OM651 timing chain replacement

[supermonkeyman]

Hi guys, need your advice:

My engine was making a rattling noise when its was first started in the morning for a few seconds. The car has 70k miles and is only 4 years old.

Took it to my local dealership who initially couldn't hear the noise, went the next morning to have a look with a senior tech and he agreed it was there. They agreed that the timing chain, and tensioner etc may need replacing but isn't sure until the engine is stripped - face enough. Stripped the engine and have been told that the total cost of the work is almost £3000, MBUK are prepared to contribute £1000.

I've attempted haggling with them and the bill now is £2500 of which they'd like me to pay £1500. Ive also been told that if i don't agree to have the work done then the bill for me is still £1500 because its all the labour for removing and refitting the engine. The dealership have suggested that the cause of the fault is usually the oil not being changed at the recommended intervals and its seen on high milage taxis but the car has full MB history with the correct oil changes.

Any advice is much appreciated!

 

[supermonkeyman]

Spoke to customer services, all sorted!

 

[geraldrobins]

Glad to hear you have a satisfactory outcome.
Did they tell you the probable cost before the engine was stripped?

 

[grober]

OM651 timing chain issues surfaced fairly early in the service life of this engine after its introduction. This compounded by it being single chain and located at the rear of the engine . [ allegedly for under bonnet packaging issues linked to safety legislation] The oil change issue is probably corporate bull**** since many early engines exhibiting failure had been serviced according to manufacturer recommendations*. Several aspects of timing gear components were changed to counteract this but the inherent weakness / disadvantage of the design remains. Not good news for the users of this almost ubiquitous engine in the Mercedes car and van range. Glad you got the problem sorted to your satisfaction.

* If I was to guess the most likely cause of premature failure it would be the frequent use of high engine revs.

https://www.mbclub.co.uk/forums/gen...earing-worrying-things-250-diesel-engine.html

 

[190]

MB's oil change intervals are not necessarily optimised for the life of the engine. They also want to make the vehicle look cheap to service for fleet customers so perhaps the interval is a compromise. Private owners can improve on that compromise at very low cost by changing the oil more often.

This next bit is pure speculation.

I have to wonder how good MB's own oil is when it's being sold so cheap. It meets the specs so I suppose it must be good but is it the very best available ? What ever the best oil costs it's cheaper than changing cam chains.

 

[SMS]

Didn't read the link about high revs and chain wear, I would have thought stop start technology has something to do with it. The chain will snatch on start up and stopping of the engine.

 

[supermonkeyman]

I still have to make a sizable contribution towards the costs but that seems reasonable as the car is out of warranty.

Nope, they refused to give me an estimate for the repair until the engine was stripped. I did expect a large bill but expected goodwill to cover the majority if not all.

I'll post the figures once it's all been fixed and the figures are confirmed.

 

[SMS]

£1500 contribution? That's more than the complete job would cost at an indie.
The timing chain can be done with the engine in situ.

 

[supermonkeyman]

Yep I thought it was a bit excessive too for them to take engine out for that. Called Wayne Gates (I think) and they advised that they could do it for 1k and they'll need the car for only 1 day. That's a huge difference compared to 2800

 

[grober]

 

[supermonkeyman]

Ended up paying £1400, not too impressed with that