View Full Version : Rear engine humming...

03-31-2008, 10:11 PM
Hey guys, i've got a weird noise coming from the rear of my engine. I almost wanna say that it could be clutch related but not sure... The engine runs too good and healthy for me to really think that it's the motor. Oil Pressure is good, temps are good... Yet when i'm sitting still at idle i can hear this humming noise. I pop the hood and it's much louder coming from the rear of the engine. I have an aluminum intake manifold so of course it's amplified through there... I wonder if a bad pilot bearing could be causing something like this? Like i said, the engine sounds and runs fine... but when i pop the hood and listen the humming is definately coming from the rear of it, maybe where the tranny mounts to it... any ideas?

99 LS1, 6spd stick

228 cam, AFR 205 heads

weiand aluminum intake manifold


DFX Centorforce clutch disk

04-01-2008, 11:26 AM

04-01-2008, 11:35 AM
wow.....mine did the same thing.....sounded like the pilot bearing or the throw out bearing.....NOPE
spun rod bearing.....shitty

04-01-2008, 12:34 PM
I hope that's not the case... :(

04-01-2008, 05:25 PM
any other theories?

02 ss convert
04-01-2008, 06:28 PM
If you have the engine running with shifter in neutral and the clutch is released,the tranny input shaft and crank are locked together,and the bearing is not turning.This should eliminate the pilot bearing.With engine idling try to pry back release bearing from clutch disc,this would eliminate the release bearing.Idling in gear with clutch depressed the input shaft to the trans will stop turning this would eliminate the support and input bearing in the trans.Inside the motor is alot harder.If you hooked up a quick,non buffered oil pressure gauge you could hold the rpm at 1500,and snap the throttle quickly,if it drops the main bearings are bad.Rod bearings are usally a search and destroy mission.Good luck:bang: