Potentially Expensive Engine Failure
Yesterday the car lost power and today failed to start.
The agents have just informed me that the timing chain and tensioner have failed.
The car had just had a service a few days earlier. The mileage is 65,000 miles.
My question is does this engine have an adjustable timing chain tensioner and is this a serviceable part that is adjusted at this service. I do have a concern that this part was incorrectly set at the service.
Thanking you
Antony
The question I have is, if it did indeed fail, did it damage the valves (a problem on some engines when the timing belt/chain fails and the pistons crash into the valves because they opened at the wrong time)?
They say the computer reading shows the valve timing to be 4 degrees out. According to the agents this is beyond the adjustable range of the variable timing so they say the chain has slipped.
All I know is that this is going to get expensive.
I also cant believe that i am the only one on this forum with this problem.
Thanks for your reply,
Replacement of the timing chain is not cheap, maybe 5-10 hours depending no the shop. I would want to know that the engine is not damaged first before spending that much $$$ on labour. A shop with a boroscope (sp?) could look inside each spark plug chamber and determine if the valves, pistons, and cylinder walls are damaged.
Moreover, have they popped the valve cover off to at least do a visual inspection of the head/valves? Any signs of oil sludge?
Any slippage/breakage on an interference engine will cause damage to the valves/head/pistons/crankshaft/block.
Chains/belts stretch as they age due to centrigual forces stretching the chain. On motor and mountain bikes, chain replacement is a common thing. When comparing against a brand new chain on a bench, the old one will have stretched.
What signs of failure did the tensioner show? Did the spring crack? Was the bolt loose?
This is probably an emotional time for you, and even more so your wallet. On every car i've had for a long time, Honda, Toyota, VW, + German marks, each has experienced some sort of low to mid 4 figure failure out of warranty and no goodwill. That's why used cars with factory warranty command a premium over out of warranty.
My advice, if the uncertainty factor of $$$ is stressing you out, mother's little helper always helps.


I've got an adapter that permits pressurizing the cylinder with compressor air by replacing the spark plug with this threaded adapter. Chances are that if the valves are bent, then non of the cylinders will hold air. No dissassembly required for this test...
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The chain and tensioner were replaced and a compression test was 100%. The dealer did not have a scope as has been suggested above.
fortunately the "Slack" chain only slipped a tooth and was therefore still intact. There seems to be NO valve or wallet damage. the cost was only $ 900.00 where I pay half.
My car is out of its warranty in 4 months so I just left the car at the dealer and bought a 2 year old E Class W211. It is a 3.2 cdi and goes like hell.
There WAS a Warning to this failure, on startup in the morning the engine was noisy for the first 4 seconds. I did report this to the agents one week earlier at the service, they said it was the hydraulic valve lifters and I can ignore it. Well guess what. I bet you the tensioner runs on engine oil and for some reason it was not holding its tension (Maybe some one can enlighten me if the tensioner runs on oil pressure).
So guys its a fond farewell from the W203 forum and off to the boring old man W211 forum for me.
Thanks for the support and please do not ever ignore a ticking sound at startup.
Bye for now
My only question is: can this be caused by water? I'm told by one mechanic that the supercharger sucked in water (I live in Miami. This summer has been very wet.) causing the issue. Then I'm being told by the dealer that no water was found. Again, can water cause the problem? Thanks.
My wife was actually driving the car and recalls driving through several puddles. She parked the vehicle at a local Starbucks, returned to the car and it wouldn't start.
It has been reported to my insurance company. The first opinion (personal mechanic) was that there was water. My second opinion was "no water". I'm arguing that by the time the second inspection was performed (approx 5 days later) the water had evaporated and therefore that is why no water was found upon the second inspection. A third opinion is not going to do me any good at this point. Let's see what the outcome is.
Hopefully your insurance will cover it as a comprehensive claim. I doubt they will repair the car depending on your mileage, I guess.








