Monkey177

When I turn off my car, there's a hissing noise that goes on for several minutes coming from the front bumper area....sounds like the IC. Is that normal? And if so, what is it?

And then in the interior there's a noise coming from behind...sounds like it's coming from behind the rear panel. It's not quite a rattle. Sounds like some electronics or something making an extremely rapid light ticking noise. It happens all the time....I'm not sure if I'm being clear enough on describing the noise....but this one definitely doesn't sound like it's supposed to be there.

BrabusCLS

If its kind of quick, electric type noise i would say it is normal.
I was curious too when i heard this for the first time.
It sounded like some kind of failure of electronic or electric parts.

Monkey177

It's a rapid ticking noise but it doesn't go away. It's all the time while I'm driving...

byteman007

i also have this problem on my sl-55 2004 model. It started after 16K miles. I took it in for the B service and they replaced some parts for a recall. One of the parts they replaced was a voltage regulator. After that i keep hearing this clicking noise behind my seat and then my parktronic sensor goes off in the front at Full for a few seconds.

Another anamoly with this noise is the inside instrument cluster lights are not steady... they seem to radiate hi-lo

This problem only occurs when you go higher than 75 miles an hr and the kompressor kicks in.

I also get the Batter INdicator on the instrument cluster in Red and a message that says visit workshop

I think its the voltage regulator.

240Volts

the hissing noise sounds the same as the problem I had - I forget what it was exactly, but I think it's a small mal-functioning compressor or air pump of some type. Mine used to hiss for 5-10 minutes... when I told MB they called it in immediatly and replaced the part under warranty...

byteman007

Took it in to the dealer. They replced the Voltage Regulator. Seems to work better now...although the cabin lights are still not steady. They still radiate hi-lo

elbowyeish

My 2004 SL55 makes the same hissing sound. Sounds like it's coming from behind the driver's seat. I'm taking my car in tomorrow to the dealer so will update as soon as I find out what it is.

Do you guys know how to turn off the annoying beeping sound when you open the door? It only stops when I put my key into the ignition but I like using the keyless go. I can't find that function in the manual.

bltserv

I think I read in a thread here somewhere. Yes the dealer can turn off the "chime". I love how it says "Dont forget key". Even though I am using the
keyless go and the key is in my pocket. So next time I see my SA.
In about 2 months. Going to beg him to turn that daffy thing off.