Just Bought '87 325e - Two Q's - Exhaust ID, plus Mystery Noise in Rear End

[NJGreenBudd]

Got to drive it around for a while today, pretty cool car but it has one or two issues that need attention, Also moved it into the garage today:





Couple of questions though, there's a noise that develops around 30mph which seems to be coming from the rear of the car. It's pretty loud and seems independent of throttle position, rpm or gear. It's like a constant droning/rumbling noise that gets louder the faster you go. Doesn't sound like the trans or diff though, more like a tire rubbing on something. I can't see any rub marks and everything appears pretty much in good condition in the suspension. What should I be looking at here? Driveshaft? Wheel bearing?

Also is this the stock exhaust for a 325e:







Thanks for your help!
-NJGB

[Quadrajet]

The noise could be one or both axle bearings. Mine was both and my diff.

One way to check is to put car up on stands then run in gear, then it's a fairly easy matter of taking a stethoscope and pinpointing the source of the noise. If you remove the wheels you take them out of the noise making business, and get better access to items of interest. Watch out for all the stuff rotating though.

Or up on stands, not running, and grab the rear wheels and see if you can push/pull the wheels like you would bicycle handle bars to check the wheel bearings.

[reelizmpro]

No, it's not the stock exhaust.

[NJGreenBudd]

Yeah that noise is my biggest problem. I actually have new cat and muffler on the way but was curious if that was the stock exhaust. Thanks for your input. Any more suggestions.

[ethree]

Get a chip. And while replacing your dif get a limited slip unit with shorter gears.

Any more suggestions.

[87e30]

How does the e30 compare to FC, in your opinion of course.

I've been lusting over FCs lately.

[NJGreenBudd]

I will look into the chip, I heard they do good things for the eta.

I have only been driving the BMW for a few days but it is obviously a much more docile ride than my Turbo II. The RX7 has Rtek7 2.1 ECU, T04B V-trim @ 13psi, Stance GR+ coilovers, etc.... the 325 is stock so it's even more drastic of a difference. The 325 feels slow and soft, where as the Turbo II is nasty quick, loud and very rigid. I have completely different uses for each car, the TII is my fast car and the BMW is my cool old car. I like having a car that is stock again, get to enjoy it the way it came from the factory.

My RX7 Turbo II :

http://i23.photobucket.com/albums/b359/NJGreenBudd/100_2566.jpg

So does any body else have suggestions for diagnosing the noise I'm hearing?

[Red88]

Info on the rx-7?

[NJGreenBudd]

It's a 1987 Rx7 Turbo II with new 13BT block and FD manifolds, upgraded Rtek7 EMS and fuel system, BNR Hybrid turbo with full exhaust, GReddy Profec B Spec 2, custom VMIC, Stance GR+ coilovers, etc....

http://i23.photobucket.com/albums/b359/NJGreenBudd/100_2588.jpg

http://i23.photobucket.com/albums/b359/NJGreenBudd/100_2592.jpg

http://i23.photobucket.com/albums/b359/NJGreenBudd/100_2549.jpg

I also have this 2002 Volvo S60 2.4T AWD, it's my daily driver:

http://i23.photobucket.com/albums/b359/NJGreenBudd/0801090737a.jpg

[Red88]

It's a 1987 Rx7 Turbo II with new 13BT block and FD manifolds, upgraded Rtek7 EMS and fuel system, BNR Hybrid turbo with full exhaust, GReddy Profec B Spec 2, custom VMIC, Stance GR+ coilovers, etc....

http://i23.photobucket.com/albums/b359/NJGreenBudd/100_2588.jpg

http://i23.photobucket.com/albums/b359/NJGreenBudd/100_2592.jpg

http://i23.photobucket.com/albums/b359/NJGreenBudd/100_2549.jpg

Mmmmmmm.