2005 CL-600 Whining Noise at low RPM
-LeoD
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-LeoD

Wow! Looks like I started something interesting! Sorry I haven't been around, but since fighting my whining noise, I've had to fight cancer as well. In any case, needless to say my CL still "Whines" and it is worse now that it is Winter although it quiets down when it warms up.
At least in my car, it is not a high-pitched screeching noise ans what I have been recommended to do, is run the car without the serpentine belt. I think that will be best as it not need run but a few seconds for me to tell if the noise is gone or not. Has anyone tried that?
I have discussed this with several people I know and trust as knowledgeable when it comes to high end cars but none are experts on this particular vehicle and if I tally the scorecard I come up with the automatic transmission. Possibly the planetary gears or the the front pump.
I still need to have the exhaust checked as there is an MB technical bulletin addressing that and at least from reading it, it sounds like the noise is similar. But, frankly,I doubt that or an engine mount(s) are the problem as I had the mounts checked at 50K miles when the noise was not there and the transmission mount was shot. Replacing it smoothed the car so much I had not realized how bad it actually was but it never caused any noises.
Thanks for everyone's input; as soon as I figure this out and it makes sense (Not sure about a damper...) I will post it.
I have the exact same low pitched whine under 2000rpm as you but mine is a only a V8 so I doubt it's the something the serpentine belt runs... I also have changed the belt and idler as these were worn but the noise is still there....
The pulsation damper is next on the list unless you have found the problem yet???
Cheers
Hey Pete demepnding on the VIN you have it most likely will be 220 320 43 72 this line is off the pump and it comes very close to the tranmission so in order to charge it the tranmission MUST be removed, The line acts as a high pressure fluid line that if clogged or leaking will cause the car to hum on start up or low RPM. The hose is about $500 at the Stealer
use a long screwdriver (or similar stiff object that will carry vibration) and place one end on your ear, the other end moving around different components in the engine bay (while someone is revving up the car) and with this technique it should be easy to find out where the noise is coming from
does the sound happen in both park and in drive?
you only have to remove the 1 bellhousing bolt holding the high pressure line onto the transmission with a bracket. disconnect it at the ABC pump side and also at the pulsation dampener side and the hose will slide out from either the engine bay or beneath the car. removal of belly plastic pan is obviously called for in this situation
edit: having the car's hood in it's true service position (instead of just being open) will help a lot with accessing the bellhousing bolt holding the line to the transmission. utmost cleanliness is supposed to be demonstrated when dealing with the hydraulic fluid lines
you only have to remove the 1 bellhousing bolt holding the high pressure line onto the transmission with a bracket. disconnect it at the ABC pump side and also at the pulsation dampener side and the hose will slide out from either the engine bay or beneath the car. removal of belly plastic pan is obviously called for in this situation
edit: having the car's hood in it's true service position (instead of just being open) will help a lot with accessing the bellhousing bolt holding the line to the transmission. utmost cleanliness is supposed to be demonstrated when dealing with the hydraulic fluid lines
Thanks for the replies guys... had heard it was the CL65 that needs the trans removing to get the pipe out....
Anyone know why this pipe makes a noise?? the only thing I can think is that it's dirty??? in which case could you not clean it out??
Cheers
you only have to remove the 1 bellhousing bolt holding the high pressure line onto the transmission with a bracket. disconnect it at the ABC pump side and also at the pulsation dampener side and the hose will slide out from either the engine bay or beneath the car. removal of belly plastic pan is obviously called for in this situation
edit: having the car's hood in it's true service position (instead of just being open) will help a lot with accessing the bellhousing bolt holding the line to the transmission. utmost cleanliness is supposed to be demonstrated when dealing with the hydraulic fluid lines
Thanks
The MB STAR SERVICE Manual Library DVD in the DTB section states....
The ABC Pulsation Damper/Accumulator can correct a 'hum' or 'drone' sound. If a 'hum' or 'drone' sound up to 2000 rpm is heard, but gets drowned out by the sound of the engine above 2000 rpm, it could be as simple as the hydraulic lines contacting the body of the car. Have the lines inspected and if they clear the body, then replace the Accumulator.
The manual also SPECIFICALLY states that replacing the ABC pump will NOT correct the 'drone' sound problem.









