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Mk3 supra 2jzget knocking after rebuild

6K views 68 replies 13 participants last post by  dsmturbo 
#1 · (Edited)
Ok guys 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. Any ideas what this could be.
 
#2 ·
Couple of things, use a screw driver on and press it against your ear and place it around different parts of the engine and list.

There is a few things to look for here, for example:

Did you install ARP rod bolts? If you did, did you get them checked / align honed to make sure they didn't go out of round?

Do you have the OEM dampener on? If not is it rubbing against some bolts (This does happen)

Do you have OEM cam gears or did you use the correct bolts on the cam plate? Inspect it to make sure it isn't hitting the bolts.

Hope this helps.
 
#3 ·
Ok guys 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 on. 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 drove the car about 2,000 miles now, the knocking, tapping noise stayed the same, hasnt got any louder, no hesitations. Compression is 200-210psi across the board. Its got the older style driftmotion flywheel, old school rps 6 puck clutch kit. Any ideas what this could be.
Ok guys 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 on. 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 drove the car about 2,000 miles now, the knocking, tapping noise stayed the same, hasnt got any louder, no hesitations. Compression is 200-210psi across the board. Its got the older style driftmotion flywheel, old school rps 6 puck clutch kit. Any ideas what this could be.
Ok guys 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 on. 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 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. Any ideas what this could be.
Couple of things, use a screw driver on and press it against your ear and place it around different parts of the engine and list.

There is a few things to look for here, for example:

Did you install ARP rod bolts? If you did, did you get them checked / align honed to make sure they didn't go out of round?

Do you have the OEM dampener on? If not is it rubbing against some bolts (This does happen)

Do you have OEM cam gears or did you use the correct bolts on the cam plate? Inspect it to make sure it isn't hitting the bolts.

Hope this helps.
It doesnt tap or knock upon revving it or idle, you have to drive to hear it. Its got stock rod bolts. Its got a oem dampener on there, oem cam gears. Cam plate bolt is not hitting anything. But one thing i failed to do, i know the crank pulley bolt is not torque to 239ft tq. I just tighten it with a power impact. Mybe that might be my problem.
 
#8 ·
But one thing i failed to do, i know the crank pulley bolt is not torque to 239ft tq. I just tighten it with a power impact. Mybe that might be my problem.
Pull the crank damper off and check it. If it came loose the damper may essentially be "bouncing" on the crank key. Left like this the damper will eventually destroy the crankshaft and/or itself.
 
#5 ·
Not recently but about 3 months ago. After the motor broked in i beat on it pretty good to see if it will get worst but it didnt. Could it be piston slap? Usually piston slap goes away after motor warms up, but that doesnt seem like its my problem.
 
#6 ·
It sounds like the early signs of knock, hard to tell over the internet. My buddies did the same thing after a rebuild... We pulled his motor in 1.5 hours and had the oil pan, it took me about 15 seconds to figure it out.... One of the rod ends never got fully locked in when he tightened it.

he inspected it and torqued it down and decided to roll the dice. At first everything seemed great, but he could hear a slight knock that eventually came back stronger and stronger over a short period of time.
 
#7 · (Edited)
I have my buddy drive it slowly up and down the driveway with the hood open and it looks like its coming from between the block and head. I ran regular oil 10w 30 to break in motor and switch to mobile 15w50 synthetic. The first oil
change i didnt see any shaving metal in the oil.
 
#10 ·
With that verified I'd lean towards early stages of rod knock. It's possible to that the bearing has worn enough for the clearance to be too large to maintain an oil film barrier between bearing and crank and with out an oil analysis you won't likely see bearing material in the oil at this stage.

Sounds like it's time to pull the motor again.
 
#11 ·
With that verified I'd lean towards early stages of rod knock. It's possible to that the bearing has worn enough for the clearance to be too large to maintain an oil film barrier between bearing and crank and with out an oil analysis you won't likely see bearing material in the oil at this stage.

Sounds like it's time to pull the motor again.
thats the last thing i want to do
 
#12 ·
I'd start with an oil analysis. Caterpillar dealerships should offer it, depending on where you are. They sell a pump and tube that you stick down the dip stick to retrieve a sample from, so you're not pulling a sample from an engine draining out the pan... little bit more accurate that way. Part number for that pump is 1U-5718, and if you ask nicely they might give ya a few feet of the plastic tube that is used with it. If not they sell that by the roll, but you won't likely need a whole roll...

Blackstone is also an oil sampling service that is well regarded. Either way, they'll be able to tell you what sort of ppm you're looking at with wear metals, dirt, water, antifreeze, all sorts of good info.

Best of luck to ya, sucks to find yourself in such a situation, but these things don't tend to get better by themselves, so hang in there and do the smart thing.
 
#14 ·
from your description i doubt it's rod knock. i've blown up a lot of motors and early rod knock is most audible with no load. like at idle when you snap the throttle to about 4k ish as you let off you'll hear it "knock knock". it can also be heard on cold startup especially if your car doesn't need to crank long before it fires up. at that point there is very little oil pressure you hear it for a split second then it'll go away as oil pressure builds. so if you can rev the motor at idle snapping the throttle making the rods "float" with no load i would not just start tearing the motor apart. oil analysis would be good for peace of mind but id look else where.

if it only makes the noise with the car is in gear with a load since it doesn't make the noise on jack stands i'd look into the clutch/flywheel. my buddy recently put a built motor in his g8 and had a knocking noise. couldn't figure it out then finally did and it was the torque converter bolts weren't seated completely. there was built up lock tite stopping them so he ran a tap on the threads retorqued boom problem solved.

imo you don't have enough evidence to determine if its engine internals. also a much more easy way to check the condition of the bearings is to simply pull the cam covers and removed a cam cap. if you cams/journals were in good shape before the build if you have a rod bearing letting go it most definitely score you cams and caps. i know this from experience it's part of the reason its SO hard to find a 7m head that isn't scored cause almost all them have had bearing damage at some point. every 2jz i've ran the cam/caps look immaculate. this is a simple test that's good to do on any new or used motor you plan to buy....
 
#17 ·
"it can also be heard on cold startup especially if your car doesn't need to crank long before it fires up. "

Piston slap too could be this sound. I have piston slap on cold start ups that sounds very similar to rod knock, but goes away as expansion sets in.
 
#18 ·
if that noise is piston slap, the clearances are off the charts wrong

my last truck had the 5.3....I am very familiar with that sound of piston slap until warmup

from your video it sounds way to loud for piston slap imho, and im with you on your previous posts to pull the motor and figure it out.
 
#19 ·
Not too sure on the piston slap cause that sound does not go away when warm up. On that video, supra was warm up about 30 minutes. That knocking sound comes on every gear with load. I would drive it for an hour and the sound is still there. On cold start, ill hear the knock/slap for one second and it goes away. Doesn't knock/slap on warm start though. Free
Revving in neutral, that sound knocking/slapping doesn't come on. Before i post this thread i put a different head on and the knocking is still there. So its not the head. I took off the serpentine belt and drove it, knocking is still present. Torque the crank pulley bolt to 239ft tq, knocking still there. 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.
 
#26 · (Edited)
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.
 
#27 ·
Alright i pulled the trans off today and everything looks normal. Flywheel is tight, no cracks. Clutch and pressure 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.
Yeah. Will be interesting to see the mains and rod bearings.
 
#29 ·
You didn't have a rod cap torqued properly.....forget about it pull the motor and get the crank properly done. That rod needs to be cut and resized. If those are rods that never been replaced or resized do all of them. Cheap build, poor assembly, and piss poor tuning will cause rod knock from the word go. Since your friend had the same problem I'd say you both need a lesson in proper engine assembly.....no disrespect intended.

I've made a bazillion post about this with the 7mgte, and the 2jzgte is no different when assembled improperly.

Hey Brent.....and everyone else
 
#30 ·
I've made a bazillion post about this with the 7mgte, and the 2jzgte is no different when assembled improperly
Kinda goes for all motors to some extent. Always entertaining to see people bag on the 7M, then turn around and have the same issue on the 2J.

Hey Brent.....and everyone else
 
#32 · (Edited)
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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