OM651 diesel engine

[Doggydoggen]

how much it costs in England to replace the timing chain at a car dealership?
I'll check what it costs in Sweden, but I'm afraid it's extremely expensive

 

[swifty]

Should I replace?

Hi guys,
My OM651 (220cdi) has now done 76000 mls, do you think I should have the timing chain changed as a matter of course just to be on the safe side? I don't think my engine has a rattly chain but all this talk of sudden failure has got me worried. Would anyone have an idea of the cost of replacement please?

 

[star]

Hi guys,
My OM651 (220cdi) has now done 76000 mls, do you think I should have the timing chain changed as a matter of course just to be on the safe side? I don't think my engine has a rattly chain but all this talk of sudden failure has got me worried. Would anyone have an idea of the cost of replacement please?

We haven't had one fail yet even one with a broken cam sprocket, so if you can hear a rattle on stat up, don't worry.

 

[Uncle Benz]

We haven't had one fail yet even one with a broken cam sprocket, so if you can hear a rattle on stat up, don't worry.

Similar experience here, haven't had one actually break. You'll get plenty of warning it's getting bad beforehand.

 

[swifty]

Thanks for the replies guys, as long as I am forewarned then I feel reasonably safe. I think I can distinguish a timing chain rattle. Most folk say that diesels are noisy when cold and sound better once warmed up but my car seems to be the opposite, it sounds great when cold and a bit "chattery" after a motorway journey. I assume this to be injectors (which were replaced by MB recall) about a year or so back. I know it's like asking "how long is a piece of string? but is this rattle more likely to timing chain or injectors please?

 

[Jeeringtowser]

M271 Sprocket Timing Chain Problems

Similar experience here, haven't had one actually break. You'll get plenty of warning it's getting bad beforehand.

Does the M271 engine give warning before a failure?
Regards
Chris

 

[star]

Does the M271 engine give warning before a failure?
Regards
Chris

Yes, the same rattle on start up.

 

[Jeeringtowser]

Death Rattle

Yes, the same rattle on start up.

Many thanks for that.
Regards
Chris

 

[Uncle Benz]

Yes, the same rattle on start up.

Agreed. We have seen a few of these actually fail, although not with a snapped chain, but jumped and bent valves. Twice we have seen them jump while cranking, and once where a mechanic in the neighbouring village was replacing the drivebelt and turned the engine backwards, via a spanner on the crank pulley bolt to aid the belt fitting. He heard a "click" but thought nothing of it. He then cranked the engine over with the key and bent the valves. Oh dear!

 

[ALFIEBEARD]

Agreed. We have seen a few of these actually fail, although not with a snapped chain, but jumped and bent valves. Twice we have seen them jump while cranking, and once where a mechanic in the neighbouring village was replacing the drivebelt and turned the engine backwards, via a spanner on the crank pulley bolt to aid the belt fitting. He heard a "click" but thought nothing of it. He then cranked the engine over with the key and bent the valves. Oh dear!

That brings back memories ..in the late 1970s I was adjusting the points on my girlfriends Hillman Avenger 1500 and rocked the car backwards and the same happened to me but luckily it only jumped one tooth causing it to run rough.
Since then I never rocked any engine backwards, as you effectively go against the tensioner if the chain/sprockets are worn.

Alfie

 

[star automotive solutions]

This is one I recently done that had broken the guide and taken 12 valves with it

 

[star automotive solutions]

Broken guide


Sent from my iPad using Tapatalk

 

[hod05]

We haven't had one fail yet even one with a broken cam sprocket, so if you can hear a rattle on stat up, don't worry.

Hi I've posted here before about a year ago I had the tensioner fail and had the rattle on startup happend in my last month of used approved warranty so was fixed by dealer apparently with updated unit.

They also state on invoice that they checked the chain and was ok but iv done 20,000 miles since and am considering changing the sprockets, chain and tensioner now as im approaching 90k how much would it cost roughly by indie to do this? Is £1500 a good estimate?

 

[ajlsl600]

educate pedestrians to LOOK for cars before crossing roads etc and that the PAVEMENT is for pedestrians, the roads are for CARS

after all, i dont see many 'pedestrian friendly' shaped buses, HGV's etc

damn right there sir.

 

[Robuk22]

Quote That's the strange thing, I have done timing chains and water pumps on this engine as low as 80,000 miles. Some have been that loud on start up after an oil change that I had feared it would snap. And yet some do much larger miles and have no problems at all. I have wondered if the stop/start system increases wear on the chain. Quote

OLD TREAD I know, but that is my exact thought, 600,000 starts against 60,000. I disconnected the stop start function immediately I purchased my 2012 M271 engined C-Class. Unplug the sensor attached to the negative clamp on the starter battery, no lights on dash, stop/start stays yellow (off), you loose brake hold, other than that car drives as normal.

 

[Robuk22]

To add to post above, I believe the chains in the M271 engine don`t break they elongate with wear on the links, the tensioner is then taken to it`s maximum limit and cannot tighten chain, the slack chain rides up the timing gear teeth and wears them down then jumps those worn teeth especially at startup, looses timing then Bingo, bent valves, new tensioner, new actuators, new chain if you are lucky. Don`t leave it, if it rattles at startup get it checked out, £100 or so for inspection is better than £2-3,000 for repair or a trashed car if the engine is not repairable. More repairers are questioning the stop/start system in relation to these earlier timing chain/gear failures.

 

[ajlsl600]

Seems Mercedes have not resolved their recent M271 timing chain issues with the new oM651 engine.

This is with the tensioner still in. Note the pile of chain on the right side of the picture.

we need to get american about this and related issues. this is a not fit for purpose issue ,as is Plasticine timing gears. right now some legal P in benz has calculated that its cheaper to fight/argue individual cases than to implement a fix.

 

[Robuk22]

Found this link on Piston heads, stop/start is mentioned again, most of the high mileage cars that don`t suffer early timing chain problems appear to be pre Blueefficiency stop/start cars.

https://www.pistonheads.com/gassing/topic.asp?h=0&f=96&t=1659383&i=20

 

[Botus]

stop/start is mentioned again,

when ever one see's stop start in relation to a car it should be always be interpreted as:

"we stop the engine so you have to start saving for a new engine / car"

 

[malcolm E53 AMG]

Well conversed with timing chain rattle on start-up going back a few years my Triumph Dolomite Sprint needed a new duplex chain every 20k miles when it need changing it sounded like the household cavalry coming down the road first thing in the morning oil starvation was the problem in this case.

if it rattles on start-up better to sort it sooner than later as most engines bend valves nowadays if the chain goes, replacement of tensioner, chain and sprockets are the best solution if you intend keeping the car long term