairs???? Idk just a thought...BMW has a technical bulletin on this

[@michaelroloff2804]

The tendency for the connecting rod bearings to wear out earlier at BMW than at other premium manufacturers is something of a "tradition" and is also based on the fact that the crank pins as well as the main bearings are relatively small and narrow in diameter. This facilitates or benefits the engine's engine revving power, which is already legendary at BMW. However, one must also note that some contemporaries tend to be careless, if at all, with warming up. Internal combustion engines now have a work area in which they function optimally. The cold state of aggregation is not one of them!😉

[@igotaction]

What did the oil filter look like? Could it have been one time foreign object damage? (Piece of tensioner or something). Generally after rod bearings or new internals you would run for 30 mins and change oil. Thanks for sharing sorry that happened.

[@VehicularDIY]

Oil filter had bearing debris material but didn't see any signs of any foreign material. Thanks

[@devonsmith1995]

I wonder if anyone has an upgraded oil pump that would help with flow volume on start up and cold starts to help prevent wear on the bearings.

[@VehicularDIY]

Yeah that would be worth looking into.

[@matt_h537]

@@VehicularDIY I have a few oil pumps. I am really leaning to the maybe I will pull my bearings just to compare how they look, we did put them in basically the same time.

[@paulsimpson8990]

Note that the oem pump is a pendulum pump and even though it uses vanes like any pd pump it varies the flow by pivoting and thereby reducing the flow rate.

[@yeliabnoj]

Of you remove the oil supply line to the pendulum it defaults to full pressure

[@chrisbelcher5320]

The. color codes sizes. rrrrrr are all standard, upper and lower, the the other colors would be ,5 and .25. Last year I done all new king rod bearings and and arp bolts. I done everything to a t, I done proper break in, around 1500 miles, I lost nu4 rod. I’m in the same boat and can’t find a good answer, and this motor is 60k on it. I couldn’t find any answers, but leaning towards detonation. I run 93 and around 18psi on 16t, but they all looked like yours. I’m thinking the king are much harder than oem ones, but can’t justify the price per shell. I’ll try it again and see how I make out

[@steveallam]

I'd change the oil cooler and flush out all the lines blow out all the passages. I would measure the con rod at several points on it's circumference for elongated and twisted also i wouldn't go for a bigger gap... maybe its time for aftermarket conrods and have them cryogenic treated then get the ARP bolts then get then check afterwards and do what ever machinist needs to do to get it true. And balance the con rods with the bearings and same with the pistons then all with the crank. It would be a good ideal to see if the the crank journal is flat maybe at one point on it 🤔...

[@TheFrenchPug]

I thought he did change the cooler out already.

[@csmitas]

currently in the process of building my N54 - i spun a rod bearing and then had a machine shop take off 0.25mm on all the journals. I'm putting in oversized 0.25mm king bearings that are calico coated. all of my clearances are pretty much the same as yours, roughly 0.038. still wondering what happened here, and hoping this doesnt happen to me haha

[@TheFrenchPug]

Gonna comment here in case something does happen maybe you can update us? No knows will be great news though :)

[@rv6ejguy]

If you have 38 thou bearing clearance, you'll have a hell of a rod knock...

[@csmitas]

@@rv6ejguy 0.038mm is what i meant, or 1.5 thou

[@johnarussoii]

Just did mine as well. Had #6 spin. Did some polishing on the journals and all journals were .053mm except one which was .038mm. This just after purchasing the vehicle at 101K miles. When dropping the pan it had new gasket and the pump looked brand new so I’m suspicious of what the seller was up to. I’ve got 0/40 Mobil 1 in it and about 200 miles on it so far. Will keep you posted.

[@csmitas]

@@TheFrenchPug update: engine now has about 8000 km on it running ~30psi from a single turbo and no issues at all so far.

[@BMVaaay]

So would it be smart to use 0.25 bearings for a high performance application with a std crankshaft

[@markt9438]

Being that you put new bearings in your system obviously was malfunctioning I suspect the oil pump for sure there's got to be a way to know if the oil gets air in it That's one thing I'm not sure about how to figure that one out but if the crank case is overfilled it will definitely foam your oil

[@herlegz6969]

This is so heart breaking. and confusing. Did some debris despite all the flushing not get removed? Did any oil related valve or VANOS piece somehow cause a oil pressure drop? Have you inspected all the oil passages to see if something clogged and then bearing failed and then creating debris to etch the rest?

[@VehicularDIY]

Yeah if all the bearings looked good I would have just assumed it may have been debris but they all were marked up so reduced oil pressure is the only logical explanation.

[@larryhedrick7657]

The part I forgot to add is that in this condition it will drop the oil pressure significantly making the situation worse. Just a theory but I will be verifying my findings this week. Thanks.

[@dkoz8321]

Looking at this guy tear down BMW N54 motors, makes changing gear accessory box on AH-64 Apache turboshaft engine, seem simple.

[@swiftautomotive4014]

Did you also use 5W-40 with the stock bearings or did you switch to 5W-40 when you changed to the king bearings?

[@GoFastGator]

I'm going to start this off by saying I love watching your vids, and I don't even have an N54.... ('11 E90 335xi M-Sport 6MT) Yet I watch just about all of them. lol Plastigauge is a ballpark check. It surely will indicate if you did the math wrong (from mic numbers) or have a wrong size part, so it's not like it doesn't have value. It's just not going to be accurate enough to compare tolerances between OEM and Aftermarket bearings, IMO. When you use PG, it's critical that the joint is immobile. In your case, it looked like those rods were swinging free when you torqued them down. Normally the piston in it's bore would hold everything still while you're torqueing those rod caps. Maybe call around to a couple automotive machine shops and see if they won't be able to get you some more precise numbers?

[@VehicularDIY]

Thanks for watching! Getting my hands on a micrometer would help.

[@Mike4444x]

Have you checked with the manufacturer of the bearings for their input?

[@VehicularDIY]

No yet, I am planning on it.

[@bigfwopl4873]

Micrometer and torque wrench calibrated perfectly? If no It’d probably have to be hellish variance anyways so Idk. I’m afraid to go upgraded bearings for this exact reason.

[@VehicularDIY]

Yeah given these engines come with pretty tight clearances from the factory I don't think plastigauge should offer much of any assurance when changing bearings.

[@craigellsworth3952]

Plastic age is still a good check. There was a guy a few years ago that changed his N55 rod bearings. After changing one of them he was unable to turn the crank. A check with plastic age confirmed that it was in fact a thicker bearing. The box had the intended bearing size stamped on it.

[@Antimatter.]

Can it be like you said ? The King bearings had more clearance and possibly decreased oil pressure to the journals causing the bearings to score ? Is it possible to have installed the bearings in the wrong orientation?

[@romuztek]

Hey man, do you think your manual conversion and SMFW swap could have anything to do with this? I figure engine harmonics may play a factor if you kept the auto harmonic damper/balancer on, especially if you changed the transmission-side dampening characteristics with the SMFW. Just spitballing here since the N54 is an i6 and everybody seems to ignore engine harmonics because the N54 is supposedly indestructible. Really depends on whether you were doing prolonged high RPM stuff aswell though.

[@strongme80]

Purchase a dial bore gauge, reassemble the rod including the bearings along with proper torque angles on the fasteners and note down all the numbers. Then use a Mitutoyo micrometer on the journal range and mic all the crank journals at X and Y and get the numbers so we can see the true clearance. I would NEVER EVER use plasti gauge and a caliper since those read back ball park approximations! I bet you'll find the reason why the bearing spun, the numbers will tell you.

[@taylor1942]

I don't know if you've ever seen any of papadakis racing videos here on KZbin but he shows you how to build an engine and check for bearing clearances and it says plastic gauge is great for just generally checking it but it's not accurate, maybe you can borrow from your friends at that auto shop the tools to properly check the bearing clearances to get a better idea what the actual real clearances are between the stock and the King bearings

[@VehicularDIY]

I have, that's a great channel. Thanks

[@taylor1942]

@@VehicularDIY Curious will you be doing a follow up video on this? :)

[@doneB830]

Mic it up properly ( ovality and taper both rod and journal), check the conrod for straightness and only use genuine parts if then no fault is found the fault is somewhere else like the oil pump, resonance ect.

[@bigt060654]

Is it possible that some of the bearings were the wrong size but still packaged with the correct ones ? There’s been many stories of KING packaging undersized / oversized bearings with standard sized ones on bmw forums … I’m going to do this job on my 07 335 and ordered the STD sized bearing from KING and one of the bearings were undersized and the rest STD. I had to reorder and check every individual one to be safe

[@Mirzo_99_]

2013 bmw x1 (n20) Rod bearings have failed yesterday. Loud n clear knock 😔

[@nonamealx]

not relevant, complete different motor/bearings

[@clh3385]

Sound like a common issue related to all bearings. No oil prime on start up plus low oil pressure. What’s oil pressure at start up?

[@indianboy0453]

Hope you havent already answered this but the N55 has a known issue where the chain tensioner fails. So much so that theres a class action lawsuit currently going on regarding failed N55 engines due to the chain, the chain tensioner, and the oil pump. Do you think those characteristics were born in the N54 and carried over to the N55 or is it a completely different issue? Absolutely love the videos! Keep em rolling!

[@paradeinberlin]

You are correct to a degree, the exhaust and intake cam gears can come out of alignment and skew the timing with low oil temp or incorrect oil weight and improper load. I’ve done this with my N55 and I had to redo my chain, guide, cam gears, etc

[@paradeinberlin]

@@laserjet6941 like standing viscosity or viscosity at a certain temperature

[@Areku06]

Wrong, N55/54 are not known to have timing chain issues, that’s N20/N26 motor lawsuit. N55/54 is known for oil starvation at high G, solved by adding baffled oil pan. Also some people don’t prime their engine after ofhg and throw a rod.

[@LMLracing]

So changing. The bering with kings bering is no good ?

[@bigbothoee8617]

Did you prime your pump after new Install ? I normally install then prime oil pump till oil flows out of cam caps without rotating engine

[@Nico_335i_DCT]

Thanks for sharing! Well an Austalian guy which owned the drag e9x WR on a stock not opened n54, says these high performance n54's need 10W60 like the ///m engines run on. But that's maybe because of the warm weather out there? His car is now owned by Dave and Andrew from zeroto60 (youtube). It's now a daily on 700wHp. Dutch regards, Nico.

[@VehicularDIY]

Thanks for the info! That's interesting that you can run 10w60 even in hot climates.

[@scooterfree62]

Did you measure the thickness of all new bearings shells? Did you plastic gage all of the journals for the proper oil clearances

[@BigUriel]

Maybe I'm missing something but it seems pretty clear to me what the variable here is, you had OEM bearings for 200k miles then you put aftermarket ones and they spun almost straight away - it's the aftermarket bearings. They're probably designed for racing and not to be used with the stock oil pump or to ever be revved at all until the engine is up to temperature. Which makes them a terrible idea for a road car.

[@ben7020]

I remember you replaced bearings with that thick pink goop. I've never seen it used before and feel its use may be suitable for camshaft lobes- not so much for enclosed bearings. It suspect it prevented oil flow as it would take huge pressure to puch thick goop out of tiny oil clearances. It's like using 400 weight oil if you get me. Thanks for the videos 👍

[@VehicularDIY]

Thanks, It was recline assembly lube, I would assume it's suitable for a bottom end but maybe with such clear tolerances a thiner assembly lube would be better

[@gaboonviper85]

Typically assembly lube is just fine

[@dfqnexxus3710]

Any new improvement for the e90 ? Wanting to see any other upgrade from you like coilovers

[@TurboArt1]

Thanks for the info doing rod bearings on my e92 spun one.

[@diablocls55]

Did you ever get it done? I don’t own a BMW but I have a Benz E550, and my brother just spun a bearing in his 2006 Honda S2000 today lol

[@xushenxin]

Bearing needs clearance and oil. If clearance is good, then it is the oil pressure or carbon deposits in the oil, large one.

[@utube321piotr]

To properly do what you are doing, you must first immobilize the crank in the block, then stick a piston w/o rings on the rod and stick it in the cylinder block prior to torquing the rod up on crank. Otherwise the rod and crank moves about during torquing and you are "smearing" the plastigage on the rod journal getting wrong reading. Besides, measuring in 2 planes with a mic the journal and rod is more proper than plastigage.

[@777-e5t]

Smart guy, thanks for the information!

[@LdtEntertainment]

thanks for explaining the process! love your content

[@glenglene8473]

during the oil pan gasket change on my N55 E90 at 103K miles, I removed one of the rod bearing caps to examine the rod bearing. Since the bearings looked good, it buttoned it back with two new bolts and 20NM plus 140 degrees. After buttoned up, I tried to move the rod bearing laterally, and noticed the movement is much less than other five rod bearings. Wondering what caused it to be tighter?

[@VehicularDIY]

Did you do it in two stages of 70 degrees when tightening?

[@glenglene8473]

@@VehicularDIY yes, 70 and 70. Engine seems to run OK now, but I hope tighter clearance won't cause a spun rod bearing later.

[@ichoozjc]

You might have just had more tension on the rod, like the piston was pulled up in the cylinder further. Just a guess. Shouldn't have made any difference with new bolts.

[@roadarmord]

Me too, I notice a diebres last week on my freshly build engine after just 2000km , I ordered ACL ( same standard size) hopefully I still could save it 😪

[@ericklewis289]

I seen ACL bearings with extra oil clearance. Did your ACL bearings help out?

[@thisguyshorty3554]

What oil brand/weight were you running? Could the oil you used to flush the engine cause it to ruin your bearings? I thought you used a non synthetic oil to flush it.

[@pyroguy61]

I’ve got a f10 m5 it’s got a knocking noise I believe this happened after a 2nd gear pull but I’m not sure degeneracy did not drive it after I heard the noise. dropped the oil filter there is definitely a hint of some shavings, you think I might be able to get away with just replacing the bearings or is it too late?

[@nickgarner1790]

so a wives tale on that topic is if you dont have severe rod knock then you can probably get away with just doing them and making sure the crank face and the rods faces are not scored to bad. just know if it is knocking the more you drive that engine the more expensive it gets to rebuild or worse you end up running the crank and bottom end. One of my good buddies bought a 2008 m5 a few years back and hes in the hole trying to get that car back on the road lol... but your generation is 20x more reliable then the e60s

[@hatkeeper]

You mention when it failed. The temperature is 120F. Was it coolant or oil temperature? From the N55 In the warm up phase, the oil temp lags the coolant by 10C and (below 120F, oil pressure is ~100psi; over 120F it drops back to 40psi; will double check)

[@VehicularDIY]

That was oil, coolant was up to full operating temp.

[@jafarhon]

Hey Buddy, i assume you are running King bearings on your car, is it still kicking ? im thinking of buying kings for mine, need some advice. Thanks

[@cali_cal]

incline/ hard acceleration causes oil starvation

[@chrispy104k]

Are you absolutely sure that there was no detonation occurring due to a bad batch of fuel? Is there any sign of detonation on any of the pistons?

[@VehicularDIY]

As far as I can tell no, pistons look perfect

[@bernardoalvarez1595]

I have the same problem. I change mi rods oem to King bearings. After 1000 km same issue