Mk3 supra 2jzget knocking after rebuild

mk3turbo

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Ive been searching and diagnosing my supra’s issue for quite some time now, see if you guys can point me to the right direction. I got my block back from rebuild, Cp pistons 10:1 .020 over, stock rods, standard rod bearing, stock head, arp studs. 1.5mm cometic hg. 2jzge head got new valve seals put in. I got everyting put together and it fired up. When it idles and rev up, no knocking or tapping noise, but when you put it in gear and go, there a tapping, knocking sound coming from the engine bay. I put the car on jack stands, put it in gear, there is no tapping, knocking noise by doing that. I dont think its a rod knock. You can hear it tapping from low rpm all the way to redline. As the rpm rise up it taps faster with the rpm. I drove the car about 2,000 miles now, the knocking, tapping noise stayed the same, hasnt got any louder, no hesitations. I check the valve clearance and they are all within toyota’s spec. Compression is 200-210psi across the board. Its got the older style driftmotion flywheel, old school rps 6 puck clutch kit. I also put a new head on and the knocking is still there. I took off the serpentine belt and drove it, knocking is still present. Torque the crank pulley bolt to 239ft tq, knocking still there, wasn't torque to spec at first. Now whats left is taking off the trans to inspect the flywheel, clutch and pressure plate, throw out bearing. And last its the bottom end.

Any ideas what this could be.

video supra taking off


Is this too much play for cp piston .020 over, 10.1 compression, 200psi-210psi across the board on warm compression test.
 
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A70nut

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Ive been searching and diagnosing my supra’s issue for quite some time now, see if you guys can point me to the right direction. I got my block back from rebuild, Cp pistons 10:1 .020 over, stock rods, standard rod bearing, stock head, arp studs. 1.5mm cometic hg. 2jzge head got new valve seals put in. I got everyting put together and it fired up. When it idles and rev up, no knocking or tapping noise, but when you put it in gear and go, there a tapping, knocking sound coming from the engine bay. I put the car on jack stands, put it in gear, there is no tapping, knocking noise by doing that. I dont think its a rod knock. You can hear it tapping from low rpm all the way to redline. As the rpm rise up it taps faster with the rpm. I drove the car about 2,000 miles now, the knocking, tapping noise stayed the same, hasnt got any louder, no hesitations. I check the valve clearance and they are all within toyota’s spec. Compression is 200-210psi across the board. Its got the older style driftmotion flywheel, old school rps 6 puck clutch kit. I also put a new head on and the knocking is still there. I took off the serpentine belt and drove it, knocking is still present. Torque the crank pulley bolt to 239ft tq, knocking still there, wasn't torque to spec at first. Now whats left is taking off the trans to inspect the flywheel, clutch and pressure plate, throw out bearing. And last its the bottom end.

Any ideas what this could be.

video supra taking off


Is this too much play for cp piston .020 over, 10.1 compression, 200psi-210psi across the board on warm compression test.
Does it make the sound with the clutch pushed in in neutral? I noticed you said it didnt happen with the car jacked up, did you have only the rear wheels jacked up? Does the knocking correspond more directly with engine speed or transmission speed?
 
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mk3turbo

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Does it make the sound with the clutch pushed in in neutral? I noticed you said it didnt happen with the car jacked up, did you have only the rear wheels jacked up? Does the knocking correspond more directly with engine speed or transmission speed?
No it doesn't make that sound in neutral with the clutch press in. This clutch and flywheel combo has a pretty aggressive chadder after a drive sitting in neutral. But that chadder has always been there even with the 7mgte, same clutch and pressure plate used in both engine. I had the car jacked up on all four wheels. The knocking is corresponding with engine speed.
 

A70nut

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No it doesn't make that sound in neutral with the clutch press in. This clutch and flywheel combo has a pretty aggressive chadder after a drive sitting in neutral. But that chadder has always been there even with the 7mgte, same clutch and pressure plate used in both engine. I had the car jacked up on all four wheels. The knocking is corresponding with engine speed.
Ok, so it doesnt make the sound in neutral with the clutch in or out. Does it make the sound in gear with the clutch in? Have you checked to make sure you dont have any metal on metal contact with the body anywhere that could lead to a loud contact point? What type of engine and trans mounts do you have?
 

mk3turbo

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Ok, so it doesnt make the sound in neutral with the clutch in or out. Does it make the sound in gear with the clutch in? Have you checked to make sure you dont have any metal on metal contact with the body anywhere that could lead to a loud contact point? What type of engine and trans mounts do you have?
With the clutch in while in gear idling no knocking. But as soon as u slip the clutch out and give some gas to go the knocking is present, then if i clutch in and rev it, the knocking is not there. I have the mk4 supra motor mounts and stock r154 trans mount that originally came with the 7mgte. Motor mounts and trans mount are the same ones i use on my first 2jzget swap with the stock pistons (before the 2jzge was tored apart for the rebuild.). Doesnt look like its got metal on metal contact with the body.
 

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driveshaft related maybe? can you get someone to stand beside the car when you slowly load the clutch, and see if they can tell where the sound is coming from? is it just a sound, or can you feel it?
 

mk3turbo

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driveshaft related maybe? can you get someone to stand beside the car when you slowly load the clutch, and see if they can tell where the sound is coming from? is it just a sound, or can you feel it?
Its just a sound, no vibration. We did tried that and it sounded it like its coming between the head and block area near the firewall. But not exactly sure. We have to drive the car back and forth with the hood open so it was hard to tell.
 

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Its just a sound, no vibration. We did tried that and it sounded it like its coming between the head and block area near the firewall. But not exactly sure. We have to drive the car back and forth with the hood open so it was hard to tell.
Sounds from what you're talking like the problem is clutch related. Can you hear it more with the inspection covers off?
 

mk3turbo

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Sounds from what you're talking like the problem is clutch related. Can you hear it more with the inspection covers off?
The thing is that i tried doing that on 4 jack stands and the sound doesnt come on. It only comes on with weight to the ground moving/rolling in gear. Say I would in like say 2nd gear rolling 5000rpm, the knock is there knocking then i would clutch in and rev it to 5000rpm and the same knocking is not there by doing that and then clutch out rolling in 5000rpm the knocking is present again.
 
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Have you checked the bearings on the clutch release / pilot bearing?
Or have you checked that all the clutch slave parts are not damaged/loose/something else?
 

mk3turbo

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Have you checked the bearings on the clutch release / pilot bearing?
Or have you checked that all the clutch slave parts are not damaged/loose/something else?
I reused the same flywheel, clutch, pressure plate, put a new pilot bearing and new slave cylinder in there. The throw out bearing looked to be good thats why i reused it. Ever sinced the rebuild i havnt looked into it yet, mybe in a week or two when i have the time, ill pull the trans off and inspect it.
 
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A70nut

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Following to see what it ends up being, sounds input shaft area related though as wheel speed doesnt affect it.
 

mk3turbo

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Alright i pulled the trans off today and everything looks normal. Flywheel is tight, no cracks. Clutch and pressure plate looked normal. There is some play between the pressure plate and the throw out bearing but i think thats normal. Other then that im leaning towards the bottom end now.
 
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suprahero

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How can it be the bottom end? If it was motor related, it would make the noise all the time, not just when it's in gear under a load. It's got to be in the drivetrain somewhere or I've misread your description.
 

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Have you drained gearbox oil? Problem from there maybe?
it doesnt sound like an engine problem. Or it would have failed with that time.
 

mk3turbo

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How can it be the bottom end? If it was motor related, it would make the noise all the time, not just when it's in gear under a load. It's got to be in the drivetrain somewhere or I've misread your description.
At this point ive already dig into almost everything except pulling the motor and have a look inside. Drive shaft, i would cruise at like 70mph with steady rpm, no knocking sound but once i give it some gas or wot the knocking sound is present. The transmission shifts smooth regular driving and even shifts great during wot. I use redline mt90 fluid.
 

mk3turbo

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Have you drained gearbox oil? Problem from there maybe?
it doesnt sound like an engine problem. Or it would have failed with that time.
I did drain the gearbox, looks a little flaky. Looks like i put a little too much mt90 fluid in there.
 

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If you are getting metal shavings out of the oil in the trans the issue is likely that.
Tear down the trans and find out what's grinding itself apart.

You say the sound isn't present unless the clutch is engaged and spinning the input shaft in the trans.
You are using an R154 right?
Even if the car isn't moving it's still spinning the input shaft.

My money is on: broken 1st gear thrust washer or something else broken on the input/ main shaft.

Have you rebuilt or upgraded any internals yet on the trans?

Not likely anything related to the engine.

Side note: When I upgraded everything in my trans there was some very visibly worn cast Al shift forks, one had a big chunk missing too.
It wasn't abused, just worn out with age.
The trans needs the upgrades and new parts all around especially behind engines with higher HP.
 
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mk3turbo

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If you are getting metal shavings out of the oil in the trans the issue is likely that.
Tear down the trans and find out what's grinding itself apart.

You say the sound isn't present unless the clutch is engaged and spinning the input shaft in the trans.
You are using an R154 right?
Even if the car isn't moving it's still spinning the input shaft.

My money is on: broken 1st gear thrust washer or something else broken on the input/ main shaft.

Have you rebuilt or upgraded any internals yet on the trans?

Not likely anything related to the engine.

Side note: When I upgraded everything in my trans there was some very visibly worn cast Al shift forks, one had a big chunk missing too.
It wasn't abused, just worn out with age.
The trans needs the upgrades and new parts all around especially behind engines with higher HP.
Using a r154 trans, its still stock trans. The trans was fine before the tear down of the motor. When i have everything put together, fired it up and i could already heard the knocking when i back out of my garage.
 

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The difference between this video and the other one is this one the car isn't under a load, I thought you said it made the noise when the car was under load. Or did I miss understood it?
 

mk3turbo

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Don't waste your time pulling the motor down, you wont find anything. Your second video proves that the motor is fine
I got ahold of a spare trans, stock clutch and pressure plate. Imma swap that trans and clutch with a different throw out bearing setup over to see if thats the problem. One issue i did see was the input shaft tip where its insert into the pilot bearing is burnt up on the shaft and also is the the pilot bearing on the inner opening of the pilot bearing. But the pilot bearing seem to still look ok, still spins freely. Not sure, that just might be my problem.
 

mk3turbo

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Update on this....

I slapped on a different transmission with a stock pressure plate and stock clutch, new throw out bearing and pilot bearing, same knocking still there.


I pulled the motor, checked all the rod bearings and main bearings. They are all clean, no scoring or anything bad. At this point I dont know what else to check that could make that knocking/tapping. Its been a nightmare trying to diagnosis this knocking noise.
 
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A70nut

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How was the flywheel? Flywheel bolts? What did the thrust washers look like? How does the crank pulley look? Clutch throwout bearing fork ok?
Update on this....

I slapped on a different transmission with a stock pressure plate and stock clutch, new throw out bear and pilot bearing, same knocking still there.


I pulled the motor, checked all the rod bearings and main bearings. They are all clean, no scoring or anything bad. At this point I dont know what else to check that could make that knocking/tapping. Its been a nightmare trying to diagnosis this knocking noise.
 

mk3turbo

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How was the flywheel? Flywheel bolts? What did the thrust washers look like? How does the crank pulley look? Clutch throwout bearing fork ok?
Flywheel looks fine, flywheel bolts wasnt loose or anything when i pulled the trans off. Crank pulley looks good, fork was good no damage. I forgot about the thrust washers, its got some scuff marks on it, ill take some pictures tomorrow when i have time.
 

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