very wierd noise?

dave blackburn · 07-18-2002, 03:04 PM

I hear a wierd sort of rubbing noise/vibration when i'm starting out in first gear. The noise comes at exactly 1200 rpm. It kinda sounds like the tires rubbing on something (there not). If I do a normal take off in 1st when I let the clutch out and the revs drop below 1200 rpm I hear it, and I hear it again as the revs climb past 1200 rpm as I accelerate. Could this be some kinda harmonic vibration from something? I'm sure its not the clutch or throw out bearing because if I let the car idle in 1st with the clutch out at 850 rpm going very slow and speed up, I hear the noise at 1200rpm. Any ideas??? Thanks for your help. Dave

philinjax · 07-18-2002, 04:06 PM

I don't know what the noise is but, I would check to insure that the four tranny to engine bolts are securely tighted. You may have done this but check the CV joints, it's not leaking tranny oil, is it? Also check to insure that the tranny mounts are tight and that the exchangers and muffler are secure. Good luck at it.
Phil

red-beard · red-beard's Garage

If it occurs, stopped on pavement, in first gear, clutch in, then it is not in the Tranny, since shafts would be still. Could be the throwout bearing, but that doesn't seem right. They usually make noise when the clutch is in.

I'd get a "helper" and a mechanic's stethoscope and isolate where it's coming from. Have the helper hold the clutch in, and set the idle speed to 1200, then listen around to find it.

James

dave blackburn · 07-18-2002, 10:02 PM

Hey guys, thanks for your replys. Um the noise only occurs when I am accelerating in 1st gear when the tach reaches 1200 rpm, not if its idling at 1200 rpm. All bolts are tight, and if I let the car idle in 1st while moving (clutch out, no foot on gas pedal, goin' 2mph) and then give it gas to accelerate it also makes the noise at 1200 rpm. Can't figure out what it is, kinda sounds like the tires scrubbing or a wierd vibration. Thanks, Dave

dman · dman's Garage

I have a similar noise only it happens in reverse. If I back up my 10-15 deg driveway in reverse as I apply the gas I get a strange growling sound from the rear of the car. This doesn’t happen in any forward gears.