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I recently had the valve cover cover off my daughter’s 2003 C230 to replace the gasket since there was a small leak into the #1 plug. It has 125k miles.
I took the following picture of the timing chain and cam gears. The wear doesn’t strike me as unusual but I know a lot of people have had timing chain and gear issues. Does anyone see anything I should be concerned about?
The chain looks nice and tight in the photo. Out of curiosity, did you check how much stretch was in the chain?
Supposedly a major cause of timing chain issues is usage of incorrect engine oil, especially if it's the wrong grade (viscosity). I just passed 230k km on my original chain and the mechanic said my chain had plenty of life and minimal (some 4 degrees) stretch when I had it inspected at 180k. I've always only used MB approved oil.
Last edited by slammer111; Nov 14, 2019 at 01:03 AM.
If you still have the cover off, you can pull on the chain in the middle of the section touching the gear - you should not be able to pull any significant slack. If you do, there is a wear problem. Looking at the gear itself I doubt you will be able to. Chain and gears usually wear together.
I didn’t measure stretch but it is very tight. Everyone should check this if they have their valve cover off—it’s good to have a summary of what to look for.
I always use the recommended Mobil 1 oil. Once a year or 7500 miles, whichever comes first.
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Supposedly a major cause of timing chain issues is usage of incorrect engine oil, especially if it's the wrong grade (viscosity). I just passed 230k km on my original chain and the mechanic said my chain had plenty of life and minimal (some 4 degrees) stretch when I had it inspected at 180k. I've always only used MB approved oil.
On one of my rare visits to the dealer I had a discussion about maintenance issues with one of the parts specialists. He had previously been a mechanic.
He told me that most timing chain failures occurred because owners didn't change the oil at the recommended intervals. I cannot say for sure whether he was repeating Mercedes corporate propaganda or sharing information based on experience. He seemed passionate about the issue, so what you heard may be accurate and Mercedes is being criticized unfairly.
I have been scavenging parts from a C230 that had an engine failure. I'm assuming the car had a timing chain issue, but I cannot say for sure. The design does not appear to be robust and I can readily believe it is prone to failure.
My car is at 146,000 miles (roughly 235,000 km) so I am at almost the same mileage as slammer111. My regular independent mechanic has told me the chain sounds fine on start up. I received the same feedback from the local independent Mercedes specialist.
I want to keep the car indefinitely, so I may just have the job done. According to an email I received from CarFax.com, my car is worth $2300. I wouldn't sell it for that amount, but it does make it difficult to decide to pay $1100 to a mechanic to change the chain. I think the parts alone are in the $400 range.
I’d be inclined to wait until I start hearing the cold startup rattle. Then decide. It’s worthless if the chain breaks or skips. Keeping it going for $1100 may be ok if you really like the car.
My car has the “normal” from day 1 (I think I bought the car with less than 20 miles on it back in ‘04...I’d have to recheck.) lifter sound for a few seconds - but certainly no rattle or noise. Once it’s up and on it’s sewing machine quiet.
I’ve always changed the oil way before use, often by year time interval. I have brought the car up past 3,500 only a few times, honestly and blipped the clutch or stalled it out accidentally 5 or 6 times...
I’ve started it with the radio and HVAC off since first learning of this bad chain design...no difference in sounds.
That said, knowing the car is “worthless” to the outside world but means the world to me...maybe this summer I’ll look into changing mine...just because it’s been so good to me.
How sis the chain feel in terms of slack? It should be so tight you cannot lift or move it by hand.
While changing the valve cover gasket today, I tugged on the timing chain to get a rough idea on the amount of stretch. Based on what you can see on my video attached below, what do you guys think? It is still the original chain with 195,000 miles on it.
You can't tell anything by pulling in the middle, the tensioner keeps there from being slack between sprockets, you have to pull on the middle of the sprocket, if you can see a half a tooth the chain needs changing. That said, your sprockets are showing a little wear but not too bad. With that many miles, I would recommend planning a replacement soonish.
The easiest way to tell with the cover off is to rotate the chain until the camshaft notches are up top, then look at the timing marking on the crankshaft pulley to see the offset/stretch. According to my indie, 6-7 degrees is when it's time to replace.
I'm guessing no. A boroscope will be needed, and even then it may not work.
The cylinder positions will be tied to the crankshaft position, which you already know from looking at the pulley. You'd have to see both camshaft notches through the oil filler cap.
The easiest way to tell with the cover off is to rotate the chain until the camshaft notches are up top, then look at the timing marking on the crankshaft pulley to see the offset/stretch. According to my indie, 6-7 degrees is when it's time to replace.
Forgive my ignorance, but do you rotate the chain by turning the crankshaft pulley using a wrench? And this would require removing the intake resonator first to make some room, correct?
The crankshaft pulley can be accessed after removing the intake resonator and serpentine belt. My understanding is that it requires a 27mm socket to turn.
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