Help...humming noise and slight shudder from the rear

[leon_s]

Hi guys, I'm a newbie here. I picked up my E46 about 3 months ago. It's a 2002 318i with M43 engine. Not powerful, but since I live in a country with extremely heavy traffic, I'm pretty happy with the engine performance. However, there are 2 major problem that are really bothering me..hope you guys can help my in finding the solution.

I've been having this problem since 2 months ago and still looking for answers. Here's the problem. When I drive at around 45-55 mph I can hear a faint humming noise (sounds like "woo woo") coming from the middle rear area. No vibration yet. Just the noise. It only appears at this range of speed. Any faster or slower, it's gone.

The second problem I've been having is a slight shudder at around 65 mph and above. Again, not really sure where it's originated, but if I have to guess it's coming from the middle rear again. I don't think it's the tyres, though. The shudder doesn't amplify as I drive faster. But if I slow the car down to somewhere below 65 mph, it's gone.

I though at first that wheel bearings were the culprit, so I changed them. It didn't solve the problem.

Can anyone here please shed some lights on this matter? I'd appreciate your help...

cheers

[gixerdave1983]

sounds like both the noise and the vibration is coming from your differential, sometimes changing the oil can make a difference but failing that it will need a new diff

[leon_s]

Originally Posted by gixerdave1983

sounds like both the noise and the vibration is coming from your differential, sometimes changing the oil can make a difference but failing that it will need a new diff

Thanks mate, I'll most probably start from here

[Manolito]

I presume that when you did the rear wheel bearings you carefully examined all the CV joints? I don't think that the joints are available as separate parts. I think you have to buy the whole axle. The worst part of that would be that you just had it apart doing the wheel bearings and you would have to tear it apart again to do an axle. A speed-related noise or vibration makes me think more of a joint than a differential.

Tires can be quirky as well, so jack it up and examine them carefully while spinning them. Check all sidewalls for cord separations.

The original Continentals on our '04 330 made a terrible rumble sound at highway speed once they got down to the treadwear indicators. With a new set of Michelins, it sounded and rode like a different car.

[leon_s]

Originally Posted by Manolito

I presume that when you did the rear wheel bearings you carefully examined all the CV joints? I don't think that the joints are available as separate parts. I think you have to buy the whole axle. The worst part of that would be that you just had it apart doing the wheel bearings and you would have to tear it apart again to do an axle. A speed-related noise or vibration makes me think more of a joint than a differential.

Tires can be quirky as well, so jack it up and examine them carefully while spinning them. Check all sidewalls for cord separations.

The original Continentals on our '04 330 made a terrible rumble sound at highway speed once they got down to the treadwear indicators. With a new set of Michelins, it sounded and rode like a different car.

The whole suspension system has been professionally checked but I didn't receive any reports about broken CV joints. Can anyone post a pic what a CV joint looks like and where it's located? Sorry for the stupid question..noobie

[Manolito]

Go to Bimmerparts.com and look up the rear axle for your car. You will see that it comes with two accordion-shaped rubber boots on it. The CV (constant velocity) joints are inside those boots. It is not easy to tell if a CV is noisy because a little bit of rotational "play" in the joint is normal. It is the amount and direction of the play that you have to watch for. It should not have any lateral play in it.

[gixerdave1983]

a CV joint wont wont generally make the whole car vibrate....a diff will.....nor will a CV joint hum...a diff will........CV joints click loudly like your running a stick down some metal railings

[Manolito]

The e36 has a hanger bearing in the driveshaft that can make noise and vibration when it fails. It is a bit of a pain to replace. If the e46 is the same design, that is another possiblity.

[RacerJames666]

Or guibo......
But your no vibration part.....stifling!
Maybe subframe bushings along with a failing support bearing?

[mpower318i]

it could also be a drive shaft that is out of balance due to improper instalation that would take care of you shuttering but the humming noise could be the differential bearings where the driveshaft enters at the front of the Diff. Now you said the it only shutters at about 65 right?...check the differential and make shure that it is not bent or has a dent in it. Also remove and spin the drive shaft in any direction re-install and then drive it to see of the problem still persists. I've come across the same problem on an 2005 f-150 there is a special TSB on it on the Ford dealer website let me see if I can find it to see if there is a better description on how to fix it. nope sorry the only whay I can do it is to get the Tsb from work I can't pull it up from home I don't have a vin number...but there was a special service bulletin on certain model F-150 trucks that had an in-balanced drive shaft and at about 45-55 the whole truck would shake really bad...(you could see the passenger seat move) but it only happens when you are going up-hill and accelarating it said to " raod force the tires and replace if needed" or if the problem still persists then check drive shaft for uncentered mounting or "improper blancing" maybee I can scan the TSB and post it somewhere where you can read it...It will be on monday though.

[mpower318i]

did you figure it out?