I'm very new to the subaru world. I have wanted to find an impreza for a while. Well now that I found one i have lots of questions and probably will for a while. I have a 1993 Impreza AWD. I bought it as a fixer. It has some high miles (210k) and a few quirks with it's age. I don't think previous owners did any preventitive maintenance. The first quirk I want to fix is a loud hum from the rear of the car. I changed the rear diff fluid (it was a dark and thick gray ). Going to be pulling the rear diff to see what's going on. I mainly want to see if this car is good enough shape to keep for a while. If it is sound mechanically I'll be looking for ways to improve the horsepower (a little sluggish for my taste).
Well, that's a little bit about my car. If anyone has anymore questions or suggestions for me that'd be great. I'll try to keep everyone posted with developments. Any help on the rear diff or other possibilities for the noise please help.

 

Welcome to the site.

Rear hum could be several things including an exhaust leak, bad wheel bearing(s), diff, driveshaft, etc.

 

welcome to the boards and congrats on the new purchase

 

welcome aboard


my guess is tires

check the pressure and how the tires are wearing

 

Thanks everyone for the welcome and responses.
The exhaust is fine. The tire wear and pressure is normal. The bearings appear to be fine. I had it up in the air and did the wheel wiggle. Seems tight. Not entirely ruled out yet. I haven't checked the driveshaft yet. I will be working on it tomorrow night taking a closer look at the diff.
If anyone has some info about these cars (my year) and my problem please post. I'm looking to learn all I can.
Thaks again.

 

Update for anyone who cares. It seems I have found the source of the noise in the rear of my car. I got under my car and pulled the back plate off the rear diff and found three bolts loose and free in the casing. I checked the rest of the spots where the bolts are supposed to go and was missing five out of eight. The plate was barely attached to the main gear with three loose bolts (not the ones in the bottom of the case). Needless to say I was surprised and a little worried. Upon further inspection I found all the teeth of my gears were fine. Still look to be in great repair. No damage to any of the teeth!

I've ordered a whole new set of bolts through my local dealer and can't wait to fix it and get on the road. I bought the car and haven't been able to drive it yet except for my two test drives. Since then I had it parked and been troubleshooting this problem.

Thanks again to everyone's advice and help.