Thanks for that

I too thought chains far better and got a same car on 114000 with no probs.

i wondered if i changed also the tensioner it may help as wouldnt the push on it be a bit stronger, it seems to be the cam and crank sensors are mismatched when the ecu tries to time the engine correctly or that was my garage chaps reasoning.

No noise on engine when start up or running , smooth and refined.

You get so many opposing theorys online you dont know which to think right, Some say get rid asap others its fine just leave it, Very little info on W169 and this problem even on that loftys website the expert, even he has no page on this problem.

seem the larger V engines suffer more and some responsibility was taken by MB years ago its too late now for the cars who problems now start , low milage but over many many years.

Edited by martin blackett on 28/07/2018 at 12:45

I think I would be inclined to leave it alone. The car is not worth a lot,so investing money into repairs that will make little difference to its running is pointless. It's engine out for most things on these A -class models,even changing a starter motor (using MB method)

For anyone this may help.

i had a thought that if chain was sloppy or loose or strectched as the experts told me and this had caused the P0016 correlation code maybe a new tensioner would help.

Removed old one as on A class W169 petrol its an easyish job with a compact socket set.

Put new one in and cleared codes, ran engine started stops and magic, no faults.

The old units plunger was siezed solid as a rock, this with 69000 genuine miles and full MB histiry.

Remember to remove the top sealing cap on your old tensioner as for some reason the FEBI one i got had a cap over that i thought was a seal. How wrong i was. . on start up the oil pressure blew 1/2 gallon new oil all over drive., was told they are all supplied like that but have no mention of needing to use old seal bolt on the fitting instructions. madness ! why not supply a ready to fit unit, its a simply small bolt you screw in the top.

So there you are, a fixed Merc.

Edited by martin blackett on 01/08/2018 at 08:29

yes think you right there, live and learn inthe car trade

Probably a worn 'stretched' (elongated) chain. Nissan Almeras had that problem 10yrs ago. Disgraceful that MB has same. Shouldn't affect performance greatly unless EMS puts it into limp mode or something..... That's why so many chain designs for larger engines have an intermediate sprocket to avoid very long chains. But then that's just another bearing to fail....viz. Porsche Boxter. Belts are better now!

Thanks for info John

Do you think maybe a bit thicker oil would help take up a bit of play, maybe clutching at straws but just a thought, it runs on 0/40 Mobil done at dealers from new.

I doubt it, but as the elongation is caused by multiple microscopic increased play in the worn chain links and rollers (it doesn't actually 'stretch') it might be worth a try. At that mileage I can't see that 10-40 would hurt.