I have a 2006 CLK 500 with about 38k miles on it. I just purchased it a couple months ago. It has a small whinining sound coming from under the hood. It sounds like this (https://mbworld.org/forums/clk-class...clk-500-a.html) but not as loud. It kinda sounds like its an electric car. I took it into the dealership and they have had it for 3 weeks now. They have replaced the oil pump twice, 3 oil pressure values, timing chain and the oil pan. (The last 3 because they messed some things up). They said that they were fairly confident that it was the oil pump. The Service Advisor even said that there was a Technical Service Bulletin for this car and the oil pump. After putting the new oil pumps in the sound was still present. Today they compared it to a couple other CLK 500 / CLK 550's that they had in and they all made the sound but even the Service Manager told me that mine was noticeably louder than the others. I guess they are waiting on MB Engineers to get back ahold of them and they are going to go from there.

Does anyone have any ideas? Is a slight humming sound normal from these cars? It seriously sounds kinda like an electric vehicle. It definately gets louder at higher RPM's.

Please let me know. I really want my car back. They have had it longer than I have since I bought it.

 

I have an '06 CLK500 and I don't have that noise. Did you buy from the dealer? If so maybe get it declared a lemon and have them buy it back. Was it a CPO? I bought mine as a CPO with just under 17000 miles. I hope they gave you a nice loaner nonetheless.

 

Ya I bought it from a dealership. It was an independent dealership though so I don't know if the lemon law applies. It is a CPO so it comes with the extra warranty which is nice. The dealership has been great to me so far. I am driving a brand new c300 that had 47 miles on it when they gave it to me. I know they are working hard on the issue and can only hope that they can figure something out. I just don't know what to do if they end up saying they can't figure it out or they come back and say MB told them the sound is normal.

 

pulley adjustment.

 

I will talk to the shop foreman to see if he has checked that because I can't remember. I know he has done tons of different things, like look at the engine mounts for vibration. Thanks for the reply.

 

i had mercedes change my pulleys once before for making a squeaking noise that did follow the rpms. i also brought it back for them to do an allignment on it, just so you know.

 

there has been a TSB on the crank shaft pulley/harmonic balancer. have them check that out as well. there is sometimes a whining noise at start because the car is circulating oil but it goes away fairly quickly. do a search in the AMG forum and you can find some greater detail.

 

I don't think it would be the crank shaft pulley / harmonic balancer. The sound doesn't go away. It is a persistant noise. I will mention it though.

I got an update this morning from the dealership, since they were going to try getting me my car today. They were going to have me put some miles on it so I could see if the noise was better, worse or gone with all the new parts. I guess they had a factory rep taking a look at it and they have decided they need to do more testing on the engine. The factory rep will be back next week and they might be pulling the engine and taking it apart to see if they see anything. (*fingers crossed) They are 98% sure that the noise is coming from the engine itself.

I also mentioned the pullies to the Service Advisor today and he thinks they actually replaced a couple already. He also said that he knows they removed the belt and turned the car on and the noise was still present. So I think they have ruled out a problem with the pullies.

I am disappointed that they have had my car for going on a month but I am impressed with the dedication to fixing the problem. I have talked to the Service Manager and the Shop Foreman (who is the one that is personally working on my car now) and they seem like they are genuinely working hard at trying to get the problem resolved. I am just glad that they haven't said "This is normal for your car". It would be kinda hard for them to say that at this point. I am also glad that its under warranty. I would hate to know how much this repair would've costed me.

Thanks again for the replies and ideas. I really appreciate it.

 

Well it's still at the dealership. I actually think the sound is normal. When I mentioned it to the shop foreman today, he said it is normal. The only reason that he has my car apart is because it was "slightly louder" than the 3 he compared it to and he wanted to make sure that there was nothing else wrong. If you listen to this youtube video, you can hear the whining noise I am talking about. http://www.youtube.com/watch?v=iPeBKnpAHaM It's the noise other than the exhaust. These cars look crazy when the engine, transmission, front steering and exhaust are removed.

I give him credit for being thorough. Also my brake pads were getting a little low. So when I mentioned it today, he said he would do it for the cost of the parts and not charge labor since he already has my car in pieces. So I am getting the brakes done for $120. That's nice of them

 

i smell Lemon Law buy back, lol

 

I just started to hear a loud whine from under the hood yesterday... today my transmission went out! All I have is 1st & Reverse (and park, of course). Shopping for a new transmission now.

Good luck bro!