Weird "white noise"

[jon_harley]

For about a week, my CLK has been occasionally been emitting bursts of what I can only describe as "white noise" (static). The bursts of noise are high pitched and only last half a second or so. Sometimes I hear one when cornering at speed, but once or twice I have also heard the car make this noise when parked (for 10 minutes or more, with the ignition key out). As far as we can make out the noise is coming from somewhere at the front nearside but it last such a short time and is so intermittent that it's hard to pinpoint.

What could this noise be? It sounds electrical (like an untuned radio) yet can happen with the ignition off. Can anyone think of any other system that could make such a noise?

 

[BarryG]

I get the odd burst of white noise from a black box in the passenger side footwell. It is connected to the handsfree unit that was in the car when I bought it. From all accounts it took a Nokia 1
As my car had Methusala as a previous owner dont think your new one will have the same problem.
I'm not going to disconnect it though, as the car is sure to stop working too.

 

[jon_harley]

I do have a handsfree kit that I don't use, but I can't see a black box and the noise is much louder outside the car than in, so I don't think it can be anything like that. I can only imagine it must be to do with the car's alarm. Do these cars have the kind of alarm that can be set off by rocking the car from side to side? I've noticed the noise on cornering (but also when parked, which is not good).

 

[Dave's E55 AMG]

I get that white noise over my radio (CD, TV, phone and DVD are clear)it builds up to a level that I can't hear the music it then goes off for about 2 seconds then comes back on crystal clear. It does it about once a month. I think it's static related it's as if the car builds up the static then discharges it all in one go. That's my theory anyway, I've got used to it.

 

[jon_harley]

I get that white noise over my radio (CD, TV, phone and DVD are clear)it builds up to a level that I can't hear the music it then goes off for about 2 seconds then comes back on crystal clear. It does it about once a month. I think it's static related it's as if the car builds up the static then discharges it all in one go.

That does sound like a build-up of static. But isn't my problem as it can happen twice in 2 minutes, and does so even long after the ignition is off and the car locked up.

Yesterday I was driving along the A45 and the car alarm started going off. It went on and off intermittently for a couple of minutes before falling silent again. So I'm pretty sure the white noise is alarm-related and have an appointment to get it looked at.

 

[rajinder_1]

Jon as your in cov, take it to GM services on Lythalls lane they may be able to help you, ask for Craig..

Raj

 

[jon_harley]

I'd already booked it into M-B Cov but I will look up your recommendation when the warranty runs out!

It was indeed an intermittent alarm problem, traced back to the rear SAM unit, replaced under warranty.