rear noise, E30,

[mzbmw325i]

Hello everyone,

I have a 91 325i, automatic, it was passed on to me after my dad wrecked my vw as a temp car until i find something else, but i have learned to appreciate it, and it has served me well so far as a daily driver, it has 199,000 miles, unbelievable!!

in the past 2-3 weeks i noticed a noise coming from the rear when i drive the car, the noise increases as i speed up and it can be a earache if i dont blast my stereo just to avoid hearing the pain. as far as i know only the rear shocks have been replaced, with Bilstein's. i don't know what to look for, it sounds like rusty kind of metal rubbing on something, if u know what i mean, kind of hissing sound.

would it be the rear rotors, bearings, breaks.

any advise, input is greatly appreciated

[witeshark]

Does it get louder during tight turns in a parking lot? The rear differential may need a lube change.

[nick_318is]

Might be a wheel bearing, they tend to make some noise when old and worn.

[mzbmw325i]

i just changed the differential oil over the weekend, redline stuff as per forum searches, i wasnt sure how much to add, so i just added up until it started to drip from the fill hole.

the noise starts as soon as the wheels start moving, so i assume its not the differential, is it possibl either break pads are touching the disk/rotor or cv boot needs grease.

i read the rear wheel bearings for DIY are a pain to do. how much would a shop charge to do them, i am in aizona, any of you know shops here to recommend.

this car has been running ok for the most part, also i notice lately when i press the gas pedal power is not that strong, i did a basic tune up, changed air filter, distributor cap, only the spark plugs have not been changed (thinking of doing those this weekend, w NGK copper ones.) any input on this issue?

thank you guys!

[MrHennarot325]

i had my differential go in my '84 325e, it was a whine that started right when the wheels started turning, i found this out because i jacked the rear up had a friend press the gas. I couldnt figure out what it was for the longest time.

it could also be a wheel bearing.
goodluck

[Dr1ve4fun]

I am in AZ too.. what part are you in? I know we got my car in pheonix and the people we baught it from own a few bmws they took them to some place called bo's. In Tucson where I am I still need to make a choice between either stutgard autohouse they fo basically all imports but started with MB as fas as I know and Jon Pauls independent bmw. Any other city idk...

[nick_318is]

I have paid around $300 for a wheel bearing + labor at a BMW Dealer if i remember correctly.

[c1apton]

Why would you only do the cap and not the plugs? It's a simple procedure. As far as your noise goes - i'd bet on a parking or a brake issue - if noise starts as soon as you roll - bearing is also a consideration but you have to go through brakes to get to bearings anyway. Could also be u-joint(s) - you're just going to have to dig into it. As mention earlier does it get louder more pronounced when cornering? Or when accelerating?

[mzbmw325i]

the noise starts when the car getmoving, its on throughout when driving straight or making turns, like i said above i did change the differential fluid over the weekend. it is very annnoying especially driving at high speeds, like something is steering behind my back, very "dry" rubish metal like noise, rusty. i am just trying to describe what it feels like.

the spark plugs will be changed over the weekend, i did not do them when i was changing the rest of the stuff because the auto stores do not have the NGK plugs i want to use, and the only store, BAP in Phoenix, arizona charges too high in my opinion. i mean 8-9$ per plug.

i appreciate the inputs.

[mullethunter3]

This could be completely wrong, but the noise sounds like you're describing it as a upper shock mount. Were they replaced with the Bilsteins? Does this noise remain constant or is it over bumps or is it while braking?

[mzbmw325i]

i posted my issue when i was at work, after work i decided to drive the car with no stereo on, just trying to listen for the noise.when driving at lower speeds (10-15mph) the noise is not that recognizable, but once i accelerate, above 25mph and on the noise increases, like i said it's that sound like 2 metal parts are rubbing each other, hissing, rusty like metal sound coming from the back, i can almost be sure its coming from the rear wheels but not certain. i don't know if it helps but my break signal on the check menu by the sunroof lights on and off once in a while.

the rear breaks were replaced last spring. would it be possible that i need to add more fluid in the differential, what is the specification amount for the differential?

yes the rear and front shocks were replaced with bilsteins, 2-3 yrs ago.

what is the parking break to do w/ it and how do a person go about checking it?

i also read that the fuel pump starts to make noise indicating the end of its life. when i stat the car, and in park i hear a winding sound form the back, i mean what parts are moving i the rear when the car is is in park, the differential/ drive shaft?

once again the noise is constant when the car is moving, once i stop and the noise stops.

i apologies for my limited mechanical knowledge but i am trying to do my best.

thanks

[nick_318is]

You might want to look into getting an e30 bently. I think you defintly should check into the park brake, unfortunatly i don't know a lot about it. Too bad your in arizona and not michigan i would volunteer to drive it and let you know what I think, I am very familiar with the wheel bearing noise.

From your new stuff I would suggest looking into the Brakes a little further. Otherwise at the wheel bearings. Can you say if it makes more noise when taking a turn a certain direction? I know that when they go bad the wheel bearings are capable of being pretty loud.

As far as diff oil i thought you just fill it till it comes out and you should be okay, someone please correct me if I'm wrong.

[Dudesky]

Sometimes it could be so simple. Last month I had a ton of metallic scraping noises coming from the rear, thought it was the parking brake. Turned out to be just a pebble stuck between the rotor and the dust shield

[mzbmw325i]

the noise increases as i increase speed and sustains till i take my foot of the pedal or i am stopping, once i take off again and speed up the steering sound comes on again, is it possible that the break pads are touching or "rubbing" against the disk?

[mullethunter3]

If the brake pads were, in fact, rubbing against the disk, it should make the same sound as if you were braking normally.

So to hopefully make this clear... the noise only happens when you are pressing on the gas pedal?

[mzbmw325i]

like i said the noise starts when the car is in moving, when i am coming to a stop/slowing down the noise comes to a halt, once i get going again the noise appears in the rear, but to me it sounds like its coming from both sides so it's difficult to pin point exactly from where.

i will lift my rear this weekend and check on the rear breaks, rotor, etc.

is it possible the break shoes for the parking break are the culprit, can i spray them w/ wd40 if they r rusty or whatever?

what rear break pads do you guys recommend, i think the once i put on were from auto zone, but lately i have bee shopping from www.autohausaz.com a local online vendor, very competitive pricing. are PBR-Repco Deluxe rear pads a good brand, they carry 'em for 25$.

[Dudesky]

Could also be a seized caliper, or maybe worn pads if your sensor is malfunctioning. Just throwing some more possibilities out there for you to check.

[nick_318is]

Brake pads are a matter of what you want to do, if you want just normal stuff find some oem replacement pads or something along the lines of what your looking for.

Take a look at this page Pelican parts e30 pads section even the $33.25 pads should be fine since they are oem replacement, and I take it your not planing on doing any really agressive driving in the e30.

[mzbmw325i]

yes, break pads are no big deal i guess, i am not planning aggressive driving anyway.

thanx for the tips guys.

[mzbmw325i]

haven't had the chance to see the rear yet. weather has been bad, raining and cold as a mother

this weekend i will flush the break fluid, and will get a chance to check the rear and perhaps the culprite behind that noise.