A question i'm afraid to post.. Whining noise SL500 R230 MY09

[Zac Smithers]

Recently bought an SL500 MY09 7 speed and have an occasional whine from the rear end (very noticeable when it does it) but have discounted diff whine because it raises and lowers with engine speed but definitely is coming from rear end, otherwise i would have suspected belt tensioner bearing - it's that kind of whine. Most noticeable when in manual giving her some stick but seems to go away in comfort. Probably due to lower revs.

Cars done 33k and has a spotty service record but is in mint condition and has been looked after, and until I bought it I don't think it has ever been gotten wet!

I hate to ask but any ideas? After being a car guy my whole life it's one of those hmmm.. that has an expensive sound to it!

 

[LostKiwi]

What tyres do you have fitted. V pattern tyres will often whine when they're half worn. Mine sounded like the wheel bearings were shot.

 

[Zac Smithers]

Thx I had already discounted drive train as whine raises and lowers with engine speed.

 

[oigle]

Engine speed or car speed?

 

[LostKiwi]

If its engine speed related it cannot be from the rear of the car.

 

[Craiglxviii]

It's surprising how sound travels. get someone to stick their head down into the front passenger footwell while driving along and varying speed.

 

[alexanderfoti]

It's surprising how sound travels. get someone to stick their head down into the front passenger footwell while driving along and varying speed.

I agree, best thing to do, get it on a ramp and drive it in gear. You can prod around with a stethoscope to identify the source.

 

[Wighty]

It's surprising how sound travels. get someone to stick their head down into the front passenger footwell while driving along and varying speed.

Make sure they have their seat belt correctly fitted during this process

 

[Zac Smithers]

Thx for the Ideas! I'll see if I can convince one of my mates to go for a drive in the boot and see if he can still hear it

 

[John Laidlaw]

Velcro your phone in the boot and record....

 

[Zac Smithers]

After some investigation the noise does indeed seem to be coming from the engine. Have to get the stethoscope out and see if I can pin it down. Hoping it's something simple like and alternator bearing...

 

[LostKiwi]

To check for belt related noises remove the belt and try it. It'll be fine for a short period.