Hello all


My CLK55 208 has a whining noise, at idle and underway (when going slowly anyway). It sounds like an intake noise, almost like the noise you get from a turbo.


I slipped my drive belt off and thought my tensioner was a little noisy so I figured that was it. Cue two weekends later and I've replaced my belt, tensioner, idler pulley and a bit of skin on one hand! Lo and behold the noise is unchanged.


Hot or cold makes no difference. I just checked again and it appears to be coming from the area where the secondary air pump is. I pulled the connector on this and started the car and it made no difference to the noise.


I've read the E63 guys talk about their PCV or intake manifold? Not sure if that's applicable to me. Car runs and idles nicely.


Any suggestions?


cheers

Can be water pump, Timing gears from a bad chain/guides, intake leak.

Remove the belt and start, Is the wine still there? If so it is internal or wife placed a remote control speaker.. har!!

Anyway try that first and report, it will not hurt to run a cold engine without the belt for a few seconds.

Cheers, Gator

I did a bit more listening today and the noise appears to be related to the unit I'm pointing to (a vacuum unit or a pcv? not sure exactly what).


When I tapped it a few times with my keys the whine suddenly stopped, faltered and re-appeared, I think the same but possibly a little different.


I could hear it quite well on the 10 minute drive back to work though.

I have the same whine, sometimes very loud on start up...i read through some old post here on the forum and others complain about the same thing and there has been various diagnosis, but all of which eventually say its nothing to be concerned about despite it being so annoying. here is an example

https://mbworld.org/forums/clk-class...nd-engine.html

thanks TMJ, I read through that link


What concerns me is that I didn't use to have the whine (at all) so I'm concerned as to what has changed.


Interestingly, it's quite pronounced when I idle along in first and then back off down a driveway, it appears slightly more pronounced under deceleration (at low speed), making me think it's air or vacuum related.

I thought it might be my smog pump but I disconnected that and it's still there. I sounds like whatever it is, it is belt driven. Perhaps a pump?

To test for a belt driven noise:

You can remove the belt while cold and rotate each component by hand, a grit/growl feel would indicate a bearing.

In post 3 Black opal is pointing at an air diverter or shut off valve. never heard of one going bad but i suppose it is possible a piece if debris is trapped in the valve/seat.

Same photo to the left of his hand is an electric motor that fires up when cold and under high heat. It whines, try disconnecting the cable and listen again.
If the engine idles higher than normal check the vacuum connection at the engine for the brake booster. Mine was shot and leaking good.

Gator

Thanks Gator, that sounds interesting. I'll try a few of those suggestions on the weekend as the noise bugs me. I'm still recovering from last weekend after changing control arms and ball joints on my wife's W220, groan...

Once again, Gator to the rescue! Many Thanks

I did the front suspension on my wifes t-bird last month.

It was a success but I still hear the whine. (Har)

Best Memorial day Folks, Gator

A T-Bird, neat! I would rather work on that I think..




I had another listen this morning, the noise appears fairly dominating. I pulled the two pin connection on the electric motor that Gator referred to but there was no difference (I assume this connector will stop it running?).


Using a piece of hose to my hear, the whine/whistle appears strongest underneath where that electric motor is. Perhaps the gasket at the centre intake piece? When I switch off at idle the whine is the last sound to be heard.


Still idles and drives nicely. Although I probably wouldn't notice a few less BHP to be honest..

Just further on this


Today I removed by belt and checked everything by hand. With the belt removed I started the car and lo and behold the whine is still there, same as always. So that rules out a few ancillaries at least.


I've stuck my ear as close as I can and it still sounds top and close to centre, maybe a little to the right (or drivers side for LHD folk).


I haven't tried Gators other idea of the air diverter valve, but I did remove the connections to the air pump and no change. It's got me beat.


Perhaps a chain rubbing on a bad guide? I hope not, I don't want to pull my motor apart....


thanks again

Perhaps a video with sound, I am stumped and many of these are hard to solve over the internet.

Cheers, Gator

Could probably be chain guides. You don't have to pull the motor apart to do it. Just have to remove the radiator perhaps and fan and cowling and whatever else is on the front cover mounted to the engine. Then you can get to the cover. If you watch the video of them assembling the M113 engine, you will see more or less how it looks and have an idea of how to go about doing it.
A family member of mine had a failure on her W204 C2000 compressor. Something chain related which she reported to the mech was a noise from the engine on start up and when the engine was cold. He never heard the noise and returned the car after a day only to find a few days later the chain and cam gears were shot or something. Shockingly the car had low mileage around 120 000km so what gives? Rather be safe than sorry but luckily she got away with new chain and cam gears and of course guides.