M271 When timing chain sprockets have been revised by Mercedes

[Js1200]

I'm trying to find Mercedes document with information when timing chain sprockets have been revised, hardened and improved by manufacturer on m271 engines.
I'm looking for dates and VIN numbers. Does anyone know that document or can point to official information?

 

[W1ghty]

I'm trying to find Mercedes document with information when timing chain sprockets have been revised, hardened and improved by manufacturer on m271 engines.
I'm looking for dates and VIN numbers. Does anyone know that document or can point to official information?

What year is yours buddy ?

 

[Js1200]

What year is yours buddy ?

I haven't got w204 yet but I'm looking for one.

 

[markjay]

The M271 engine on the W204 generally suffered from a leaking hydraulic tensioner, which is different to the sprocket wear issues of the early M271 engines.

What happens when the hydraulic tensioner leaks, is that it doesn't hold the oil when the engine is switched off, and therefore every engine start is a 'cold' start as far as the timing chain is concerned, leading to premature timing chain fatigue and eventually to the dreaded jumped tooth.

This particular fault does not happen without warning, though, you'll hear the chain rattle on every engine startup (i.e. not just on a cold start), but it does happen much earlier and has been reported on engines as 'young' as 30,000 miles.

Personally , I would steer clear of any car with the M271 engine, unless you're happy to get the timing gear sorted for peace of mind as soon as you buy it. If budget permits, I would look at W204 cars from 2012 onwards, that will have the M274 engine. It does have a potential issue with the thermostat, but even if this happens it won't kill the engine like a timing gear failure does.

 

[markjay]

The thing is that the early M271 engines typically only failed at around 100,000 miles, so until a few years back it was fine buying a W203 with say 50,000 on the clock, knowing that the car still had a few years of reliable service in it. But these days you'll struggle to find a W203 with genuine low mileage. The W204 sadly never enjoyed this 'grace' period, with the timing chain failing much earlier, making a second hand buy risky from the get-go (unless there's documentrd proof that it has been repaired). The combination of these two is why I would say that at this point I would no longer buy any car with the M271 engine. Which is a shame, it's a rather good engine otherwise, a very lightweight DOHC 16V engine with a potential factory tune up to 201bhp (in the C250 CGI), what's not to like?

 

[W1ghty]

The thing is that the early M271 engines typically only failed at around 100,000 miles, so until a few years back it was fine buying a W203 with say 50,000 on the clock, knowing that the car still had a few years of reliable service in it. But these days you'll struggle to find a W203 with genuine low mileage. The W204 sadly never enjoyed this 'grace' period, with the timing chain failing much earlier, making a second hand buy risky from the get-go (unless there's documentrd proof that it has been repaired). The combination of these two is why I would say that at this point I wouldn't buy any car with the M271 engine.

I hope my M271 doesn’t hear all this negativity buddy

 

[markjay]

I hope my M271 doesn’t hear all this negativity buddy

Well, it's a statistical risk.....

My grandfather smoked a packet a day from when he was 16 till he passed away at 82 from old age, and he was the healthiest person I knew...go figure.

 

[markjay]

Well, it's a statistical risk.....

My grandfather smoked a packet a day from when he was 16 till he passed away at 82 from old age, and he was the healthiest person I knew...go figure.

But I would get those sprockets inspected....

 

[Wyliematt]

Hi all hope don’t mind jumping in here and new to this club
I have a 2009 M271 engine with slight engine noise on start up sounds like tc tensioner it’s the 204 engine so stripped down yesterday no slack in the chain and timing was spot on.
So fitted a new tensioner as the old one was I think shot on inspection very weak.

Just carried out my cold start test noise is still there ? Is there anything else on this engine that can sound like a tensioner or do you think all the chain etc needs changing as look good on inspection? Cheers

 

[markjay]

Hi all hope don’t mind jumping in here and new to this club
I have a 2009 M271 engine with slight engine noise on start up sounds like tc tensioner it’s the 204 engine so stripped down yesterday no slack in the chain and timing was spot on.
So fitted a new tensioner as the old one was I think shot on inspection very weak.

Just carried out my cold start test noise is still there ? Is there anything else on this engine that can sound like a tensioner or do you think all the chain etc needs changing as look good on inspection? Cheers

Welcome.

Can you identify if the noise is coming from the front end (timing chain), or from the top end (hydraulic tappets and valves)?

Also, what engine oil do you use, and when was it last replaced?

 

[Wyliematt]

Welcome.

Can you identify if the noise is coming from the front end (timing chain), or from the top end (hydraulic tappets and valves)?

Also, what engine oil do you use, and when was it last replaced?

Hi and thank you

Welcome.

Can you identify if the noise is coming from the front end (timing chain), or from the top end (hydraulic tappets and valves)?

Also, what engine oil do you use, and when was it last replaced?

 

[Wyliematt]

Hi and thank you for reply.

Well the noise is not as load as when I done the tensioner on 1st strap up can hear more inside and it seems to be top of engine or rear as can hear in cab. It doesn’t sound like the chain flapping just more of a noise if chain is very slightly loose.

oil and filer done about 300 miles ago 0/30 and Bosch filer

 

[W1ghty]

Well the noise is not as load as when I done the tensioner on 1st strap up can hear more inside and it seems to be top of engine or rear as can hear in cab. It doesn’t sound like the chain flapping just more of a noise if chain is very slightly loose.

oil and filer done about 300 miles ago 0/30 and Bosch filer

What’s the mileage buddy ?
Isn’t the recommended oil 5w40

 

[Wyliematt]

What’s the mileage buddy ?
Isn’t the recommended oil 5w40

Hi fella.120k ..with full history up to 3000 miles ago.
Funny you should say that I did check on line and oil data at friends work shop says 5/30 0/30
So put the 0/30 in . Bit thin!
I was thinking shall I use different oil
Would you recommend it
Has brand new tensioner now so was surprised to hear that this morning unless it’s something else.

 

[W1ghty]

Hi fella.120k ..with full history up to 3000 miles ago.
Funny you should say that I did check on line and oil data at friends work shop says 5/30 0/30
So put the 0/30 in . Bit thin!
I was thinking shall I use different oil
Would you recommend it
Has brand new tensioner now so was surprised to hear that this morning unless it’s something else.

For the few quid it costs , might be worth seeing if the 5W/40 (MB spec 229.5) lowers the noise ?

 

[Wyliematt]

For the few quid it costs , might be worth seeing if the 5W/40 (MB spec 229.5) lowers the noise ?

Thank you for your info I will be doing that for sure. Like I said I’ve 90% cured it with tensioner just baffled as to why the tensioner is still loosing a tad of pressure,if it’s that? Will do oil hopefully will work,it has to be something like that now.
Thanks again bud take care

 

[Wyliematt]

Thank you for your info I will be doing that for sure. Like I said I’ve 90% cured it with tensioner just baffled as to why the tensioner is still loosing a tad of pressure,if it’s that? Will do oil hopefully will work,it has to be something like that now.
Thanks again bud take care

Hi …
Just to let you know I done the oil with full merc oil and spec. Noise still there and even does it now after couple of hours but it’s spit second sort of thing.New tensioner as well.any ideas? When running after couple of seconds she is sweet and quite? Not a noise at all.
It has to be oil pressure related as I disconnect engine from firing up crank her for say 10seconds reconnect ignition and fires up with not a peep from engine. Any help cheers

 

[mg1pa1]

not wishing to hijack the thread - i believe it all related! my 2004 C180k started running like a dog overnight - misfiring and hesitation below 2000rpm and at idle (seems to run fine under load and above 2000rpm). Engine light has come on a couple of times since but the only CELs i am getting are misfires on cylinders 1 to 4 i.e. all cylinders. I have checked a few things but lastly i inspected the timing. With the crank at TDC, the exhaust cam appears to line up but the intake cam looks to be advanced by 1 tooth. It looks like it has jumped a tooth and i suspect this could give rise to the hesitation and misfiring i am experiencing. The car has done 235k miles and id love to save it from the scrap yard - it has been a fine car in every other respect and never let me down. What i am struggling to diagnose is what has caused it to jump a tooth. My understanding from reading posts like this, is the culprits are several. 1. a stretched chain, 2. worn/defective cam adjuster, 3. worn/defective tensioner, and/or 4. worn guides.
The chain was incredibly taut across the top guide between cam adjustors - no play at all but the slack may be elsewhere in the chain, i dont know.
I turned the crank a full turn and inspected the teeth on the cam adjustors/sprockets - no missing teeth and they appeared uniform in my non-professional opinion.
I removed the cam magnets and using a 27mm socket i tested for free play - i'd say there was little to no play, maybe 1mm on each.
This leads me to rule out the cam adjustors (although i believe the symptoms im experiencing match the issues caused by a failing cam adjustor).
I dont know how i can check for chain stretch without removing the lower timing chain cover which im not looking to do.
I dont know how one would go about checking the guides without removing them - do worn or failing guides give any specific symptoms? I'm comfortable replacing the guide on the exhaust side but the inlet side guide requires the lower chain cover to be removed which i wont be doing. As this is a difficult/time consuming one to remove, my guess is if a guide is worn, it will likely be this one.
I was thinking of buying an endoscope to try and check out the tensioner. I expect all this will reveal is to what extent the tensioner is extended. A fully extended tension may suggest the chain has reached its limits.
My biggest concern here is that i go to the effort of replacing the chain, tensioner, adjustors and 2 of the 3 guides, only to find that it is the last remaining guide which is defective and causing issues. Does anyone have experience of this? Is the lower guide susceptible to wear? Just canvassing opinions prior to deciding what to do. If i dont proceed, it would make a great car for someone who has the ability to do the job in full or indeed, a parts car (sigh).