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Cory
Cory, Mercedes Technician
Category: Mercedes
Satisfied Customers: 350
Experience:  Mercedes Tech since 1982
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I HAVE A 2001 S600 WITH A V12 ENGINE. THERE WAS A LOUD WHINING

Resolved Question:

I HAVE A 2001 S600 WITH A V12 ENGINE. THERE WAS A LOUD WHINING OR GRINDING NOISE. I HAD THE POWER STEERING PUMP/ABC PUMP REPLACED. NOISE CONTINUED. THEY SAID SYSTEM NEEDED TO BE BLED AGAIN. NOISE STILL PERSISTED. THEY CHANGED BELTS, AND FINALLY CHANGED THE PUMP AGAIN. THE NOISE APPEARS TO BE BETTER AT IDLE BUT IS VERY NOTICEABLE UPON ACCELLERATION. CAN YOU HELP?
Submitted: 6 years ago.
Category: Mercedes
Expert:  Cory replied 6 years ago.
Chat Conversation Started
Cory :

The belt needs to be removed completely, then started momentarily, to eliminate any internal engine problem. Then, if no noise, reinstalled and each accessory checked with a stethoscope.

Cory :

Thanks, Cory

JACUSTOMER-nyde26fn- : Cory,
JACUSTOMER-nyde26fn- : I'm sorry I had an internet problem and could not get to the answer. Are you talking about the belt to the abc pump? Which accessories would need to be checked ?
JACUSTOMER-nyde26fn- : Please respond when you come online again.
Cory :

No problem, Take the primary belt off first, then the secondary, or you can listen to all accesories with a stethoscope or long screwdriver, be careful not to interfere with moving parts!

JACUSTOMER-nyde26fn- :

Cory,

JACUSTOMER-nyde26fn- :

Please forgive me. I have been out of town for several weeks and unable to correspond by email. I still don't understand what you mean by accessories. Please give an example.

JACUSTOMER-nyde26fn- :

The technician did remove the primary belt from the powere steering pump and there was no noise. they said that meant that there was no internal engine problem. the powere steering pump was replaced. The noise persisted. The belt was changed and the system was bled numerous times. Finally, the pump was replaced for a second time.

JACUSTOMER-nyde26fn- :

I spoke with the tech who told me there was still a little noise, but basically, he was giving up at this point. He said they had seen several others with this problem.

JACUSTOMER-nyde26fn- :

My car still has the same noise and it actually seems worse. My husband drove the other day and we both listened. There is some noise at idle, and when you accellerate it becomes much louder and is almost like the noise you would hear from a stick shift car as the car goes into different gears. When you reach a cruising speed it is less audible, but you can still hear a little. When you put on the brake and the car begins to down shift it becomes very loud again.

JACUSTOMER-nyde26fn- :

We want to sell this car, and this noise makes it impossible.

JACUSTOMER-nyde26fn- :

I had another V12 engine before and it was difficult to find a technican qualified even at the dealership. Do you think this is a problem?

JACUSTOMER-nyde26fn- :

My husband wonders if it has anything to do with any of the components that make the engine so quiet normally.

JACUSTOMER-nyde26fn- :

We have absolutely no confidence in the dealership in Okla City. They turned an A+ Mercedes service dept into an F- Chevy service dept.

JACUSTOMER-nyde26fn- :

I do accept your answer, but I would like to keep corresponding with you to try to resolve this problem.

JACUSTOMER-nyde26fn- :

Judy Stidham

Expert:  Cory replied 6 years ago.

Unfortunately, I cannot listen to it. Does it sound like a power steering pump whine? A grinding sound could be water pump. Accessories are belt driven components. Air pump, water pump, alternator, air compressor, and idler pulleys. You can use a stethoscope or a long thin screwdriver to listen to each accessory. Carefully put the screwdriver end up against an accessory and put your ear to the handle, compare each accessory for the noise you hear the loudest. DO NOT LET PROBE INTERFERE WITH MOVING PULLEYS AND BELTS!

Customer: replied 6 years ago.

Cory,

It is definitely a loud whining noise. It is the same noise it had before they changed the power steering pump twice. It appears to be RPM related. It definitely is NOT a grinding noise.

There are no messages from the computer so I don't think it could be a water pump or an alternator because it has been going on for so long.

One problem is that we have lost all confidence in the dealership and the other repair shop.

Any more suggestions?

Expert:  Cory replied 6 years ago.
There won't be any computer messages if it is a mechanical failure(non electrical).Does it disappear without the belt?
Customer: replied 6 years ago.
The dealership said that it did and that is when they said we need to replace the pump
Expert:  Cory replied 6 years ago.
Well we are back to my original answer then,
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