Got a strange raspy noise when i de-clerate! only started to notice it recently. Had a new clutch and lightened sti flywheel a few months back, so new spig bearing, release bearing fitted. Its defo drivetrain related, coz when you disengage the clutch you cant hear it! plus the engine braking is much more exaggerated! it does'nt seem a major problem just yet , it aint that loud, just a niggling noise! oil is fresh but its just comma semi syn. but i wouldnt think the oil could be causing this?? Any ideas would be much appreciated!!!!

 

The increased engine braking is due to the lightened flywheel, perfectly normal, can't help with the rasp - some clutches are noisy on overrun but its more of a jingle/rumble rather than a rasp.

 

wouldnt the lightend flywheel reduce engine braking?

 

Lightweight flywheels can induce gearbox gear rattle when decelerating, it is most noticeable in 3. gear from 3000-2000 rpm. I have the same problem. It shouldn't cause any increased wear, but it IS annoying.

 

As far as I see it there is less inertia in the flywheel, hence on a closed throttle the revs can drop down to idle quicker. I stand to be corrected if this doesn't happen when in gear but I can't see why it shouldn't?