2011 C180 starting glitch

[Swanseabay]

Hi Folks. New on here, with a query/problem. I have a low mileage 2011 C180 saloon (48000 miles) with a strange starting "glitch". Any diagnosis/advice would be appreciated.
Warm or cold it always used to start instantly, no messing. A few weeks ago, I noticed that, from time to time, usually when cold, there was a hesitation after the twist of the key: for a second or so there was a low (and not noisy) "Duh - duh - duh" before it burst into life. It's never not started and this only happens occasionally. However, days after the first time this happened, the engine management light came on, but after a few days, it went off again. As it was due for a service, I took it in (to my local independent Mercedes garage) for a B6 service. This was done, but it was suggested to me that my problem might be the TIMING CHAIN. However, I don't have any other symptoms, in particular there's no rattling or other noise from the engine that would suggest anything is amiss there. Does anyone have any insight into anything similar or any advice before I put it in the hands of someone to look at the timing chain - or whatever. Thanks.
PS I am retired and a relatively low mileage, fairly staid driver. I've had the car for about 5 years and, until the last service, it's been main dealer-serviced every time.

 

[malluboy77]

Here is what the timing chain issue sounded like on my S204 C250 CGI. Not sure if it was the inlet or outlet cam gear was gone.

Help please, start up noise on W204 C250 CGI

 

[Old spanners]

Hi Folks. New on here, with a query/problem. I have a low mileage 2011 C180 saloon (48000 miles) with a strange starting "glitch". Any diagnosis/advice would be appreciated.
Warm or cold it always used to start instantly, no messing. A few weeks ago, I noticed that, from time to time, usually when cold, there was a hesitation after the twist of the key: for a second or so there was a low (and not noisy) "Duh - duh - duh" before it burst into life. It's never not started and this only happens occasionally. However, days after the first time this happened, the engine management light came on, but after a few days, it went off again. As it was due for a service, I took it in (to my local independent Mercedes garage) for a B6 service. This was done, but it was suggested to me that my problem might be the TIMING CHAIN. However, I don't have any other symptoms, in particular there's no rattling or other noise from the engine that would suggest anything is amiss there. Does anyone have any insight into anything similar or any advice before I put it in the hands of someone to look at the timing chain - or whatever. Thanks.
PS I am retired and a relatively low mileage, fairly staid driver. I've had the car for about 5 years and, until the last service, it's been main dealer-serviced every time.

There may be some stored codes that would point to what the problem is, I would have thought the independent would have scanned when the service was done.
If not a session on STAR should show something if it's as major as a timing chain. I certainly wouldn't be changing the chain before there was some definite proof that was the problem. Could be something as simple as a battery.