Mike 944

OK..1988 325ix (AWD)....here's the prob.
When I drive in 1st gear at any speed...everything is ok
2nd gear...same thing
3rd gear...above 3500rpm car makes a bit of noise (the noise sounds like when you are in to high a gear for the speed you are driving at...engine struggling sound along with rumbling in car)
4th gear...noise becomes louder...especially over 3500rpm and over 80km/h...the car starts to rumble a lot!
5th gear...didn't get there yet!!

What can this be?
At first I though motor mounts...but that makes no sense...
Could this be signs of tranny problems? Please tell me no!!
Here's some other things... Oil still hasn't been changed and seems a bit thick, and gas is 87 octane (Which I believe should be 90)
Could this be causing this?
Any ideas/suggestions?
Thanks,
Mike

Perry 951

Driveshafts, transfer case, wheel bearings. All could be part of it.

If the motor seems fine under load in 1st and 2nd gear, then it is probably something in the driveline.

Oh.. an oil change would be a good idea, and some better gas.

Thaddeus

I agree with Perry. The rumble makes it sound like wheel bearings to me, but the fact it seems associated with RPMs makes it sound like tranny issues.

Take care of the simple stuff first (oil change, etc), then move into the spendier stuff...

good luck

Thaddeus