So the other night I was going on the on-ramp and did a quick pull in third gear, took it out to 7500rpms then shifted into 4th, and ever since then their has been this loud rattling sound coming from the engine bay on what sounds like the driver side. The noise only starts when I'm about 20% into the throttle now, but its a loud constant noise and I have no idea what it is. I let off the gas and it goes away, but once I reapply the throttle it comes back.

Does anyone know what the noise might be?

 

Coincidentally, I'm taking my car to the dealer tomorrow fror the opposite problem. When I let of the throttle and anywhere between 40-60 MPH I get my rattle. Try as I may I can't find where it's coming from but it does appear to be drivetrain related.

 

I did a little bit of searching and I might have spun a rod bearing....

 

Sounds like some kind of harmonic vibration. I would bet something came loose on your exhaust.

 

You would hear that any time the engine was revving just not on acceleration but on decceleration also.

 

Yea true, whenever I'm not on the gas, like say I'm coasting downhill and just using compression, then I dont hear the noise. I havent really had time to totally check out everything, maybe a broken motor mount or something, or something simple came loose and is rattling around..............I hope

 

Well..........it appears that the noise is coming from my TC. It's definately not a whine but more of a rattle\chatter. I know the TC is servicable but it always seems to need to be replaced and at 2k+ for some it's no easy feat.

Anything new in this arena?