I attempted to find out the answer to this problem a while back on the forums but nobody responded. This is EXACTLY what I have been trying to describe for a long time. It's only when I come to a stop light or stop sign, and only when I have my foot on the brake. When in park, no symptoms. It's a very subtle grinding noise and the car does appear to want to go forward more. Symptoms last about 2 seconds and then stop until the next light. FYI, I have an SRT6.

jamesknox, Please PLEASE let me know if you end up resolving this issue and what the culprit was.

 

For sure!
I take it in on Monday to get the Idler pulley replaced. If that doesn't fix it, it's going to be the Water Pump. I am HOPING; it's only the idler pulley.

Nevertheless, I will certainly let you know.

 

Did you ever find out what the problem was? Did it fix the grinding while stopped?

 

I told myself I was going to get back with you today.
So this is my update.

Took my car to the mechanic. We took the belt off and spinned the idler pulley; and it was fairly noisy (to be a pulley at least) --- He said my water pump had a little give in it so be prepared to replace that in the future but the noise should be cleared up with them replacing the idler pulley.

So...a few days later, I went in...they replaced the idler pulley. I drove off the lot...NO NOISE....I pulled into my neighborhood....the noise was there! I called them, they told me to bring it back....another mechanic went for a drive with me and certainly heard the noise. We got back to the shop, he checked it out --- about an hour later he said, "You know..you do need an oil change because your oil smells like 100% gasoline and that is probably what is causing the grinding (implying there is no lubrication) My oil hasn't been changed for about 5k miles so I told them to go ahead and change it.

They did....got in the car....the noise is still there. He is saying that these engines (same as SLK) have a bit of engine noise. He believed that what I am hearing is simply engine noise and nothing really to worry about. He informed me that he had seen a few crossfires with this same noise and the reason that we hear the noise more in crossfires as opposed to owners of the SLK is because the SLK has more insulation to block engine noises....or something like that.

Nevertheless --- the noise is still there. It still annoys me but I have no clue what to do. I woke up that morning going to get rid of the noise...instead, I spent $250 on "extras" --- grant it...they had to be done anyway...it was just a bit disappointing.

 

Bump to wake up an old thread with what I believe might be a similar problem (idler pulley noise)? Driving around town at speeds low enough where the wind/ exhaust noise are not too loud, I hear a high-pitched whining/grinding noise coming from the engine compartment. It is not the SC whine. When I increase the engine speed, the noise is even more pronounced. The car is my daily driver, so my ear instantly picked up the funky noise about a week ago. Strangely enough, I first heard the noise after rumbling from 40 to 0 mph over a rocky, offroad parking lot in front of the entrance to my base, leading me to think that the harsh vibrations combined with low pull from the crank pulley (I was on the brake and slowing to a stop) somehow threw off the belts track over the pulley. I know it's a rough theory, but it's the only strange event I know of that occurred before the weird noise began.

I've included a low-quality iPhone video so you can hear the noise:
A video from my phone | United States | By TempUser38c22e93ded94a476401c81f3ad80d0

Any ideas as to the nature of the noise? You can better hear the high-pitched noise when I rev the engine. I've done some searching around the forum, and this thread has the most similar sounding problem..

 

So I got a second opinion from a mechanic, and he thinks it's the idler pulley just under the SC pulley that is making the whine/ wheezing noise. The bolt on that pulley was vibrating and heating up much more than any of the others. I'd like to release the tension on the belts and change the pulley myself. Anyone know of a good spot to buy one? Also how involved is releasing the belt tension and working on the pulley system...