Hello everyone,

Recent buyer of W221 '13 S63. White - no performance package.

I don't drive it as much but I have owned it for about 5 months and the metal grinding type of noise has been annoying my ears and confused where it's coming from. It's while driving and when idle as well. It comes and goes. The noise is there for roughly 2-4 seconds-ish at a time. It happens on normal accelerating (whether C, S, or M), highway cruising speed, or idle. The noise gets a bit loud when making a turn, say the highway ramps.

Once I open the windows, there is no noise outside at all. My friend stood outside to check and no noise outside but once I have the windows up, the noise is there and it's amplified with closed windows.

I've read another thread of someone saying their drive shaft was unbalanced due to "debris." It did not state what gives and how he fixed it, such an old thread. My car does not shake or vibrate on idle/cruising. The alignment seems pretty much on spot. Tire wear is even.

I would be ruling out brakes and wheel bearings as the noise comes while on idle as well. I know these have hydraulic suspension, which is very new to me. Could anything be up with that? Drive shaft? Transmission? Engine? Mind you, there's no CEL on. I'm baffled and so is my friend who owns a shop. He suggested it could be the transmission and might need a service.

Any suggestions? Past experience? Anything? Thank you.

 

To you have any issues with your climate control? Could be the fan motor underneath the glove box.

 

OP the A/C compressor can make noises as described.
If the pulsation damper fails for ABC it will make an annoying racket.
221 cars use a ‘duo pump’ for power steering and ABC. Separate reservoirs for fluid. Check that fluid levels are as they should be. Change those fluids and the filter for ABC.

 

thank you both for the response.


As of yet, no issues with climate control. The noise doesn't increase/lessen with the use of the climate control. Is there a motor mounted near the cabin air filter under the glove box?

I am completely lost where the noise could be from. But the AC compressor might sound reasonable explanation. Because as I speed up, the noise does too. When I park after driving for a while, the noise stays continuous but mellow.

Do these cars have two reservoirs for the hydraulic fluid? My power steering hose was busted a few months ago and the shop topped off the ABC fluid - the reservoir that's on the driver side. Where would the second reservoir be located?

I'll be looking into changing the filter. I do need to flush the coolant as well. Might as well do both. thank you.

 

Power steering fluid is a separate reservoir from ABC oil. It is close to the ABC reservoir. They use the same fluid. ZHM is what I’ve always called it.

I had had a blower motor and resistor die in my 221 car. Pretty easy replacement.

 

OP did you ever diagnose this? I seem to be having same issue on my S65