improved1

Ive read alot of articles about the different engine noises associated with the ls1 bent rod engine knock, the diesel sound on startup. Mine is a bit different, i can only hear it inside the car at idle warmed up in Drive. if it put it in neutral or park it goes away. i also have fluctuating oil pressure, will drop to 20PSI at fully warm go upto 40 on half pedal and WOT around 60. the noise almost sound like a thumping coming from the right side of engine, recently switched from 5-30 royal purple to 10-30 royal purple and the sound got a bit louder. any ideas?

ShevrolayZ28

iTrader: (4)

It's a little unusual for the oil pressure to drop to 20. Does it have a lot of miles on it?

improved1

im at 58k, which i dont think is too high

ShevrolayZ28

iTrader: (4)

It's still just a baby at 56K, but anything is possible.

I guess by the sound, you think it's the motor. Sure it's not drive train related? Maybe check stuff like transmission mount, cross member, motor mounts and maybe take a look at the flex plate. Make sure the exhaust isn't hitting anywhere. IDK...

improved1

yeah my dad and i looked at it today for a while, it will not make the noise in N or P when the engine rps are around 800. In drive and 1-2-3 you can hear the noise, ive had a thumping noise coming from the front right side of the car, possibly a ball joint or something, you cant hear this noise at all once the motor is past idle RPM,600-700 RPM. this is making my head hurt