I have a little noise coming from under the hood. I believe it to either be a loose flywheel bolt or noise coming from the input shaft bearing. Here are some things I have noticed about it.
-It sounds like a tiny metal bell ringing
-It is audible when the car is first started, and for at least 5-10 minutes
-after driving a bit it seems go away, or at least I don't notice as much
-I can only hear it when idleing or going very slow (not that loud)
-It goes away when I put the clutch in (why I think it could be isb)
-however when I have heard isb's showing wear, it sounded more like a brushing noise than a bell ringing
-I recently swapped a replacement block in and didn't use any loctite on the flywheel bolts allthough they were torqued to spec.


The fact that it goes away when I put the clutch in makes me think it is the isb, but I figure that it is possible that it could be the flywheel bolt(s) and when the clutch releases it is no longer at a vibration that causes resonance.

Maybe something else in the tranny?

Any help would be appreciated.
thanks

 

Bad ISB is usually a brushing noise, but I have heard them sound like a helicopter and a few other things. You will most likely have to drop the trans to inspect everything, and at that point you can wiggle the mainshaft and see if it has play. You may also be forced to split the case in order to 100% find out, this of course assuming everything clutch, flywheel, and external bearings are in good shape.

I dont usually use locktite on the flywheel bolts. I torque them to spec and never had an issue. I have however seen someone use AT flywheel bolts on an MT flywheel which caused noises and problems from them backing out (AT bolts are too short).