200 PSI Compression Test.
Did you hear some noise at startup with the old chain/do you still hear it with the new chain?
Hmm, maybe the chain had been replaced before, who knows.
The camshaft sprockets can still get eaten though. Did you examine them for wear?
I really believe the M271 chain could last the life of the vehicle, with proper mx and the correct oil.

The oil on your plugs concerns me but I'm confused about the "golden" oil? Had you just had an oil change? I would not expect any oil but certainly not that color! Seriously oil fouled plugs would tend to cause misfires and you don't mention that (I assume that would throw a CEL, too). I would also expect the wrench who did the compression test to comment on the oil, but from your post, he didn't seem concerned. A leak down test would determine whether your rings or valve guides are worn. Are you having problems with the engine? Is it burning oil, running rough, etc.
Did you hear some noise at startup with the old chain/do you still hear it with the new chain?
Hmm, maybe the chain had been replaced before, who knows.
The camshaft sprockets can still get eaten though. Did you examine them for wear?
Thanks for the reply. Nope, the water pump was not leaking. I just told the technician to replace it for general purpose, including the thermostat, serpentine belts, etc. Funny he showed me my A/C compressor pulley was somehow noisy so I called the dealer and they said it will be $230 for the pulley and the whole A/C compressor is almost $900. So I called different places and I found a Denso A/C compressor for my C230 for only $430. So I got a new Denso compressor, new condenser with filter dryer attached to it and a new radiator.
Regarding the chains, it's never been replaced. I asked the full history of my car from El Dorado Mercedes dealer and they were so nice to grant my request. The previous owner meticulously took care of this car and never brought this car to any shop except the dealership somewhere at the bay area. We also compared the old and new camshaft sprockets and no difference at all. So I decided to return them and just use the old to save some money. Now two of my chains are new too (upper and lower). About the start up noise, I didn't hear any chain noise before. In fact, it just sounds same to me before and after chains replacement.
The oil on your plugs concerns me but I'm confused about the "golden" oil? Had you just had an oil change? I would not expect any oil but certainly not that color! Seriously oil fouled plugs would tend to cause misfires and you don't mention that (I assume that would throw a CEL, too). I would also expect the wrench who did the compression test to comment on the oil, but from your post, he didn't seem concerned. A leak down test would determine whether your rings or valve guides are worn. Are you having problems with the engine? Is it burning oil, running rough, etc.
The technician that worked on my car told me that the previous tech at the dealer spilled some oil to the first two spark plug holes during oil change. Burning oil, not sure yet cos I just got the car last June. No CLE and the engine runs smoothly, better than my 2014 Corolla with 5k miles on it.
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I really believe the M271 chain could last the life of the vehicle, with proper mx and the correct oil.
I agree.
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This is a known issue. It is not a maitenance or neglect problem.

This is a known issue. It is not a maitenance or neglect problem.
According to the Russian service people.
(http://www.benzclub.ru/forum/showthread.php?t=207658)
The chain + tensioner, and then you check the sprockets and replace them if they are worn (~$1500 for two
)

Apparently, the ROW M271 engines made in 2006-7 suffered the same soft metal problem as V6's in the US. So - faulty oem parts.
See https://mbworld.org/forums/5127938-post143.html
The guides may wear out if the chain slaps them when stretched, per Glyn.
This is a known issue. It is not a maitenance or neglect problem.
I agree Matt. Both you and I maintained our vehicles obsessively, and yet look at the range in miles of both our cars...mine likely stretched at 99K miles, and yours making noises at 145K miles. Other than that, like you said, our cars look fantastic. And there is no way that 99K miles is considered the life of this engine. Our vehicles have been maintained exceptionally, and quite often, taken care of FAR better than what Mercedes would take care of based on their maintenance schedule (an example would be doing 8,000 mile oil changes instead of Mercedes' recommended 12,000 mile changes).
According to Glyn, over in SA, there has been an epidemic of these chains stretching.
Cintoman

I don't think MB considers the timing change to be a real issue.
Sorry for my late reply. I'm busy with my NP program. Anyway, my car runs perfectly fine. I already put 5k miles on it since I replaced my timing chains. Plus I had my other seals (main seal, transmission seals both front and rear) replaced too. Drained my torque converter while my tranny was out of the car.
Funny though because I bought 6 Liters of Mercedes Transmission fluid (red) from the dealer. While putting them in my car, we wondered why one of the bottle has blue oil
. We checked the label at the back and it says 236.15. So I called the dealer where I bought these oils and they were very helpful. They gave me 12 Liters of 236.14 red oil in an unopened box, transmission filter and a gasket to flush my tranny. Did the drain and refill 3 times and now my car has a complete clean transmission oil. I think Mercedes liked blue fluids for their cars. My Mercedes coolant is also blue.


