New Member with some questions about mystery noise.

[beemeup]

Gidday guys I've just joined, because ive just brought my first bmw and have some questions I would like to ask about it, Hope you dont mind.

First of all I'd like to say that before I actually bought this car, I thought it was sacrilege for me to buy anything less than a 6 cylinder beemer, but on finding out how much the insurance costs I decided to try the 4 cylinder ones.. I was suprised to find that the engines are not that bad it seems to me better than many more "modern" cars ive driven in terms of drivability and sweetness. I only have a 316i touring but I really like it. Ill upgrade to something a bit gruntier when Money allows but till then Im happy with what ive got, apart from a few questions over this particular car which you may be able to help me with.

My questions are about a slight noise that im not sure about (bought it from ebay with only a short test drive in the dark!)
The noise initially sounded like i had a massive blob of chewing gum stuck to the tyre, as it kind of seemed to be in time with the wheel revolutions, this made me think it might be a wheel bearing problem, but when i take the car out of gear and coast, the sound isnt there anymore so i suspected maybe gearbox, or cv joints on the drive shaft or something like that. Its a rather vocal noise with correlating kind of pulsing feel through the car as you move off from stationary. over about 20 mph the noise completely dissapears, and it sounds as sweet as a nut, with no vibes whatsoever.

The noise is more prominent when accelerating than decelerating, but it is still audible in both cases.

Im actually quite happy with the car in just about every respect. I only paid 450 for it and its got virtually no rust to speak of, just a rip in the seat base and this noise. Other than that I really can not fault it mechanically. I am very fussy by the way, so I do wonder if Im just being a automotive hypochondriac in relation to this noise. I can live with the noise, especially since it goes away at normal speeds, I just want to ask you opinion of it incase it sounds like a common problem that can suddenly escalate to a undrivable car situation because I dont want to have to leave it on the side of some road if it goes bang.

could anyone speculate as to what it might be? I know its a long shot and you cant tell me from my crappy description, but maybe you can give me a bit of an idea so i can isolate it. Also how much would it be to fix such a problem? how much is a new driveshaft bearing to buy and install if it was indeed this item making the noise..
Could it be the diff?

Oh, and another question. the brake warning light is on. It's supposedly had recent brake service, new pads etc. if this is true, what could be making the light stay on. I notice sometimes the brakes have a slight squeel when my foot is not on the brake pedal, only when the brakes are warm though.. ie driving through hills etc

I would appreciate any advice..

thanks

beemeup

[Nelly]

Hello mate, and welcome to the Zone.

Firstly check the center bearing on the prop shaft - you'll have to drop the exhaust slightly and remove part of the heat sheild to see it.
At a guess, i'd say your diff was ok, when mine was on it's way out it gave off a whinning sound which is constantly there and increases/decreases with speed.

Ref your breaks, get them wheels off and check them for your self - don't trust word of mouth from a seller! Not to sure on the 16i's but the 20i's tended to worp their standard front disc's due to bad cooling, this could be the prob with yours - if in any dout, change the disc's and pads (checking the callipers at the same time)

Hope this info is of some use to you mate?

Neil.

[BenE30]

Is there any vibration through the car when you drive?? I am thinking the same as above check the centre prop shaft mount mate!!

thats my guess any ways!!

Hope that helps!

[PeteE30Tourer]

Welcome to the zone. We do have a forum specifically for technical questions like this, so i'll move this post there for you in the hope that you'll get a better response there.

Good luck!

[beemeup]

Thanks for the info guys, its too wet to check underneath today, so Ill hopefully do it tomorrow. In respect of the brakes, It does have receipts from a garage specifiying work on them, and they seem to work fine, the light and the occassional sqeak is the only problem.

Bene30, There is what I very loosely call a vibration when i accelerate up to about 20 mph, but then it goes away completely. The vibration can be felt more than heard, and the best way of describing it is to imagine the sound if you had a blob of chewing gum about the size of a digestive biscuit (the milk chocolate ones, not dark chocolate) stuck to the tyre. It's a very distinct but muffled thud thud thud kind of sound that is most apparant when accelerating. Its almost too slow to be called a vibration as it probably pulses at a rate of about 2 times a second, increasing with speed untill about 20 mph where it dissappears altogether. Ill check the bearing hopefully later today or tomorrow. What should I look for? just a bit of play in the bearing or what? Is this a known e30 weakness? How much to fix ? is it an easy home fix? and finally is it likely to let me down suddenly or is it a fault that gets noisier but hangs in there untill its obvious it needs immediate attention?

Thanks for all your advice guys.

Sorry if i raised this question in the wrong forum section mod.

[Gwynleym10]

Wobble wobble! Check your wheel bolts are tight as well! Also one wheel may be out of anglement.

[Luke]

about the brakes - maybe they didn't put the sensor back when they changed the pads?