humming/drowning noise on SL500

[daz10dazza]

Hi all, has anyone experienced a kind of humming/drowning noise on a 1999 SL500? It seems to do this everytime the car is driven. Sounds like its coming from the middle to back end of the car, could this be prop shaft bearing? some days its not so noticeable but other days it almost defends your left ear after a journey of around 40 minutes. It can increase in noise the faster you go (around 80-90mph). Any thoughts would be appreciated, thanks

 

[television]

Have a listen to see if its worse when pulling or on the over run, foot of the thottle

 

[daz10dazza]

Hi again television, it basically gets louder as you increase with speed and gets quieter when you decrease in speed. My mechanic friend thought it could be a transmission bearing? About a week agao I had all wheels balanced and the front wheel alignment checked - the guy who balanced the wheels did mention 'there not the roundest wheels hes ever seen' ! If a wheel isn't 100% circular could this have an effect on the bearings? Thanks

 

[television]

I think that this will be the prop shaft center bearing.

Diffs never get very loud, would you do it your self or have it done. We had a member a few weeks back who did his own, but not an easy job without a lift.

It would not be tyres,,where are you in the uk

 

[daz10dazza]

I probably wouldn't try this myself but I would ask my mechanic friend if hed be interested in having ago. I'm near Ashford in Kent (TN25). Is this a costly exercise or just a labour intensive job? Thanks

 

[television]

Any mechanic would know if this is a center bearing or diff fault by the sound

the exhaust has to come off, the link is for a 202
http://forums.mercedesclub.org.uk/showthread.php?t=46449


I have sent you the how to papers

 

[daz10dazza]

Thank you so much for your assistance again television, your service is unbeatable. I will print this of and see my mechanic guy to discuss further. I'll let you know the out come when complete. Thanks again

 

[daz10dazza]

Hi again Malcom, thanks very much for your email detailing the prop bearing removal & replacement. This is most handy. Thinking about this problem and with the ongoing grinding noise I have from the car this makes sense either the prop or diff need replacing. One thing which can be abit anoying is when you pull away reasonbly quickly the rear passenger wheel always struggles to grip (yellow warning light on the dash 9 times out of 10 flashes). Anyway enough woffling I'll look into this with my mechanic and see where we go from here. Thanks again

 

[BRABUS R230]

Hi all, has anyone experienced a kind of humming/drowning noise on a 1999 SL500? It seems to do this everytime the car is driven. Sounds like its coming from the middle to back end of the car, could this be prop shaft bearing? some days its not so noticeable but other days it almost defends your left ear after a journey of around 40 minutes. It can increase in noise the faster you go (around 80-90mph). Any thoughts would be appreciated, thanks

I had a problem like this on my 1991 R129 500SL, it turned out to be a rear wheel bearing but it was difficult to find out which side it was, I had one side changed but the sound was still there, it turned out to be the other side, what i had noticed is that when i went around a large roundabout the sound almost stopped but when the car straightened out it came back! hope this helps

BRABUS R230

 

[daz10dazza]

Your message does sound like my problem, it'll generally do it from a standing start and once up to speed sort of goes away until you come across a bend or when breaking (sounds more like metal on metal when breaking slowly). Thanks for your reply, I've got abit of sorting out to do !!

 

[television]

Yes a good point on the wheel bearing, this could allow the hub to move and make contact with the backing plate

 

[daz10dazza]

If I took my car to a Mercedes garage to have them replace a rear wheel bearing what sort of price would I be looking at and would you advise having both done? Thanks

 

[television]

You will only have one fault, and the wheel bearing could well be it, do you have a good indie near you

 

[daz10dazza]

I used to use Medway Mercedes for servicing and general parts but they have now closed. I've recently moved home to Ashford and will give them a go, spoke to my mechanic friend and he said your have to wait for the problem to get worse before actually knowing what the fault is, not sure I really want to wait for something to get worse and cause any further problems !!

 

[daz10dazza]

Hi all, sorry for not being in touch recently. Finally had my sl into mercedes Ashford today to be looked at to find out whats been causing this drowning noise. Merc say there is absolutly nothing wrong with the car, took of all wheels - no bearing problems. Checked prop & diff - no probs again. They can't see anything wrong and can only suggest its down to the size of my wheels fitted. They are a AMG style 18'' and the fronts are 245 with the backs being 265. Merc say due to the size of the wheels and the fact that the tyres arn't the best you can buy this may be the only thing causeing this noise. Thank you all again for any suggestions received, again your help is most appreciated. Thanks, Darran

 

[television]

Thanks for posting back,,I run on 19" now, and I was on 18" some tyres that have the V section tread can wear badly and become noisy, what tyres do you have on the car

 

[daz10dazza]

They are 'fullrun' which i know arn't great but that was all the alloy wheel supplier uses. When they need changing i'll put some better quality tyres on. Hopefully should make a difference. I'm impressed with Ashford Merc, had the car all day, collected & returned it washed and didn't charge me a penny.