My 2005 S600 has developed a transmission whine at low RPMs (1000-1200). Most audible when driving speeds of 25-30 MPH. It's only noticeable from inside the car and sounds like it is coming from the transmission under the gear shift console. It is consistent even after car is warm and goes away at speeds above 30 MPH. It can also be detected when revving the engine to 1000-1200 RPM's in park.

Just had a transmission service where filter, fluid, and seals were replaced. This did not solve the problem.

Any ideas on what may be causing this?

 

When was the last time you had your trans fluid changed prior to this recent time? It might be the torque convertor or the trans pump.

 

It may not be transmission. Put the car in neutral and rev. I bet it's your ABC pump.

 

The transmission fluid has only been changed once. I did put the car in neutral but to be honest couldn't tell if the whine was still there. Can the torque converter, transmission pump, and ABC pump be tested separately to see if they are bad?

 

I have a similar issue on my 2005 cl65 (low RPM whine). I can only hear mine with the windows up and it "sounds" like it's coming from the gear shift area. The whine on my car is coming from the Tandem (ABC/PS) pump though. At first I was pretty sure it was my transmission but after taking it in for service my mechanic verified that it was my Tandem pump. Mine appears to be coming from the PS side of the pump because when I turn the wheel from left to right it changes the pitch of the whining. When I raise and lower the car no whining.

Not sure if this helps but thought I would post my experience with a similar issue.

-LeoD

 

I did have my ABC/PS pump replaced in 2010. And thinking back, I did get a ABC pump warning light come on sometime before I started noticing the whine. I'll start with the shop looking at the ABC pump again and go from there. Then look at the torque converter.

Thanks for the input!

 

Kind of sounds like the pulsation damper in the ABC system in my opinion. My car had a whine in the interior of the car by the drivers feet I thought. The whine would go away if you increased the engine speed. It ended up being the pulsation damper that had gone bad.
Cheap fix really. I did it myself and it cost less than $200(part and fluid). Here is a link on it. Good luck and I hope you find the issue.
Johan

https://mbworld.org/forums/s-class-w...iy-repair.html

 

Just read this last post. It is the pulsation damper for sure now. My car started all the same issues and the ABC light came on briefly when my wife was driving the car. I had to add some Pentocin into the ABC system when this happened also. The bladder in the damper has lost its pressure and fiiled with fluid which helps the ABC system maintain a sold pressure under light and heavy demands. For instance when under slooooow driving conditions and at idle it has a low pressure situation. The damper helps build up the pressure when not needed with a nitrogen charged bladder to off set all this.
Johan

 

I'm wondering if there is a "test" for the pulsation damper? I'm thinking my issue may be the damper as well (instead of the ABC pump indicated by my mechanic). Any advice?

 

I'm wondering the same thing. Can they test the pulsation damper? The car still raises and lowers itself by pressing the ABC button and the pump is not leaking at all. Any guess on how much for a shop to replace the damper?

 

If the car makes a wining noise at low rpm's and low speeds driving it is the damper. As soon as you rev up the engine the noise should go away.

 

Have you checked your transmission mounts/engine mounts? My car was making a whining sound at low rpm. Had both the transmission mounts and engine mounts replaced as they were shot. Cured the noise (and very slight vibration)

 

If anyone need a s65 / s600 722.649 transmission I have one for sale 900 plus shipping.