Ford Ranger 2.3 2.5 Stalls After Rev Rough Idle Fix (Recessed Valve Seats)

[@everydayirace]

you're right on the money, fb experts will tell you 40 different parts to changed while most couldn't tell you what ratchet is, forums were better, but most don't come back and say what fixed the problem lol. Subbed.

[@bitscollins]

You're the kind of mechanic I've been looking for for years!! Too many computer nerds pretending to be mechanic's these days!! My hat's off to you.

[@1duder13]

I’ve been battling the same issues rev high runs rough and occasionally dies issue. Saw you video and tried the dolled bill test and failed. Pulled the head and definitely recessed seats. New head on and runs great. I don’t think I would have come to this conclusion on my own after good compression, leak down and manifold vacuum test. 1997 2.3 176k miles however the old head looked to have junkyard markings on it. Thank you for the excellent video!

[@TheVintageEngineer]

After all the frustration I had, I knew I had to make a video. Knew there had to be others that had the same issue. Sounds like the dollar bill test is the best indicator.

[@massonwise3692]

I want to take the time to thank you for your post. Its really hard trying to come across videos for a 2.5l. I have a 98 ford ranger 2.5 myself. And been having issues of what you explained in your video and me and my dad have sat here and repleased parts after parts from fuel injectors to maf sensor to the tps to running test to see if the catalytic converter is clogged to testing the egr and running pressure tests on the fuel. But from the sounds of everything youve experienced and what it turned out to be i believe myself that i also have that same issue and if it wasnt for your video me and my dad would still be stumped at trying to figure out what was wrong. I thank you very much.

[@TheVintageEngineer]

Masson Wise why I made the video. Too many dead end posts with no resolution. Let me know if it’s confirmed on yours after a head pull.

[@aashanarana7906]

@@TheVintageEngineer did machining your heads fix your issue with your truck ??????

[@000001willy]

I heard one possible explanation that the problem could be a crack tube which would drop the pressure in the line at idle as explained by my friend who is an amateur mechanic. That might be the problem but you have definitely identified the type of problem that would cause my engine to stall. Thanks to you for all of your sleuthing hard work. I just hope it's not going to be too expensive to fix the problem.

[@Stretch-ld8yv]

I appreciate you for taking time to show and explain this

[@jameschester821]

Thank you. My suggestion also... Test DPFE Sensor and wiring harness. That causes the same issue. Mine was the DPFE Sensor. 1996 F.R. 2.3l.... However, I know many of them that simply was no answer for. Thank you so much for this. And the explanations. You are the real Power Ranger. Thanks

[@TheVintageEngineer]

Don’t remember if I mentioned it in the video but I monitored the DPFE signal during drives. Pretty much tested everything under the sun before pulling the head. No need to do more work than you have to.

[@jameschester821]

@@TheVintageEngineer you did not mention DPFE, but that doesn't take away from your video. It is the most complete and helpful video I have seen. Thank you for the explanations on each system tested and the drawings. I did add a link to this video to "The Ranger Station" forum along with "Scanner Danner"'s DPFE EGR vid. Once again, thank you.

[@jameschester821]

The DOLLAR BILL TEST... Priceless

[@DuttonWebb]

Gosh thank you for posting this. After having my sparkplugs, sparkplug wires, fuel injectors, and ICM replaced, my mechanic made an epiphony and found this video. It's my cylinder number 1 not firing at idle. The symptoms match perfectly whats happening with my 2.3. Having the head sent to the machinist next week to have better valve seats installed. Swappping the engine fan with electric fan too for a little extra hp! Can't wait to have a little balls put back into my throttle.

[@DuttonWebb]

Well the guy didn't want the job so I've been driving around on 3 and half cylinders for a year now. hahaha

[@jimmystanhope2408]

I have a 99 ranger 2.5 with the same symptoms. I'm a tech and haven't been able to figure this out. Thank you for the detailed video.

[@TheVintageEngineer]

Jimmy Stanhope I think a good indicator of this was doing the “dollar bill trick”. Now I don’t know if this shows up for sure on all the trucks that have this issue but it did for me. I held the bill flat against my palm and held my palm maybe an inch or slightly less away. It would push the bill back against my hand most of the time but every couple of seconds it would suck it towards the tail pipe. Probably one last thing to try before pulling a head. You could also endoscope/bore scope the cylinders and see how the valves look when seated. If they are proud of the seat then they are good, flush and sunk below is bad. I thought originally they should be flush but the rebuilt head had my valves 0.050” proud of the seats. So a flush valve is 0.050” sunken. I may upload my follow up video later tonight for you to see what I mean if I still have it.

[@TheVintageEngineer]

Here is the follow up video: kzbin.info/www/bejne/mJq9n51nbpaLg7M

[@ez5344]

I'm confident that your video just solved the issue with my brother's truck. Doing exactly what you described. We have changed everything and still doing the same thing. I appreciate you for uploading this video. Will come back an update after checking out the head. Thnx

[@TheVintageEngineer]

The dollar bill/receipt test is what did it for me. You try that when it’s running bad?

[@toddcoates5584]

Hello, just got thru replacing a 2.5.Its been a mess but finally in the truck.Now if you rev truck up a few times ,let go back to idle,it lopes and almost or stalls out. Everything is new ,coils,plugs.wires , good compression.no codes.I guess your ifo has guided me to a new direction..Thank you for your time ,and school of hardknocks for all of us.

[@TheVintageEngineer]

See if you can get it to run bad and do that dollar bill/receipt paper against the exhaust trick. Just about the only thing I could get to show an issue

[@toddcoates5584]

Hey thanks for the reply,it's been a mess..you Rev it a few times,runs rough at ifle.a few more secs it smooths back out..runs great except for that..worse part it's for a family member ,,free bee lol. Thanks again

[@slowawdyoutube8372]

Will be doing compression check first. Then pulling valve cover and trying to see that way. Avoiding pulling the head as much as possible since my manifold is crusty. Really appreciate the information. Tried dollar bill test and kind of feel inconclusive about it. Tried marvel and honestly did seem like it helped. Battling low oil pressure atm but suspect it's the switch which I will replace soon. New iacv. 10k on plugs and wires (exhaust spark are unknown atm). Basically same thing as stated. Rev to anything above 2500 and drop back to idle the STFT jumps 15-20-30 almost before trying to stall. Push the gas and idle smooths right out. No issues in daily driving at all. But coast into a parking lot from 2nd and idles rough again. 2000 2.5 XLT 180k miles 2wd 5Speed Fingers crossed youre wrong but I'm positive you're right man. Very informative

[@ijustvibe6095]

thanks anthony. same issues and have not pulled the head yet but from the intake view and top view i have to say itself looking like we got a an outbreak of resessed valves. '03 ranger xlt 2.3 liter symptoms were similar to yours. Initially from the no more good forum posts i started with iac valves, to intake. everything checked out normal until i open her up . Also will be using a locsl machining shop ..or who knows maybe a new head . i love my ranger. regards and thanks again for the great informational video.

[@mikehaglund7283]

Sounds just like my 96 Ranger, erratic running, stalling, gutless. Fought with it for a couple years and replaced every sensor on the thing despite no codes. Made no difference and finally pulled engine and put a $150 junkyard motor in. That ran great for 2 years, but got blown up by one of my kids who does not bother checking oil. So back to trying to rebuild the original engine. Noticed the valves were visually much farther into the seats on the original head than on the blown motor. I measured .054 difference between #1 exhaust valve on the two heads using the same valve, so even worse than yours. Thanks for the video. Now I have to bring the heads in to machinist to see if head off the blown engine was damaged by piston hitting it from broken rod, or not. If so then I will probably try to locate a replacement head or see if they can put inserts in the valve seats of the original head with the sunken valves.

[@TheVintageEngineer]

There is another view I made right after showing the reman head vs this one. They actually are about 0.050” proud of the seats on the reman. Rebuilder looked at mine and magnafluxed it and showed tons of cracks. He said the seats wearing cause the material to be too think between valves and makes them crack. He said pretty much every Ranger that has sunken valves needs replacement, unless the rebuilder can do crack repair.

[@mikehaglund7283]

@@TheVintageEngineer Yes, my two heads show that big visible difference with the blown engine head having the valves margin sitting well above the seat and the original engine that ran so weak and erratic having the valves edges invisible cuz they are so far down in the seat. I think I am going to just get a new head and valves. Even though there really does not appear to be anything wrong with my valves themselves at all. Can't figure out why the valves hold up a lot better than the seats. None of the places I looked had rebuilt heads for less than $540 plus shipping. And I looked around for a while.. Perhaps if the variance was not too great a machinist could take a little off stem length to compensate for a short term fix, or cut the heads to have seat inserts put in (assuming they are available, but then there is the issue of likely cracks and I have yet to bring a motor to a machinist that did not think it needed to be bored out, new pistons, valve guides, seat inserts, etc. Turns into an exhaustive rebuild every time and more expensive with every motor.

[@richardbarrett6995]

Replaced the head on my ranger at 170k, ran perfect. Less than 10k miles later back to doing the same thing....

[@dogsandwich77]

My '99 is currently looking exactly like this, head will be here Monday. Just pull the head off, it will set you free. I spent two years banging my head against this truck as it got worse and worse. I'm glad I stopped driving it before it dropped a valve into a cylinder and wrecked the bottom end too. Dont even bother with a remanufactured head, get a new one. I put a whole remaned engine in mine (valve broke and smashed a piston) and it went 20k and started misfiring , put another 10k on it before i finally gave in, pulled the head, any saw the valve recession i knew was happening. I have so many unneeded spare parts now that I can build a whole 2nd damn truck.

[@kodycraft4425]

Man, wish youd have made a tutorial on how you pulled the head ! Alot of videos were by the book Lol but almost 100% sure this is my issue . Super informative video !

[@boydlittou9446]

Very good video Another problem with machine shops rebuilding these heads is them not setting valve stem height right. These engines are very sensitive to valve stem height and you got to really watch casting numbers to be sure stem height is set right. Some are 1.9350 to 1.9650 and some are 2.060 to 2.070

[@TheVintageEngineer]

BOYD LITTOU oh I’m sure that has a major influence. But I guess you can verify it after the fact by check clearance at the cam/follower with a compressed lash adjuster.

[@rileybush6459]

Really great background info, thanks so much. I'm going to have to do some testing and see if this is my issue. It has all these symptoms, plus an occasional rattling sound when accelerating under load.

[@zackmartin5563]

I have been chasing this exact issue and have had no luck trying to find a certain path of diag to follow. You just described my issue to T.

[@TheVintageEngineer]

Let me know if it’s the same root cause

[@kevinmcmullen8047]

Finally thank you been racking head for months

[@buddysmilesgaming193]

My 98 ranger 2.5 is doing the same exact thing and like you said, I replaced every sensor on the motor and the pcm, will be taking the head off this weekend to see my valves because it HAS to be this! It's been sitting for 15 years so I put another motor in it from another ranger and they didn't tell me they were having motor troubles till I installed it >:(

[@TheVintageEngineer]

End up being the valves?

[@johnmcmullen456]

Really appreciate this video. Could use some help. Had cylinder head completely rebuilt on my 1988 2.3 Turbocoupe by a machine shop that specializes in race engines, about 1,000 miles and 2 years ago. Rebuild included new valves, seats, guides, lifters, springs, and performance roller cam. I have a rough idle and the tailpipe is sucking in. Vacuum gauge flutters at idle, but within a 1 inch of vacuum range. Leakdown only 5% for each cylinder and compression gauge shows 150 Lb per cylinder, about 50K on shortblock. No smoking, all spark plugs look perfect, and otherwise runs great to redline. However, it too will stall or almost stall when coming to a stop after a hard run, then recovers to the idle speed. The symptoms MAY have been there since the rebuild, but I assumed it was the new cam's characteristics. The machine shop owner is now examining the spark plugs I pulled, and is puzzled why, if a valve issue, it isn't showing up on the leakdown test. Seems to be a very good question. Possible already have a recessed valve? Burnt valve? Valve guide too tight? Anything else I could check before having to pull the head? (A bit harder with a turbo)

[@TheVintageEngineer]

One thing you can do without pulling the head is measure how high the valve stems are with the followers removed. If you watched my follow up video you will see that mine where 0.080, 0.070, 0.050, and 0.050” recessed respectively. You would have to to rig something up to make your measurements precise. Like a couple of tall parallel bars across the head and using a depth micrometer. Be a relative test as there as I have no idea of a stem height spec. Another thing is having someone with a scope (oscilloscope) put a pressure transducer in the exhaust. This would show the pressure pulses and if one had an issue and you could tell which cylinder if you had the waveform synced to a spark plug wire. Did it only happen recently or been around since rebuild?

[@johnmcmullen456]

@@TheVintageEngineer Thanks for info, worth a shot before pulling head. At this point I don't know which cylinder has problem. This issue may have started at time of installing the head. Just recently I learned of and tried the dollar bill exhaust check, as well as vacuum gauge testing, when someone with a similar car and camshaft brought to my attention that the idle should be a lot smoother.

[@everardoquintana1097]

Very complete info, thanks for sharing

[@Everything817]

Great info brother. Out of curiosity, what does the machine shop do to fix a head with recessed seats?

[@TheVintageEngineer]

Seems likely they don’t. Seats get recessed and the walls between the valves get thinned out and usually crack between. My head got magnaflux and found cracks in them. But I did get a reman head for pretty cheap from Allied Motor Parts near Atlanta Ga. $330 at the time+ $50 core. Return shipping prepaid.

[@danieltinoco8569]

This is happening to my ranger bro I figured it was recessed valves too , I plan to replace all the valves and valve seals. it's a good truck!

[@TheVintageEngineer]

Might want to look at getting one that’s already rebuilt. Took mine to machine shop and it had tons of micro cracks. Guy said they almost always crack because the material has been thinned out. I got a head from allied motor in Atlanta ga for $330 shipped.

[@elenalyonsfan]

After watching this video I believe this might be an issue with mine. I've got a 98 2.5 automatic 409,000 miles that I've been battling idle issues upon stopping. The engine is properly tuned and I've had every test done possible except a leak down test. Which I'm now thinking of having done. Never a code, no misfires. Compression test done twice yielded perfect results. Did a smoke test and just like yours only the idle air bleed cap leaked which is normal. Fuel pressure is about the same now with a new pump. Vacuum is the same as yours. Even went as far as to swapping everything in egr system and ignition system to original Ford replacement parts. I know the egr system kills these little motors. Have had a lot of bad luck with fuel pumps as you can't get a good quality one. Mine drives perfect, normal power stock. It does not like to idle especially with the a/c on. It has the hardest time coming back to idle from a highway speed. The engine was replaced with a good used one at 228,000 miles and now the used motor probably has the same amount of miles. Did you end up breaking any exhaust bolts/studs when removing the exhaust manifold?

[@TheVintageEngineer]

A few years prior I had a crack in my cat converter that I had to remove the pipe to weld it up. I broke both bolts going into the manifold flange. Ended up getting a tubular style manifold from a 96-97 model and had to add an o2 bung on the cat pipe after the flange. When swapped manifolds, instead of using the taped holes on the flange I set it up to have the bolts go through and secured with a nut so a broken bolt wouldn’t be an issue. Older tube manifold had bigger holes so I could use original size bolts to do this. Never had an issue with the manifold to head ones.

[@elenalyonsfan]

@@TheVintageEngineer Mine starting shutting off randomly again this weekend after replacing the fuel pump a week ago along with the fuel tank being cleaned as well. It would run 100% fine and drive fine but randomly cut off when going up an incline or coming down an incline. Almost as if out of fuel but had a 1/4 tank reading and only been 260 miles on a tank. I couldn't even drive it home it was cutting off so frequently. You could sit there and rev it up or idle all day long but just only when actually driving it would it cut off. Did you ultimately find out your head was damaged through the leak down test or just by physically removing it and looking at it? I was told the leak down test would tell me if a valve was leaking in the head. I'd like to learn more about the dollar bill on the tailpipe trick too.

[@TheVintageEngineer]

@@elenalyonsfan hmm those symptoms sound different. If you don’t have any issues after a free rev I don’t think you have this issue. If it cuts off going up a hill, I’m thinking fuel or ignition.

[@elenalyonsfan]

@@TheVintageEngineer After swapping out the fuel pump because of low pressure I'm still having similar symptoms. It kept stalling out randomly and wouldn't idle very good. I had to have it towed and haven't figured it out yet. I verified the fuel system is now working except for the gauge. I was told to try the leak down test. I plan on doing a compression test and if it's good a leak down test. I think mine has had it. Did get a continuous code for P0303 but service manual said it could have been because it ran out of gas.

[@TheVintageEngineer]

@@elenalyonsfan p0303 most likely wouldn’t show up with it running out of gas. You would most likely see P0171 for being a lean mixture. But even that probably won’t set in that short of time.

[@isaiahwelch8066]

Honestly, my diagnosis isn't in the valve train, but the timing belt. I've had this issue myself, especially with a running rough issue, where the engine will just cut out for no reason -- come to find out, the timing belt, being rubber, stretched, and the timing jumped 180°. It could also be that a timing belt on a 2.3 or 2.5 is worn, and doesn't show the issue when cold, but rather, when it's hot. Additionally, this issue of coming to a stop at a red light, and having a rough idle/dies symptom, was also symptomatic in my ex's 1999 Cavalier a few years ago. The solution there was also a timing chain that was over spec by 13,000 miles. This would also be why you have good compression/leakdown tests, but the rough idle persists. The actual problem is that as the timing belt on a 2.3/2.5 stretches, the ECM either advances or retards your timing to maintain running the engine, getting to the point that at certain RPMs, like idle, the timing is then all out-of-whack. And just saying, most Ranger guys never look at the timing belt, even though it is a wear item, because it isn't a chain, but rather, a belt. What I would do is check the belt first, for cracks, wear, etc. If it checks out, loosen the tensioner spring and the tensioner mounting bolt, let everything adjust, then tighten it up, and see if it runs properly.

[@TheVintageEngineer]

It was the valves, replacement fixed it. Can’t recall if I said in the video or not but I checked the timing belt. Everything was lined up and nothing was off a tooth.

[@DuttonWebb]

If it were the timing belt, it would be all 4 though right? I have cyl1 missfiring at idle only. All spark and fuel components replaced. Good compression on all 4 as well. Don't get me wrong, I'm replacing the timing belt as well even after I get my valve seats replaced and head planed.

[@isaiahwelch8066]

@@DuttonWebb : Actually, a misfire on 1 cylinder points to an issue with the ignition system. My feeling is that on a 2.3/2.5, it is probably the ignition coils, or a control wire that is corroded. Corrosion is the bane of an electronic component's existence, as it increases resistance, which impedes conductivity. And on a 2.3/2.5, the ignition coils are right above the exhaust manifold -- which is a major source of heat. Which, in that case, means that your primary coil could have a degraded flow to a specific cylinder.

[@whiteyriley3179]

I think I have the same problem with my 2.3 did a compression test and #3 has 35psi Checked everything else Truck runs good at 3-4000rmp but lately wen I put it in gear it dies so I’ll take the head off and see what’s going on Thanks for the video!

[@TheVintageEngineer]

Whitey Ruf since you get a bad cylinder with a compression test I would do a leak down test to be sure. Listen to where the air is leaking to (exhaust, intake, crankcase, etc)

[@whiteyriley3179]

Ya I only turned it over four or five times But I’ve read some people do it with the throttle wide open dose that make a difference? And I left it on the 4th cylinder overnight and the next day it was down to 100 psi so I guess I should do a better job of tightening it in there I just did it hand tight but I could use a wrench next time What’s a sufficient time for a leak down test?

[@TheVintageEngineer]

Whitey Ruf pressure will drop as soon as the engine stops turning as there is some slight leakage on all motors around the piston rings. The reason it shows pressure on the gauge when you stop is the check valve. That bleed off of pressure you saw overnight is the pressure leaking at either the gauge or check valve. Ford says to perform the compression test with a warm engine and with the throttle open and it will make the numbers higher, but 35 psi is too low to me for a cold engine no throttle opened. To do a leak down test you need to set the engine to too dead center for that cylinder and just put compressed air into it, you can use the hose that the compression tester uses to do this. When air is going through you should have a good indication of where it’s leaking out. I don’t have a good video of this but there are plenty out there.

[@whiteyriley3179]

Anthony Shelton I’ll do that and listen for a leak I did a compression test on that cylinder again today and got it up to 85 with the throttle open I fixed a bunch of vacuum leaks too and it didn’t help much I put a bill on the end of the exhaust pipe and it didn’t suck it in or seam to have any vacuum there But thanks so much for the info fella!

[@michaelshirdon4267]

About to start diagnosing similar symptoms. No shop wants to touch it. All said get an engine or another vehocle.

[@ElitePainting_EpoxyCoatings]

Thanks for informative video!! My 2003 Ford Ranger Edge is currently in the shop for similar symptoms. We feel it's a recessed valve seat issue. Mine loses power and sputters during uphill acceleration, when it does that the CEL flashes then stays on and registers a misfire code. (Codes started with Cylinders 4 and 6 then jumped to 3)... Currently awaiting a leak down test.

[@TheVintageEngineer]

Robert Lance you got a 3.0? The TSB was for 02-06 3.0L

[@gordonpotts753]

Great video. Saved my ass.

[@michaelshirdon4267]

vehicle. Thank You for sharing your findings and procedures. Great job! Would like to know what the outcome was. 🤔

[@TheVintageEngineer]

Reman head fixed it. Here is follow up video: FOLLOWUP: Ford Ranger 2.3 2.5 Stalls After Rev Rough Idle Fix (Recessed Valve Seats) kzbin.info/www/bejne/mJq9n51nbpaLg7M

[@edwinflood6184]

My 1998 2.5 Ranger has the same problems, lm ready to pull the head! Thanks!

[@phillipolivas8182]

Good Job very helpful.

[@MidwestBenji]

I just dropped a new head into mine, it’s doing this to me, I’m fkin livid. I was hoping it would be something like a clogged cat, but this here is most definitely pointing me towards a defective head

[@toddcoates5584]

Got a good one for you,I replaced witha reman cyl head .all new parts,same issue? I'll let you know .danger ranger

[@gavingizowski7339]

Great video man, I got all the same issues, intermittent stalling and rough low idle coming up to lights. However, it also does this on start up intermittently, also surges/stutters at idle until partially warmed up. Did you happen to have those issue as well prior to your fix? Thanks in advance. Great video.

[@TheVintageEngineer]

Kinda. A good way to tell is to do the dollar bill/receipt trick on the exhaust pipe when it’s acting up. Hold the bill flat against your hand and hold it up to the exhaust about an 1” away. If it periodically tries to suck the bill or receipt into the exhaust instead of always pushing on it, then you’ve got a valve issue

[@ThatGuyIGuess]

My 98 2.5 l ranger, I had to pull the head cause it had what felt like a dead cylinder. Also been burning coolant since I bought it, so i knew the head gasket was done. I had recessed valves, clogged coolant port, gasket was letting coolant seep through plus it blew between cylinder 3 and 4. Probably should have taken care of it a long time ago.

[@TheVintageEngineer]

Mine was going on for a year and half. These dang motors are so resilient it makes it easy to push repairs back.

[@DuttonWebb]

I know this is a terrible idea, but could you cut away material around the valve seat to improve flow?

[@terrydurnil8087]

Just quick thought, Im not sure if someone may have mentioned this already, but wouldnt a basic CT readings be low to indicate the recess?

[@terrydurnil8087]

lol nevermind, you addressed it toward end of video

[@ethandfortune]

Thanks for the great information. The vehicle I'm diagnosing is having the exact same issues. My boss watched this video and still doesn't believe what I've showed him or this video. So I said fuck this and tightened the the throttle stop screw out to put the idle way fucking high. Probably 1200 1300 rpm owell, Issue is still present obviously cause of the valve seats. But it doesn't die when it starts stumbling then smooths back out only a temporary bandage for something that needs open heart surgery. But then I quit my job because we got in an argument about something else. Gotta work as a team not compete on who's right or wrong.

[@TheVintageEngineer]

Customer will probably be back asking why a P0507 error code is lighting up the dash now because the idle is so high. 😁

[@bacornish]

Same issue 86 2.3 #3 cyl Gonna try new exaust valves and see what happens

[@iwouldrathernot4274]

Wow my truck has been having this issue lately. It wouldnt get bad enough to stall but every now and then it would start idling like crap at a stop light or coasting to a stop. I have a lean code p0171 and its been almost impossible to track down. I kinda think Ive found it at the intake manifold which after 230k on what I suspect is original gaskets, I cant be mad. But I thought the issue is one in the same - lean condition causing rough idle sometimes. I guess a manifold gasket set is cheap and I can change my plugs, wires and valve cover gasket while I have it off just to see if it fixes it but my truck seems to have the same issues as described in the video. Non driving, of I rev the truck to around 3000rpm really quick and let off, it will start to misfire hard. It can usually catch itself and almost always stops when I pat the throttle. It doesnt run bad at those RPMs while driving though. Last weekend I was pulling a heavy enough trailer through the hills and was sometimes in 3rd pushing 3500 or so and it ran fine. Im going to try the manifold gaskets and see if it kills the issue. Worst case I guess is I get another set when I order the head gasket kit. I will update after. Also to note Im a technician and its stumped me for quite a while.

[@TheVintageEngineer]

Got a scan tool? I would look at short term and long term fuel trims for high positives ( +15 ) at idle when truck has switch to closed loop fuel system status. If high at idle, try bringing RPMs up to 2500-3000 and see if your SHort terms drop as the rpm increases. That will be a good indicator if you have a vacuum leak from your gaskets. Mine as I recall didn’t really ever have fuel trims out of norm.

[@iwouldrathernot4274]

@@TheVintageEngineer I had an autel and I monitored all of my fuel trims, o2 function, tested vacuum, Egr ability and function, I even pulled the red and green vacuum lines that run behind the head to the intake and egr off and tested them with air and water because there was a very slight change when I sprayed over them. I just had the issues come to light tonight, and I think my problem is a double whammy and the vacuum leak was leading me off course. I can hit the number 4 intake runner with spray and the idle has about a 60/40 chance of responding. It wasnt consistent, but I decided to try the dollar bill trick and sure enough its sucking the dollar bill back into the pipe when it misses. My vacuum gauge was very steady but would fluctuate a few inhg, as would the engine idle. Im sure my truck does have a vacuum leak, but I dont think its the only issue I have here.

[@TheVintageEngineer]

@@iwouldrathernot4274 have you looked at mode 6 misfire data yet? The misfire percentages correlated with how much each valve was sunken in. If you got a bore scope with a right angle lens attachment, I bet you can get it in there at TDC and confirm if valves are sunk or not. I have a follow up video showing what they should look like. They are actually proud of the surrounding head area by about 0.050”

[@jamesstinnett1734]

I have an issue that relates to yours, for the guys who are trying to install a new oil pump on these motors, they put a new pump in then the silly thing wont start,,, well gezus h !!, the new oil pump has more pressure than neededand pumps up all the lash adjusters, to the point that all valves are open all the time, = 0 compression.. ok so old pump goes back in stupid thing starts up, your diagram is the exact cause of this, all the seats are worn, and all valves are to tall with the new pump , fix== rebuild head, this sucks new or reman is 600 ish plus the new tty bolts and gaskets and gotta do this before the pump can be addressed, WELL IMAGINE THAT, JUST MY LUCK, now then you got the idle rattle that goes along with it, most of time the rattle will kina go away as you load the valveson a slow or excessive accelerate, found the rattle!, the to tall valves have all the springs at a weakened condition and the tension on the cam is not enough to stop the cam from rattleing back and forth, wek springs dont push up enuff to off set the lash ajusters,, AGAIN, rebuild head, OMG! can not catch a break, i discovered this issue about 5 years ago on my truck and you are the first person ive found that described thiese issues like this , and you went to the valve train config , so i guess this makes 2 of us, thanks for the video.

[@TheVintageEngineer]

Dang you aren’t kidding on that price. In 2019 when I ordered my reman head from allied motor sports in Georgia it was $330. That included the camshaft in it. Now it’s over $600. Ridiculous

[@markysspotlight2472]

Thank you for this my friend, you just saved me a ton of money lol I'm gonna pull the head and have the machine shop take care of biz.

[@paigehoward7078]

My 98’ 2.5l is doing the same thing. I’m trying to figure out how to work on the truck myself, but half (more) of the components/terms I have no idea what is being talked about. Are you for hire?😂

[@NotSoGrandGarage]

I'm having some very similar issues with a reman engine that I just installed Its a 1990 8 plug.. no codes being thrown and no good way to see much of anything as far as the ECU is concerned. Reman longblock from the local parts house... idles fine cold... but misfires like crazy if the throttle is touched. Once it's warm... it runs great unless reved hard or driven hard... let off the throttle fast and it starts misfiring again.. then it will recover on its own. I've double and triple checked everything... ignition was all fresh on the other engine (new plugs on this one). It's not dropping spark (tested with a spark tester on every plug).. tried injectors... cps is new... o2 is new.... ect sensor is new. o2 and cps were original so they were changed while the engine was out. ect sensor was changed tonight chasing this problem. o2 sensor has been cleaned and tested. I'm pulling my hair out. Tonight, I pulled the exhaust at the manifold and when it starts misfiring, it has a tap coming from the exhaust (which I've heard before in engines with bad valve guides). Is it possible that I've got this issue on a reman? The original engine ran great and everything else was swapped over to this long block. Every plug has been cleaned and double checked... every vac. connection has been double checked... grasping at straws at this point because I wouldnt think a reman long block would have this issue... but maybe? What are your thoughts?

[@TheVintageEngineer]

It’s possible the reman shop didn’t set the valve seats at the right height. Try the dollar bill/receipt against the exhaust test

[@NotSoGrandGarage]

@@TheVintageEngineer just did. It seems to suck the paper into the exhaust when it's misfiring. So I'm assuming an exhaust valve or 3 are hanging open...

[@TheVintageEngineer]

@@NotSoGrandGarage Sounds like it.

[@dogsandwich77]

Same exact thing is happening to mine. '99 Ranger 2.5 Remanufactured engine from (go ahead and laugh), AutoZone. All the same symptoms, does ok when the engine has been drivin a few block, which turned into miles, just got worse and worse. The engine did just fine for the first 20,000 miles. I put a vacuum gauge inside the cab, and one day I noticed it was bouncing like crazy when I started it up. That was strike one. By now, it had codes all the time for cylinder 3 amd cylinder 4 misfires. Catalytic converters were coming apart too. Strike two was the F- it got on it's (cold) compression test. Number from that aren't even worth mentioning. Final straw and confirmation for me to stop thinking about what it could be besides the valve seats, was when I took the intake off, to look under the valve cover, popped out the follower for cylinder 3's intake and the HLA was pumped up and extended all the way up. I couldn't even compress it without a vise to get it back in. Only thing left for me to do is pull the head, and spend the money, again. Then push this thing off a cliff and get on with my life hahah The amazing thing is that its still drivable. I just have to let warm up for like 15 minutes and drive with 3 feet running stop signs until i get in the freeway. After that, it's ok, other than getting 14 mpg and exhaust that smells like a federal crime. Thank god I kept my '89 f150. That 300 straight six is indestructible. Sorry for the long comment, just trying to relate, let ya know that, yeah, the head is fooked. The quicker I accepted that, the less I constantly wasted time and money trying to figure it out. Cause mine will suck a dollar right outta your hand into the exhaust pipe and give back incorrect change. Chain store remanufactured engines are garbage.

[@NotSoGrandGarage]

@dogsandwich77 thos one came from oreillys but they all use the same builder. All the parts house engines have the same part number and same warranty. Waiting to hear back what they are going to do. Hopefully send me a cylinder head... and warranty covers labor so we'll see.

[@eddyschonfield7298]

I put a rebuilt head on 1990 2.3 and it's doing the same on mine i think they didn't grind the valve stims right witch would kinda be the same

[@josedejesusgarciagutierrez1579]

Actually I have the same issue in my ranger 01' 2.5 I brought it to my mechanic, that ticking noise started last year but very quiet, but the last week it make it worst

[@notfamousprepper7369]

Great video! Did the new head fix your issue?

[@TheVintageEngineer]

Yes, purrs like a kitten. Can rev the hell out of it and it settles down nicely without a hick-up. Was weird driving it the first couple of weeks because I was so used to having one foot on the brake and one feathering the gas at stop lights. After I got the new head I figured out that the valves don’t sit flush new but about 0.050” proud. So my valves sunk like 0.080”, 0.070”, 0.050”, and 0.050”

[@notfamousprepper7369]

Awesome glad to hear it! Any theories on what caused this issue in first place? Low oil pressure on hydrolic lifters or worn out lifters? Or high chamber temps causing the iron head to soften when valves closing against it?

[@TheVintageEngineer]

Good question. I’m leaning towards high cylinder head temps. My coolant has been rusty nastiest for years. Since I was replacing the head a I ran a product called Thermocure through it for a couple of weeks and flushed it out. It removes rust and I pulled the water pump to find bare clean metal in the block after using it. So maybe the cooling efficiency was low due to rust buildup. Pressure tested the exhaust and it was fine so I don’t believe it was due to a restrictive cat. It could also just be soft valve seats, not as soft as the 3.0 rangers that had the TSB but softer than normal where it didn’t appear until really high millage. Seems to be more common on the 98-2001 1/2 2.5L than the pre-98 2.3s.

[@jamesbell1764]

Awesome vid man! I have been turning wrench’s for most of my life, I have owned 4 rangers all 93 or 94’s, never had the high rev and die issues. I have chased and replaced in my current ranger the entire time I have owned it, so I’m guilty , like the guys you talked about I. The vid. The truck finally runs runs pretty darn good except if I rev high and let off it dies, runs rich at idle, falls on face up hills. I 100 percent believe this to be my issue and will be pulling the head and having head work done. Good job and thank you!

[@TheVintageEngineer]

James Bell before pulling the head I would at least try the dollar bill/receipt test over the tail pipe when it’s running rough (if it tries to suck back in this is a good sign of the issue). I would just hate for you to pull a head and it not be the issue. You get any misfire pending codes?

[@toddski6971]

My 2000 Ranger just hit 265K.... I have the exact issue when you get off the throttle fast...if I ease the throttle back to idle no stumbling at all.... I have no codes at all but I was going to check for vacuum leak because my LTFT is running around 18% at idle but truck runs fine. Your video is brilliant! How did your engine run after head rebuild or did you have to replace head?

[@TheVintageEngineer]

Runs great after buying rebuilt head. I would look at that LTFT first before anything. My LTFT where damn near 0 before the swap.

[@toddski6971]

@@TheVintageEngineer Thanks for quick reply...I will continue to check LTFT issue. I will probably smoke test the intake manifold, Glad to hear new head has your truck running like new.

[@TheVintageEngineer]

@@toddski6971 when you smoke test don’t worry about smoke coming out of idle air valve vent as it’s normal.

[@joeycmore]

Thanks for such an in-depth video. I'm not much of a tech, so learned plenty. Do you think this issue is possible for a '92 3L?

[@TheVintageEngineer]

The did have a similar issue on like 2002-04 model 3.0L engines but I don’t think any of the 3.0s had issues that far back.

[@joeycmore]

@@TheVintageEngineer Great! Thank you very much for taking your time to answer... Now I just have to run the gammet on all the other typical fixes. Cheers.

[@tomforletta7197]

Great video thanks! Question for you though. The symptoms on my 2000 2.5L are absolutely identical. Good compression on all 4 cylinders. It also fails the dollar bill test. I removed the head and unfortunately none of the valves appear to be recessed, all sit a little proud. I have a lot of carbon build up on #1 and some on #3. No smoke from exhaust though. Any thoughts?

[@tomforletta7197]

I should have added that I replaced the coils, wires. Plugs are also fairly new and in good shape.

[@TheVintageEngineer]

Can you measure how much proud they are? The reman I got was 0.050” proud. Also do the valves seal ok? Pour some water into the combustion chamber and see if it easily leaks out when the valves are closed.

[@TheVintageEngineer]

Also may want to see if the valves move freely in the guides. Could have been hanging up.

[@tomforletta7197]

@@TheVintageEngineer I wasn't able to measure it and thought about but then forgot to try the liquid test. We took it to a machine shop and he pointed out two micro cracks on the cylinders with the carbon. (1 & 4, I think I mistakenly said 1 & 3 earlier). I should have it back together in a few weeks. I'll update this with the results. Thanks again.

[@jeremywilson8101]

I've been trying to figure this problem out for 2 yrs. i just pulled the head thinking i had bad rings or valves damaged on cylinder 3 cuz i kept getting p0303. a year ago it would just skip slightly only cold and warm ran fine until winter then it would skip all the time at idel. so yea pulled head and mine are recessed pretty bad so i went to search for a vid on resurfacing the valves seats (cuz im getting light thru the exhaust valve closed) and found your vid so thanks i thought at first that's how they design the head lol can i just replace the valves and lap the seats or is the seats toast? what did you do as a fix on your head?

[@TheVintageEngineer]

Take a look at this video. Took it to machine shops and they said when the wear down like this they almost always crack between the valves because of it thinning out. Best is to replace head. kzbin.info/www/bejne/mJq9n51nbpaLg7M

[@toddski6971]

I have the exact same symptoms and issues and just recently started getting an intermittent P0302 code. My engine has 269K and I will be replacing the head shortly. I have a new head ready to go on. Can't wait to see what the old head looks like especially for the #2 cylinder... I will keep you all updated when it comes off.

[@user-tp3hg4se1s]

Mine was the power steering pump pulley seized up and very hard starting and running 🙄

[@jackb9199]

I have the same problem but I found i think it’s my EGR tube. I bought the part and taking it off was easy because it basically crumbled in my hands. The only problem now I have is that I broke the egr nut off the exhaust manifold. Now I need a new exhaust manifold. I was wondering if anyone knows if a 2.3 manifold will fit my 99 2.5z.

[@TheVintageEngineer]

Take a look at this thread I made some years back. I’m running a 1997 2.3 (header style) on my 2000 2.5. You can see the modifications I had to make. www.fordrangerforum.com/4-cylinder-tech/108087-exhaust-manifold-difference.html

[@davidrensi737]

Great info!

[@michaelhughes5521]

Sir I have a 94 2.3l ranger how do I fix what you explained?

[@TheVintageEngineer]

Rebuild or replace cylinder head

[@JP-kb4yi]

Do you do this repair for customers? If so where are you located?

[@TheVintageEngineer]

I usually don’t work on other peoples vehicles, well at least not this deep in the engine. Any mechanic should be able to do this for you. In the end, it will most likely be a head replacement because the valves get so recessed it thins the walls out between the valves and it will most likely have cracks.

[@JP-kb4yi]

@@TheVintageEngineer I understand. Thank you for making this video. You described exactly what my 01 Ranger is doing. We’ve been replacing parts and nothing has worked. Ironically my brother has a dream shop and the knowledge to make the repairs. When I showed him your video, he said he’s certain that’s what’s wrong and will do the dollar bill test tonight. Unfortunately he’s an over the road truck driver and only home 34hr MAX every 7 days. He’s already got more work then he can do and doesn’t want to add to the list. I’ll keep searching for a trustworthy reliable mechanic but if you change your mind let me know.

[@TheVintageEngineer]

@@JP-kb4yi yours a 2.5 engine? Reason I ask is because they switched to a different 2.3 dohc and engine in the middle of the year.

[@JP-kb4yi]

@@TheVintageEngineer idk. Where would I find that?

[@TheVintageEngineer]

@@JP-kb4yi look at your VIN number and see what the 8th digit is. Should be either C,D,V,U or E. C is the same engine as mine (2.5). 2.3 is a D. The V and U are 3.0 V6 and C is the 4.0 V6

[@trashman1694]

I got a 1994 2.3 with 332,000 miles and think this is my issue... probably a couple other issues as well haha

[@Alex102133]

Did you figure out what you're issue was? I have a 1997 2.3. Thanks

[@trashman1694]

@@Alex102133 Nah parked it for now. Been meaning to compression test it but been busy working lately and idk where i put compression tester at. Pretty sure the engine is about done, probably a bad head gasket mostly but i'm sure the rings and valves are about cooked as well

[@kamryn7496]

My 3.0 bent a exhaust valve in cylinder 4

[@stevenmickles7736]

Wow

[@aashanarana7906]

Hey man I just took of my heads . 99 3.0 ranger. They look way worse than yours. About 1/4 inch in depth all the exhaust valves were in on bank one

[@TheVintageEngineer]

The 3.0 was a well known issue. If I remember they put too soft of seats in the heads so they wore prematurely. They showed issues with even lower millage than the 4cyl engines

[@d.p.9005]

Lima 2.3