1-pippin

hey this isnt about my s4, but my e30 325 ix, ive been hearing this wierd knocking/ratteling sound for like 2 weeks in the rear left wheel area. and just recently it began to get very loud and happen alot, and there is also a wierd smell thats very strong, it doesnt smell like brakes at all, it doesnt even smell car related, and the temperature around the wheel well is alot hotter than normal.
anyway the sound happens when cornering pretty hard or switching directions quickly, or going over small bumps that rattle the car is when i notice it the most. its a loud deep knocking/ratteling sound, like something is loose or something.

i just got new tires put on today and they did a visual inspection of the brakes for me and they said nothing was wrong, so im guessing its maybe suspension related.

im going on a 3 hour trip soon today so i need to know quick, i dont wanna be driving on the highway with a dangerous car.

Frank@AutoSpeed

the last thing i would do is drive it on a 3hr trip.

Sorry im no help just giving my 2cents

AvantS4me

Have you checked the wheel bearing?

1-pippin

would a wheel bearing be making a loud knocking sound? id think it would just be a constant buzz

1-pippin

and would it have such a stong smell??

S4lorn

diff? Check the rear diff fluid? Drive shaft?

I don't know know much about that car but that's where I would start.

jtamkin

I cannot explain the smell, but it's probably the rear suspension top-mount. Particularly if you've got aftermarket shocks/springs, those things fail and the rear shock bangs against the inside of the fender. I tore through three of them in 2 years. Does your car ride a little funny too?

It's been a while since I had my E30, but a standard (cheap!) upgrade was to get the top mounts from a convertible. There are M and aftermarket mounts out there as well.

just one example:<ul><li><a href="http://www.turnermotorsport.com/html/detail.asp?PRODUCT_ID=33521132104">Top Mount</a></li></ul>

MisterN

I had that problem on a e30 325is. Not only was the suspension top-mount toast, but the sheet metal that the suspension top-mount bolts into had cracked and torn. It was easier to see from the inside of the trunk, with the side carpet pulled out.

Had a rear half-shaft/joint go out on it too. That sounded more like a front CV joint clicking on a FWD car.

I don't remember any funny smells or heat with either of those problems.