99 Tahoe Tranny Knock

Hello everyone, I just replaced my 5.7L engine with a re-manufactured one because the plastic intake gaskets GM installed failed. Just before this failure I heard a knocking from the engine bay. Thought it was the engine since thats were the sound was coming from.

With this replaced engine I still have the knocking. More so when under power. Sounds like the fly wheel area id where its coming from.

I still need to have the engine scanned to have the cam retard set. I have an appointment Monday with my local GM dealership. But now after the same plastic gaskets were installed rather than the new ones that are metal . The trust is gone.

Has anyone here ever had a knock from the tranny? Not the normal start up knock. But a real knocking sounds like tapping with a ball peen hammer at different intervals.

Thanks in advance.
Jimmy

Hello everyone, I just replaced my 5.7L engine with a re-manufactured one because the plastic intake gaskets GM installed failed. Just before this failure I heard a knocking from the engine bay. Thought it was the engine since thats were the sound was coming from.

With this replaced engine I still have the knocking. More so when under power. Sounds like the fly wheel area id where its coming from.

I still need to have the engine scanned to have the cam retard set. I have an appointment Monday with my local GM dealership. But now after the same plastic gaskets were installed rather than the new ones that are metal . The trust is gone.

Has anyone here ever had a knock from the tranny? Not the normal start up knock. But a real knocking sounds like tapping with a ball peen hammer at different intervals.

Thanks in advance.
Jimmy


4X4 ??? could be the transfercase.

4X4 ??? could be the transfercase.

Maybe, i checked my timing and its at 21° advanced. Would this make it k knock.

Maybe, i checked my timing and its at 21° advanced. Would this make it k knock.


you think it sounds like a piston knock ? if so get a pro to listen to it and contact the rebuilder.

you think it sounds like a piston knock ? if so get a pro to listen to it and contact the rebuilder.

The knock isn't constant. Kind of speratic. I've heard Piston slap or knock. The Transfercase is quiet. The sound comes from either the transmission or the rear end of the engine.

I'm taking it to the dealer tomorrow. :crying:
Thanks for the responce j cAT.
jimmy

The knock isn't constant. Kind of speratic. I've heard Piston slap or knock. The Transfercase is quiet. The sound comes from either the transmission or the rear end of the engine.

I'm taking it to the dealer tomorrow. :crying:
Thanks for the responce j cAT.
jimmy


with this info you gave , check the flywheel / transmission fasteners. you can get a clunk noise if these are loose. these need locktight and use of proper torque. also replacing the bolts is a good idea if you now find loose. inspect for quality first .

I found the problem. Thanks to j cAT suggesting I check the flywheel /tranny bolts.

The problem was the spur gear in the starter. As soon as I dropped the starter I saw the gear fall foward. The gear was floating back and forth tapping into the flywheel. :rofl: The gear should not move freely. It should tuck back into or nearly into the staters bell housing.

Im still taking the truck to the dealer to have the timing/cam retard set.

Again thanks for this site and to j cAT for his help.

You all just cant imagine the relief I have. Ill sleep sound tonight.

I found the problem. Thanks to j cAT suggesting I check the flywheel /tranny bolts.

The problem was the spur gear in the starter. As soon as I dropped the starter I saw the gear fall foward. The gear was floating back and forth tapping into the flywheel. :rofl: The gear should not move freely. It should tuck back into or nearly into the staters bell housing.

Im still taking the truck to the dealer to have the timing/cam retard set.

Again thanks for this site and to j cAT for his help.

You all just cant imagine the relief I have. Ill sleep sound tonight.


it was your saying the noise was from the back of the engine that got me thinking of the flywheel hardware.

best have a shop set the timing with the correct tools.

good luck with the engine.