Just recently I have experienced a very high pitched intermittent noise while driving my 1998 230 SLK. It comes about every 20 to 30 seconds and seems to be random in duration. It sounds like it is inside the car but unrelated to the radio. Does not seen to make the noise when stopped. Has anyone else experienced this type or have asolution to this problem?

 

Is it a constant high pitched note like "screeeeeeeee," or a warble like "chirpchirpchirpchirp"?

If it's constant, might be a brake pad sensor. The sound should stop when you step on the brakes and begin again at random. Get new brakes.

If it's a chirp, I have the same problem and I don't believe it's my brakes.

Second, not to be a dick, but I just posted a thread three subjects below this one that used both terms "high" and "intermittent" in the subject title. Use the search button.