High-Pitched Noise from Engine when parked
 

Greetings,
OK - new 'odd' issue. My 2006 E350 has begun emitting a short 1 second long high pitched sound while engine off and parked. The sound repeats itself every 15 seconds or so. Openeing the hood you can trace sound to the front portion of the engine (not the SBC box - but another smaller silver 'box' attached to the upper front-right of the engine).
Talking it for a short drive will often 'cure' it. If you don't, the quite loud (clear from even 20 feet away) high-pitched noise will continue, every 15 seconds, all night...
Ideas?:eek:
Thanks.

RE: High-Pitched Noise from Engine when parked
 

what part exactly was it? got photo?

RE: High-Pitched Noise from Engine when parked
 

My 05 500 does the same thing.

RE: High-Pitched Noise from Engine when parked
 

Hi Sleepwalker - I can take a photo tomorrow, but in the meantime it is a silver-metal rectangular shaped thing about 6"x3"x2" (total guesstimate) and is mounted high on the upper front right (facing the engine) attched right underneath the big plastic cover piece.
Thanks!

RE: High-Pitched Noise from Engine when parked
 

MB, I betcha both engines have this same accessory-looking-piece mounted to them. Let's see what Sleepwalker can dig up...

Thanks!

RE: High-Pitched Noise from Engine when parked
 

Dealer says it's the a/c unit they are replacing mine.

RE: High-Pitched Noise from Engine when parked
 

MB,
Really? An A/C piece making noise with the engine off?
I appreciate the update, I'll check with my dealer, too.

RE: High-Pitched Noise from Engine when parked
 

Mine goes in tomorrow the dealer said it is a valve involved with the a/c unit and that Mercedes is aware of the problem but "has no fix" So I guess that means if you complain they replace it.

RE: High-Pitched Noise from Engine when parked
 

.
Ha! I have to say you're right on the money with thatLet me know if the 'fix' works!

Happy Holidays