Timing chain tentioner location C250 cgi

[David Wheller]

Can somebody please advise of the location of the timing chain tentioner on a C250 cgi W204 (2011) please.

Thanks in advance

 

[Tony Dyson]

Hello David, I believe your engine is the 2148cc type 646, please find herewith a couple of pictures from a Haynes Manual to assist.

 

[David Wheller]

View attachment 48994 View attachment 48995

Hello David, I believe your engine is the 2148cc type 646, please find herewith a couple of pictures from a Haynes Manual to assist.

Tony, many thanks for the prompt reply.
Unfortunately that is not my car.
Mine is the 1.8 petrol turbo version, I believe the one you've said is the diesel.

Having said that are they very similar engines?

 

[Tony Dyson]

Aah, I thought your CGI ref was a typo, sorry I cannot help with your petrol engine but I'm sure someone will be along soon who will.

 

[David Wheller]

Aah, I thought your CGI ref was a typo, sorry I cannot help with your petrol engine but I'm sure someone will be along soon who will.

That's ok, thank you

 

[LostKiwi]

This may help:


If you are replacing it because you have a noisy timing chain check all the pulley at the top of the engine. The M271 has issues with timing sprocket wear which can get to the point where the chain jumps teeth causing major internal damage. If you get timing chain noise on the first start of the day have it checked as soon as possible.

 

[malcolm E53 AMG]

It would appear to be at the front of the engine which is a M271 direct injection unit

http://www.motorreviewer.com/engine.php?engine_id=37

 

[David Wheller]

This may help:
View attachment 49000

If you are replacing it because you have a noisy timing chain check all the pulley at the top of the engine. The M271 has issues with timing sprocket wear which can get to the point where the chain jumps teeth causing major internal damage. If you get timing chain noise on the first start of the day have it checked as soon as possible.

Hi, mines a strange one.
There is no adverse noise upon start up, the noise starts when on tick over / idle.
Upon pressing the accelerator pedal the noise stops.
It's as tho there is no oil getting up there.

I spoke to a friend, who's a BMW mechanic and he believed it to be possible the tentioner

 

[David Wheller]

Also does anybody know if there is a workshop manual for this vehicle, as I'm struggling to find one

 

[LostKiwi]

If your engine is an M274 the tensioner will be in the same general area - left side low down looking from the open bonnet.
You can tell which it is from the engine number. First three numbers are engine family, next three are variant and the remainder serial number.
For example 119027123456 is an M119 variant 027 with 123456 being the serial number

 

[LostKiwi]

I'm not aware of any manuals.
You can get copies of the Mercedes WIS (Workshop Information System) on eBay.

 

[David Wheller]

I'm not aware of any manuals.
You can get copies of the Mercedes WIS (Workshop Information System) on eBay.

Thank you

 

[star]

Chain tensioner is behind alternator but it doesn’t sound like a chain noise, more like a sprocket problem.

 

[David Wheller]

Chain tensioner is behind alternator but it doesn’t sound like a chain noise, more like a sprocket problem.

As in the adjusters at the top ?

 

[LostKiwi]

As in the adjusters at the top ?

The two round toothed bits at the top in that diagram I posted.
Pull the cam cover off to visually check their condition.

 

[star]

Variable cam sprockets.

 

[David Wheller]

The two round toothed bits at the top in that diagram I posted.
Pull the cam cover off to visually check their condition.

Ahhh yes, the expensive parts lol

 

[LostKiwi]

Ahhh yes, the expensive parts lol

Not half as expensive as the bits they destroy when it all goes wrong!

 

[David Wheller]

Not half as expensive as the bits they destroy when it all goes wrong!

Very true, but wouldn't they also make a noise upon acceleration?

 

[star]

When they fail internally rather than wear, you won’t see anything.