@CrazedPerformanceRepair this is top notch diagnosis and the kind of knowledge that can only be acquired through direct experience and critical thinking yet you are conveying it clearly via video. Excellent job. I'm still snoozing on getting these broken manifold bolts outta my wife's truck though lol.
@CrazedPerformanceRepair I got it done a few months ago. Now it's got random misfires in all cylinders mostly #4. Gonna do some tests this video should help.
Subscribed, going through this same issue with a four cylinder. 2006 tsx. Leak down test is next on my list. Compression good, new injectors, new plugs, new coils, coils and injectors get power so yea next is leak down test
Had a 5.3 silverado with a misfire and a ltft imbalance. Fuel was being pulled, but no code, just misfire. Buddy thought is was coil, vac leak. Misfire went away when I swapped a take off injector I had. Ltft kept removing fuel and started throwing code. I swapped his aftermarket maf sensor for oem. It was strange because the maf g/s was only off by maybe 5% or so.
P0300 code on my 3.8 Eclipse. New coils, plugs, maf ,map, injectors, fuel gauge...Checked crankangle sensor & cam sensor. It just stalls and dies at idle, randomly. Chemical tested for head gasket leak, no exhaust gas found in coolant. Thinking I have bad lifters as I have a wicked rattling noise that comes and goes, maybe causing a misfire.
How about checking across head (and perhaps lengthwise too) with straight edge and feeler guage prior to maching head? ( It would be intrresting to know the depth of the concave). Are you going to check the block for flatness too? J
Help please! If you find that your bolts were all very loose, not even finger tight. is there a chance that you can tighten them back? Would that pressurize the engine and unstick the lifter? Replaced sending unit &screen , helped but not the noise- after watching your videos I checked the bolts and they weren’t even finger tight. A few things happened that I feel caused this. Ran out of gas- I know- it was very stupid but I was in a hurry and well.. that will teach me! Bought a gas can- btw I was holding up highway traffic so let’s say I was panicking- Tried starting without enough gas in it. I was finally able to unstick faulty can Got enough gas to make it to the gas station, everything was fine, ran great like always- got back on the highway 5 miles down the road, the truck starts shaking- I immediately get off and pulled over. Sounds horrible but drives fine, drive it 10min to my house but then starts shifting hard- only in 2nd gear. Just curious if I could have multiple issues because of gas and if not pressurizing cause of manifold plate/ vlom.
I have a misfire p0301 and a reactivation control performance code p1411 on my gen 3 5.7 hemi. Im guessing the solenoid for the MDS system is stuck. Last oil change I used mobil 1 full synthetic high mileage for the first time instead of the non high mileage which is the manufacturer recommened oil. Im now curious if possibly the high mileage oil gummed up the solenoid. What do you think of the additives in the high mileage oil does it cause sludge? let me know. I'm thinking of trying a partial ATF flush as it is due for an oil change now. I was going to just add a quart of ATF run it for 15 minutes and drain it and refill with fresh oil and see how it behaves. If it doesnt resolve the misfire I'll have to pull the intake and replace the solenoids I figure i may as well do them all while I'm in there.
I thought the whole point of precision machining was...umm... precision. I know there are hollow ground chisels and plane blades (so you can sharpen them faster). But hollow ground heads and decks. That's wild.
Once I actually got it apart it turned out to be multiple badly leaking exhaust valves transfering air to each other from a really bad OEM valve job. Also had small gasket leak too. Valves seats where so bad I was concerned I wouldn't be able to fix it without replacing the seats. Did have to replace some valves though.
Hello. You made me very worried. I have a 1991 Pontiac Grand Prix, 3.1 V6 (LH0) engine. This engine used to run very smoothly, but now it vibrates slightly at idle. I checked everything, dynamic compression and it is 175 psi on all cylinders, perfectly even. I replaced the spark plugs, ignition cables, ignition coils, ignition module, engine controller, fuel injectors (new). My fuel pressure is correct. The only thing that deviates from the norm is the cylinder tightness test. I applied the pressure to 70 psi and during the test it dropped to 61 psi. There is a lot of noise coming from the crankcase. This air leakage into the crankcase is equal for all cylinders. The spark plugs have a white coating on the upper electrode, they are dry and not oily. I also noticed that a minimal amount of oil collects in the intake manifold. I replaced the PCV valve, but it didn't change anything. Could this large air leak into the crankcase cause the engine to shake? This shaking is very annoying because I can feel it on the steering wheel when I'm standing still, and it shouldn't be like that. The entire timing chain is also fitted with a new complete one. What else could I check? I am asking you for help. Regards. Adam from Poland
If its more of a vibration, the timing could be off. It could also be drive belt system related or even the harmonic balancer dampening rubber has slipped causing an imbalance.
@CrazedPerformanceRepair Thank you very much for your help. The pulley-vibration damper is in perfect condition. The timing chain and timing sprockets are new. Do I still need to check the hydraulic tappets? Could it be that the valves are not closing randomly? Could the engine suspension mount be the reason? I have a new pillow from Anchor, but maybe I should buy an original GM pillow? Will this 10% air leakage in the cylinders not cause such difficulties and vibrations of the entire engine?
@@supermolibden5037 most cylinder leak down testers need to be at 100psi for the test. Read the instructions and check again. But 10-15% past the rings is fairly normal. A bad engine mount can cause you to feel more orange and vibrations. But I am not sure what kind of vibration you are getting, high frequency low frequency etc. typically bad engine mounts allow you to feel more shake and a four-cylinder. That V6 is a really smooth running engine normally and even with bad mounts you typically can't feel it. So this is why I questioned the timing being off. Just because you have new timing components doesn't mean they were lined up correctly when installed. You would need to do a lab scope to verify whether the timing is good or not without having to take things apart. This requires hooking up to the camshaft position sensor and the crankshaft position sensor then overlaying them on a screen with a lab scope. Then you can compare it to a known good reading. As far as the pulley system goes, you could have an alternator with a bad winding for example. This would cause it to pull magnetically harder on one part of the rotation thus creating a high frequency vibration. You could also have something like a power steering pump with a bad vein that's stuck in position. This would cause a slightly lower vibration issue. You need to pull the belt off and run it with the belt off for a moment just to see if the vibration is gone. Don't run it long though has this stops your water pump from running.
@CrazedPerformanceRepair Thank you very much. The timing and wheels were checked, and for this purpose the cover of the front part of the timing was even removed and the correct setting was checked. I even checked the markings on the timing belt that was originally in this engine to see if the factory made a mistake in placing the marks on the timing gears in the new timing belt. . I have been working and repairing engines and automatic transmissions for 30 years. Of course, I do it for myself and not professionally. The vibrations I am writing about are rather hard or very hard operation of the engine at idle speed. As you wrote, this engine, when it worked very well, was very smooth and did not produce any vibrations. I am very interested in what the ignition advance angle is? There is DIS ignition that changes this angle depending on the engine operating conditions. Can it be assumed that the ignition advance angle for a warmed-up engine at idle speed will be advanced by 8 or 10 degrees? I don't have documentation for my Pontiac and I don't know where to get such accurate data. I only have the book "HAynes Repair" for Buick, Pontiac, Olds, LUmina, 1988-1991. Ps. I will also test the cylinders for leaks at 100 psi, but since you write that 10 to 15% of air leakage is normal, it will definitely be so.
@supermolibden5037 you say timing belt but unless it's the 3.4 dohc that engine has a chain. As far as ignition timing, that engine is fully computer controlled and tuned to be optimized from the factory. So unless you did some sort of performance upgrading like a cam or something it shouldn't need to be changed. You say it's a hard vibration? You mean it's a lower frequency like a cylinder that's misfiring? Those have 3 coil packs bolted to an ignition module. Each coil pack produces well over 80kv under correct operation as it's a waist spark system. Have you verified all coils function correctly? Also, since that coil and the wires run near other harnesses if you did a tune up replacing spark plug wires and layer them near the wrong harness somewhere it can cause interference to inputs on the PCM. This can cause the computer all sorts of control issues. This same concept applies to the alternator as well. Notice that the alternator is next to a big harness and the ignition. So if it has a bad diod or something it will also bleed interference. I've also seen these engines have wire harness issues because of a bad dog bone mount causing too much flex in the harness over time breaking the wires down. It's and old car so lots of possibilities. Good luck!
My engine only shakes after warming up. Can someone tell me what it might be? I know there are some smart people here. The vehicle barley moves when pressing the gas, smoke or steam coming out of the exhaust pipe, etc. The water pump went bad and I replaced it. I think I had a blown head gasket. I used gasket sealer and the smoke reduced almost completely but when I first turn the vehicle on a puff of smoke comes out. No check engine light. The temperature guage does not go up enough when my scan tool shows a much higher temperature. The engine is knocking. When I remove the upstream oxygen sensors I hear something like clunking or air quickly releasing from the exhaust valve when it shouldn't, on the side that shakes the most. I would really appreciate advice, suggestions, etc. Thank you.
Got it. I was thinking your explanation of the warped head was from maybe a previous rebuild or head surface job. Bad machining from the factory shouldn't happen in his day and age.....lol!
Hi I have a 1995 Subaru Impreza N/A with 1.8L ej18 4 cylinder boxer. I had weak power going uphill and faster than 60mph. Took it to a suggested shop. They test drove it and did dry compression test for $120 and 3 days of my time. I'm not impressed. #2 and #4 cylinders both read about 77 psi dry. They said "bad head gasket" but didnt give helpful tests to show that. I don't have any overheating or fluid losses. I want to be sure. Can a mechanic or myself confirm my valve timing is correct on that one side without doing more than spark plug removal and part of the timing cover? Is it possible for SOHC to have one head mis-timed?
It's only really possible if someone installed a belt wrong. For it to jump on its own without more issues isn't likely. Head gaskets are really common on those though.
To test the head gasket you need to do coolant pressure test. 15 or 16psi see what it said on the coolant cap. Observe pressure drop over 15min then 30 min 1hr. Also while you have pressure still on in the coolant system open all spark plugs use inspection cable camera inspect all inside the cylinders. If there is blown head gasket you will see green coolant sipping through
I can believe this channel doesn't have 10 million subscribers
Maaan thank you
Same here, This guy explains everything in detail and he goes in depth.
This channel is a hidden gem.
This channel is pure gold. Way underrated.
Thanks! Wish I had more time for more videos.
@CrazedPerformanceRepair this is top notch diagnosis and the kind of knowledge that can only be acquired through direct experience and critical thinking yet you are conveying it clearly via video. Excellent job. I'm still snoozing on getting these broken manifold bolts outta my wife's truck though lol.
@@kentdavies1988 break out the welder like I did in my video a while back. It works wonders.
@CrazedPerformanceRepair I got it done a few months ago. Now it's got random misfires in all cylinders mostly #4. Gonna do some tests this video should help.
Excellent diagnosis of migrating gasket failure.
Subscribed, going through this same issue with a four cylinder. 2006 tsx. Leak down test is next on my list. Compression good, new injectors, new plugs, new coils, coils and injectors get power so yea next is leak down test
Face mill. Great video. Looking forward to the next installment.
Great stuff 👍 thanks for sharing. ✌ GOD bless America 🇺🇲
Nice explanation!
Had a 5.3 silverado with a misfire and a ltft imbalance. Fuel was being pulled, but no code, just misfire. Buddy thought is was coil, vac leak. Misfire went away when I swapped a take off injector I had. Ltft kept removing fuel and started throwing code. I swapped his aftermarket maf sensor for oem. It was strange because the maf g/s was only off by maybe 5% or so.
P0300 code on my 3.8 Eclipse.
New coils, plugs, maf ,map, injectors, fuel gauge...Checked crankangle sensor & cam sensor.
It just stalls and dies at idle, randomly.
Chemical tested for head gasket leak, no exhaust gas found in coolant. Thinking I have bad lifters as I have a wicked rattling noise that comes and goes, maybe causing a misfire.
Have you cleaned the throttle body, mass air flow, and checked PCV valve? I had the same issue and this solved it.
@@ChristianRachford-zl5tq finally smoke tested the engine...
I had a massive leak on the power brake booster line.
How about checking across head (and perhaps lengthwise too) with straight edge and feeler guage prior to maching head? ( It would be intrresting to know the depth of the concave).
Are you going to check the block for flatness too?
J
Help please!
If you find that your bolts were all very loose, not even finger tight. is there a chance that you can tighten them back? Would that pressurize the engine and unstick the lifter? Replaced sending unit &screen , helped but not the noise- after watching your videos I checked the bolts and they weren’t even finger tight.
A few things happened that I feel caused this.
Ran out of gas- I know- it was very stupid but I was in a hurry and well.. that will teach me!
Bought a gas can- btw I was holding up highway traffic so let’s say I was panicking-
Tried starting without enough gas in it.
I was finally able to unstick faulty can
Got enough gas to make it to the gas station, everything was fine, ran great like always-
got back on the highway 5 miles down the road, the truck starts shaking- I immediately get off and pulled over. Sounds horrible but drives fine, drive it 10min to my house but then starts shifting hard- only in 2nd gear. Just curious if I could have multiple issues because of gas and if not pressurizing cause of manifold plate/ vlom.
I have a misfire p0301 and a reactivation control performance code p1411 on my gen 3 5.7 hemi. Im guessing the solenoid for the MDS system is stuck. Last oil change I used mobil 1 full synthetic high mileage for the first time instead of the non high mileage which is the manufacturer recommened oil. Im now curious if possibly the high mileage oil gummed up the solenoid. What do you think of the additives in the high mileage oil does it cause sludge? let me know. I'm thinking of trying a partial ATF flush as it is due for an oil change now. I was going to just add a quart of ATF run it for 15 minutes and drain it and refill with fresh oil and see how it behaves. If it doesnt resolve the misfire I'll have to pull the intake and replace the solenoids I figure i may as well do them all while I'm in there.
I thought the whole point of precision machining was...umm... precision. I know there are hollow ground chisels and plane blades (so you can sharpen them faster). But hollow ground heads and decks. That's wild.
Once I actually got it apart it turned out to be multiple badly leaking exhaust valves transfering air to each other from a really bad OEM valve job. Also had small gasket leak too. Valves seats where so bad I was concerned I wouldn't be able to fix it without replacing the seats. Did have to replace some valves though.
Hello. You made me very worried. I have a 1991 Pontiac Grand Prix, 3.1 V6 (LH0) engine. This engine used to run very smoothly, but now it vibrates slightly at idle. I checked everything, dynamic compression and it is 175 psi on all cylinders, perfectly even. I replaced the spark plugs, ignition cables, ignition coils, ignition module, engine controller, fuel injectors (new). My fuel pressure is correct. The only thing that deviates from the norm is the cylinder tightness test. I applied the pressure to 70 psi and during the test it dropped to 61 psi. There is a lot of noise coming from the crankcase. This air leakage into the crankcase is equal for all cylinders. The spark plugs have a white coating on the upper electrode, they are dry and not oily. I also noticed that a minimal amount of oil collects in the intake manifold. I replaced the PCV valve, but it didn't change anything. Could this large air leak into the crankcase cause the engine to shake? This shaking is very annoying because I can feel it on the steering wheel when I'm standing still, and it shouldn't be like that. The entire timing chain is also fitted with a new complete one. What else could I check? I am asking you for help. Regards. Adam from Poland
If its more of a vibration, the timing could be off. It could also be drive belt system related or even the harmonic balancer dampening rubber has slipped causing an imbalance.
@CrazedPerformanceRepair Thank you very much for your help. The pulley-vibration damper is in perfect condition. The timing chain and timing sprockets are new. Do I still need to check the hydraulic tappets? Could it be that the valves are not closing randomly? Could the engine suspension mount be the reason? I have a new pillow from Anchor, but maybe I should buy an original GM pillow? Will this 10% air leakage in the cylinders not cause such difficulties and vibrations of the entire engine?
@@supermolibden5037 most cylinder leak down testers need to be at 100psi for the test. Read the instructions and check again. But 10-15% past the rings is fairly normal.
A bad engine mount can cause you to feel more orange and vibrations. But I am not sure what kind of vibration you are getting, high frequency low frequency etc. typically bad engine mounts allow you to feel more shake and a four-cylinder. That V6 is a really smooth running engine normally and even with bad mounts you typically can't feel it. So this is why I questioned the timing being off. Just because you have new timing components doesn't mean they were lined up correctly when installed. You would need to do a lab scope to verify whether the timing is good or not without having to take things apart. This requires hooking up to the camshaft position sensor and the crankshaft position sensor then overlaying them on a screen with a lab scope. Then you can compare it to a known good reading. As far as the pulley system goes, you could have an alternator with a bad winding for example. This would cause it to pull magnetically harder on one part of the rotation thus creating a high frequency vibration. You could also have something like a power steering pump with a bad vein that's stuck in position. This would cause a slightly lower vibration issue. You need to pull the belt off and run it with the belt off for a moment just to see if the vibration is gone. Don't run it long though has this stops your water pump from running.
@CrazedPerformanceRepair Thank you very much. The timing and wheels were checked, and for this purpose the cover of the front part of the timing was even removed and the correct setting was checked. I even checked the markings on the timing belt that was originally in this engine to see if the factory made a mistake in placing the marks on the timing gears in the new timing belt. . I have been working and repairing engines and automatic transmissions for 30 years. Of course, I do it for myself and not professionally. The vibrations I am writing about are rather hard or very hard operation of the engine at idle speed. As you wrote, this engine, when it worked very well, was very smooth and did not produce any vibrations. I am very interested in what the ignition advance angle is? There is DIS ignition that changes this angle depending on the engine operating conditions. Can it be assumed that the ignition advance angle for a warmed-up engine at idle speed will be advanced by 8 or 10 degrees? I don't have documentation for my Pontiac and I don't know where to get such accurate data. I only have the book "HAynes Repair" for Buick, Pontiac, Olds, LUmina, 1988-1991. Ps. I will also test the cylinders for leaks at 100 psi, but since you write that 10 to 15% of air leakage is normal, it will definitely be so.
@supermolibden5037 you say timing belt but unless it's the 3.4 dohc that engine has a chain.
As far as ignition timing, that engine is fully computer controlled and tuned to be optimized from the factory. So unless you did some sort of performance upgrading like a cam or something it shouldn't need to be changed. You say it's a hard vibration? You mean it's a lower frequency like a cylinder that's misfiring? Those have 3 coil packs bolted to an ignition module. Each coil pack produces well over 80kv under correct operation as it's a waist spark system. Have you verified all coils function correctly?
Also, since that coil and the wires run near other harnesses if you did a tune up replacing spark plug wires and layer them near the wrong harness somewhere it can cause interference to inputs on the PCM. This can cause the computer all sorts of control issues. This same concept applies to the alternator as well. Notice that the alternator is next to a big harness and the ignition. So if it has a bad diod or something it will also bleed interference.
I've also seen these engines have wire harness issues because of a bad dog bone mount causing too much flex in the harness over time breaking the wires down.
It's and old car so lots of possibilities. Good luck!
My engine only shakes after warming up. Can someone tell me what it might be? I know there are some smart people here. The vehicle barley moves when pressing the gas, smoke or steam coming out of the exhaust pipe, etc. The water pump went bad and I replaced it. I think I had a blown head gasket. I used gasket sealer and the smoke reduced almost completely but when I first turn the vehicle on a puff of smoke comes out. No check engine light. The temperature guage does not go up enough when my scan tool shows a much higher temperature. The engine is knocking. When I remove the upstream oxygen sensors I hear something like clunking or air quickly releasing from the exhaust valve when it shouldn't, on the side that shakes the most. I would really appreciate advice, suggestions, etc. Thank you.
Wouldnt you have to overheat the motor to warp the head to that extreme?
No, this was never overheated. I found out is was more than just a head gasket issue. As explained at end it was also cut bad from factory.
Got it. I was thinking your explanation of the warped head was from maybe a previous rebuild or head surface job. Bad machining from the factory shouldn't happen in his day and age.....lol!
Hi I have a 1995 Subaru Impreza N/A with 1.8L ej18 4 cylinder boxer. I had weak power going uphill and faster than 60mph. Took it to a suggested shop. They test drove it and did dry compression test for $120 and 3 days of my time. I'm not impressed. #2 and #4 cylinders both read about 77 psi dry. They said "bad head gasket" but didnt give helpful tests to show that. I don't have any overheating or fluid losses. I want to be sure.
Can a mechanic or myself confirm my valve timing is correct on that one side without doing more than spark plug removal and part of the timing cover? Is it possible for SOHC to have one head mis-timed?
It's only really possible if someone installed a belt wrong. For it to jump on its own without more issues isn't likely. Head gaskets are really common on those though.
To test the head gasket you need to do coolant pressure test. 15 or 16psi see what it said on the coolant cap. Observe pressure drop over 15min then 30 min 1hr. Also while you have pressure still on in the coolant system open all spark plugs use inspection cable camera inspect all inside the cylinders. If there is blown head gasket you will see green coolant sipping through