Moedy

The first video posted is Hami's car. If its coming from the fuel pump then you can hear it come on before ignition. Try turning the key two clicks. Leave it there and dont start. If this is the noise you hear from the back then its the fuel pump

2ng

It is supposed to be the number 110 here. Tomorrow I'll try to find it and check if it makes noise.

Glyn M Ruck

There is nothing wrong with your English. I did not read your first post properly.

Yes, it's no 110 in the diagram. That is the petrol diagram but the pump is in the same place on a diesel.

The sequence of pumps on the diesel is:

Rear LP pump, Front HP engine driven pump, amplifier injectors - injection into cylinders.

Take out the lower rear seat & lift the RHS round inspection cover to expose the pump.

As said above. When you first turn on the ignition (AFTER STANDING FOR A LONG TIME) you should hear the pump start & then stop when the rail is up to pressure & ready for cranking.

Rudeney

My CLK550 makes the exact same noise, but mostly only when its cold. It seems to me to be coming from the top rear of the engine. I have yet to locate the exact source, but it's done it for over a year now, so I'm not too worried. Engines make noises.

Glyn M Ruck

These engines do make noises. The Poly V belt system makes a noise especially idlers & tensioners. While cold on a gasoline engine we have the added complication of the excess air fan blowing it's lungs out to reduce emissions during high idle & Cat warming.

Rudeney

Thank goodness for the Harmon-Kardon sound system. :-)

Glyn M Ruck

Indeed! - I'm actually surprised at how good the HK Logic 7 system is.

Rudeney

Not to get too far off subject, but I do like the HK. My favorite system was the Bose in my W163. My only complaint about the HK is that the Logic 7 "simulated surround" sometimes does some odd things and makes it sound like its switching from wide to narrow stereo, but it's very subtle, and my hearing isn't that great anyhow.

Now, back to the topic at hand, I do hear a lot of "whine", even on a warm engine when I rev it in neutral. It's done this for the last year/12K miles that I've owned it. I can only describe it as "gear noise". I think it's just the camshafts. A 32-valve QOHC engine is going to be noisy. My cold noise sounds more like a dentist drill, and I do think is related to air injection. I have a friend with a Roush Mustang and you want to talk about some noises, that thing can be hear a block away with all of its supercharger whine and valve slapping.

Glyn M Ruck

There is certainly an inherent whine in all Benz powertrains. I find it much lower on my M272 engine than it was on the M112 which is sohc by definition. My C240 always had a whine to it which remained consistent through the 8 years I owned it from new.

Rudeney

Alright, I hope I'm just chasing ghosts, but I have some noises that sound suspiciously like the pilot bearing failure in those videos. I had new tires put on yesterday, so today, I drove around with the radio off, top up, and A/C fan on low speed so I could listen for any noises. I noticed a distinctive whirring sound, but mostly only at idle (or at low acceleration, or coasting to a stop). When driving, I don't hear it. I really don't recall hearing this before, but I can't be sure as I rarely drive listening for noises like this. Are there any other symptoms or checks for the bad pilot bearing problem? Maybe I should just go ahead and replace the torque converter, or is there any harm in just waiting on it to fail?

Glyn M Ruck

Rodney - I would not go replacing torque converters until sure. My personal experience with this TC/Pilot shaft bearing/seal failure has been on AMG models in SA that have been driven hard. We have not experienced the US level of failures on other models. Now, that said, MBSA has always insisted on the full fluid & filter change EVERY 60,000 Km's - 39K miles. The cars are all under Motorplan (Mobilodrive) so this gets done. We have not had the MBUSA filled for life, change once at 39K miles nonsense.

The failures that I have personally experienced have started with that terrible loud whine in the clip I posted at start up after standing for a while. It then shuts up after the transmission fluid pressure come up. Over time the whine is there for longer & longer until it becomes constant as in the clip & blows seals etc. In most failures on this board the noise has appeared overnight & been constant. Possibly due to lack of servicing.

So I would let it develop a little to make sure you have the problem. The only downside to leaving it is that if left too long it takes out the transmission oil pump as well & frequently blows seals leaving you stranded with transmission fluid all over the place.

Good luck!

Rudeney

Well, if it's going to go wrong, it will happen to my CLK! Other than the whine, I have no other symptoms. It's fairly uniform cold or hot. Like I said, it;s most noticeable in neutral when revving the engine , or in drive right idle and very low RPM. I think the noise is coming more from the camshafts rather than the bell housing, but it's hard to tell. I need to get a stethoscope and check for sure. Anyhow, pulling the transmission to replace the TQ doesn't look too easy, so I'm just going to drive it. If it blows, it blows.

Nink

My CLK 550 just started getting a slight whirr noise between 12K and 20K RPM I am worried it is the dreaded balance shaft on M272 at 20K the noise of engine either drowns out the other nose or it goes away then returns as I decelerate, Advice ? 64000klm

Nink

OK Some more information its a 2007 CLK550. I turned the Airconditioner off so I could hear the noise better (Its been really hot and I drive with Aircon on max and the roof down - is there any other way :-) and suddenly the problem went away. I turned the aircon back on and a few minutes later the noise came back. Turned it off it went away. So I am thinking its aircon related at around 15K RPM and the noise of the engine drowns it out. Any ideas ?

Thanks everyone.

Rudeney

Nink, if you'll post your VIN, we can check your engine serial number to see if it falls within the range of those with bad balance shafts (or in your case, timing gear). The symptoms of a bad timing gear are generally not noise related. Instead, you'll get a MIL (check engine light) illuminated and the DTC's will be 1200 and 1208. I had no sound out of mine until the MIL was on steady for a month, and then I could really only hear it at idle from the front of the engine. It was a definite "chain slapping" sound.

As for your sound, I think you are off a bit on your RPM's - you engine redlines under 7K RPM, so you aren't operating at 12K-20K RPM. Maybe you mean 1,200 to 2000 RPM? The A/C compressor can be noisy - mine is. I can even feel some vibration in the steering wheel when it's running. I tend to think it's normal, but it could be a sign of premature bearing failure on the compressor. In your case, with the sound only presenting itself with the compressor running, I'd think it would be in the compressor itself and not the pulley/clutch bearing (since that's rotating all the time, A/C on or off).

Nink

Hi Rudeney thank you for the detailed response. I really appreciate how you volunteer your expertise I read a lot of your posts and they have solved a lot of problems for me. Your right i did mean 1200 RPM not 12000 :-). The AC still works fine so cant be lubricant / coolant and it definatly goes away after you turn it off so i guess your right the bearings inside compressor. I am the only one who notices the noise as its not that loud just not normal.

Should i replace compressor now or wait till it goes.

The VIN is XXXXXXXXXXXXXXXX (Deleted VIN) Thanks Rudeney

Rudeney

Nink, your engine is serial number 101576, which is well beyond the affected range, so no worries there!

Nink

Well the check engine light just came on asked the mechanic and he said time to worry.

Nink

Didn't believe him found a coupon for a free code reading. Took it to second mechanic and he said p0012 retarded camshaft sensor. He said parts are expensive go see mercedes as he couldn't get it any cheaper. Was a really nice guy

Rudeney

P0012 = DTC 0272, which is part of the TSB, but it's not a bad balance shaft; it's just the bad camshaft sensor. It's not very expensive and a fairly easy DIY, or, you might see if the dealer will get MBZ to "goodwill" the repair since it's a known defect.

Nink

Thanks Rodney 2 magnets cost me $83 at Benz in Markham Canada. About the cost of tank of gas

ALLDATAdiy INFO

You can find the latest TSB's in Alldatadiy.com Good Luck!