I posted before about this but I will try to give more information this time, maybe someone has had this same problem and can share any ideas or how they were able to resolve it. I have a '99 FRC - the noise I am getting sounds like a dry bearing, not so bad you think something is going to come apart, but just dry. It was making this noice every once in a while, now it's almost all the time. The noise could almost be mistaken for a loud vacuum leak, almost a hiss type noise, not a rumble at all. If I am driving at 40mph in 3rd and let off the gas and coast it will make the sound for a second then not do it, but while I'm coasting in gear if I depress the clutch the sound comes back and stays there. While the clutch is pushed in if I take the trans out of gear the noise will go away(you can hear it slow to a stop, takes a second or two)but put the trans back in gear and the noise comes back. While coasting with the clutch pushed in the noise comes back in any gear I put the trans in, however, you can tell whatever is making the noise is in relation to the speed of whatever gear I put it in. Coasting at 40mph with clutch depressed & put it in 5th the noise is hardly noticible, put it in 3rd it's much louder, put it in 2nd and it's louder yet, you can hear it spinning faster in relation to the lower gear. Also, if I am coasting with the clutch pushed in and the trans in gear & it's making the noise, as soon as I let out the clutch to the point of it grabbing, the noise quits. Sitting at a stop in neutral with the clutch engaged I can get it to make the noise but it's not as easy. I have to rev the engine to 3-4 thousand to get the noise, and at that the noise comes and goes, I can't get the noise to stay constant just by revving or even by holding it at different rpms. Also, while I'm driving, if I play with the throttle and get it where it's just off idle, but not really much of a load I can almost get the noise to be constant. The noise sounds like it's coming from the clutch and or torque tube area, it sounds to far forward to be in the trans, but at the same time I've never heard a throwout bearing make noise in the same ways as what this noise is doing. I'm baffled - I'm hoping someone out there has had this same issue and has an answer or advice for me. Unfortunetaly no matter what it is in there the whole car has to be torn apart to replace it!

 

That sounds exactly like the pilot bearing in the end of the crankshaft. It's very rare for these to go bad but from your description I don't think there's anything else it could be. A $10 part and load of work to replace it.

 

I also have a 99 FRC M6 and 80K miles. I have what I believe is the exact same issue. Did you ever find out what the noise is or where exactly it is coming from. It's driving me crazy not knowing what is wrong. Any info good or bad is welcomed. thanks.

 

There are 3 areas that can cause a bearing sounds:
1) pilot bearing, has a tingy sound, should go away when clutch is pushed in
2) throw out bearing makes a roaring sound, most noticeable when easing the clutch out in 1st gear
3) bearings in the torque tube, should stop roaring when the clutch is in(ie shaft is not turning)

Unfortunately to reapair any of the 3 requires pulling the drivetrain from the car. Once you get it out you can easily tell for sure which one is bad. Personally I would replace #1 and #2 even if they are not bad. Too much labor involved not to replace them.