Case study - OM651 turbo fault

[barian]

Do you think the timing chain problems might be related to the introduction of start/stop? Chains must be seeing a greater number of load/unload cycles, I suppose. When I mentioned the issue to the service foreman at my dealer a while ago he did say that the only cases they had seen were with private hire vehicles, and I wondered whether that fitted the theory.

 

[Uncle Benz]

Do you think the timing chain problems might be related to the introduction of start/stop? Chains must be seeing a greater number of load/unload cycles, I suppose. When I mentioned the issue to the service foreman at my dealer a while ago he did say that the only cases they had seen were with private hire vehicles, and I wondered whether that fitted the theory.

Interesting you should say that. Both the ones I've seen were taxis

 

[WG M-B]

all the same, i think we all agree that on what is, supposedly at least, a premium quality brand, these issues shouldnt really be occurring at all! Ford/Peugeot can make timing belts run in OIL and STILL last over 100k miles (change interval is recommended at 125k on mine for example) and yet MB are having troubles with chains/gears at sub 100k miles.

something isnt right somewhere!

I agree with you Pete.
But I haven't had one fail?
These engines aren't put together particularly well. Plastic sumps, oil coolers etc, but I have many running over 200k now like a clock.
I think maintenance is the key with all the modern diesels. Put crap oil in them etc and they aren't up to it!
I would buy a car with a 651 engine

 

[Uncle Benz]

I agree with you Pete.
But I haven't had one fail?
These engines aren't put together particularly well. Plastic sumps, oil coolers etc, but I have many running over 200k now like a clock.
I think maintenance is the key with all the modern diesels. Put crap oil in them etc and they aren't up to it!
I would buy a car with a 651 engine

In many respects it is a good unit - powerful, economical and quiet. The choice of materials and quality of build, however, would put me off ever owning one. That, and the fact that I have too much of a love affair with vee eights going on

 

[turbopete]

i have to say that personally i am a fan of the mercedes diesels as a general rule, BUT the 651 is 1 engine i will avoid like the plague! budget, and the fact that i would have been looking at 651 equipped cars, in a good number of cases, are the main reasons i didnt end up with a 204 Sport or a late 211/early 212.

id have really loved the 204 Sport with the 250cdi lump and manual box. in many ways its like that particular car was designed JUST for me! but until the 651 issues are resolved, or a more reliable engine comes along, i really cant see me getting another MB diesel for a while (and id miss the kick in the back from the turbo buying a petrol of the same era)

 

[CowleyStJames]

My 2010 2.0 Cdi Blue Efficiency running the OM651 has covered 138,000 miles and its still as sweet as the day it came out of the factory.
We have eleven Sprinters running same engine and mileage anywhere between 46,000 and 180,000 on our fleet in store and none have had timing chain issues.
All our vehicles and mine are regularly maintained with correct oils.
Perhaps the ones getting the issues are the vehicles not maintained correctly

 

[turbopete]

My 2010 2.0 Cdi Blue Efficiency running the OM651 has covered 138,000 miles and its still as sweet as the day it came out of the factory.
We have eleven Sprinters running same engine and mileage anywhere between 46,000 and 180,000 on our fleet in store and none have had timing chain issues.
All our vehicles and mine are regularly maintained with correct oils.
Perhaps the ones getting the issues are the vehicles not maintained correctly

the issue seems to be the lower mileage ones. your average joe, covering 10k per year, possibly in a city with stop start tech on the engine. people like me (i dont have one, but the useage is the same) a few miles to work each day, and a bit of a run (100 miles or so) every other weekend. its THOSE engines that suffer from the issues. the taxis/vans that run 12 hours a day, 6 days a week, 1k miles+ per week, no problem at all.

 

[Westheath]

Just look at the Vauxhall engines Z1.x XE/P

They have timing chain problems before they hit 40,000

But.............

Timing chain complete kits sprockets, guides, tensioner, crank seal, gaskets for
£45.00 makes it a cheap repair to carry out even after oil & filter coolant and run in time.

Its an under £200.00 repair.

 

[turbopete]

exactly. and it wouldnt be too much of an issue in the 651 engine, by all accounts IF they hadnt gone and put the timing gear at the BACK of the engine, instead of the front!

ive heard it was to do with the pedestrian safety regulations, but seriously, how much difference would raising the bonnet line at the front of the engine area by around 30mm (at a guess) make? or even make the mounts thinner to sit the engine slightly lower away from the bonnet to reduce the additional height required on the bonnet?

or simply put a duplex chain on. if i can work it out, sirely its not THAT hard for the boffins to work out, surely?

 

[barian]

the issue seems to be the lower mileage ones. your average joe, covering 10k per year, possibly in a city with stop start tech on the engine. people like me (i dont have one, but the useage is the same) a few miles to work each day, and a bit of a run (100 miles or so) every other weekend. its THOSE engines that suffer from the issues. the taxis/vans that run 12 hours a day, 6 days a week, 1k miles+ per week, no problem at all.

Except that the OP said that the two cases he had seen were both taxis.

 

[turbopete]

Except that the OP said that the two cases he had seen were both taxis.

they may well be local run, stop start type taxis. i was thinking more of the airport transfer type or the ones used rather like the london 'black cabs' where almost the only time the engine is switched off is to refuel or service.

 

[barian]

they may well be local run, stop start type taxis. i was thinking more of the airport transfer type or the ones used rather like the london 'black cabs' where almost the only time the engine is switched off is to refuel or service.

They may be, although perhaps we don't know. And I have yet to see any low mileage taxis, other than new black cabs. But your view that it is the low mileage vehicles that are susceptible is interesting. How many cases is it based on, may I ask?

 

[turbopete]

They may be, although perhaps we don't know. And I have yet to see any low mileage taxis, other than new black cabs. But your view that it is the low mileage vehicles that are susceptible is interesting. How many cases is it based on, may I ask?

just the ones ive read about here and other sites. the bulk of the ones having issues tend to be the ones that are started and shut down (engines) more, so cars with start stop, or the average person going to the shop/work etc rather than the ones running all day, like the long distance/out of town taxis, couriers (not the door to door parcel types but proper courierswhere a full van may be 1 or 2 deliveries) that sort of thing. as has been said by someone else previously, it does look like stop start (the eco system) could well be a problem in accelerating the issue.

 

[Uncle Benz]

they may well be local run, stop start type taxis. i was thinking more of the airport transfer type or the ones used rather like the london 'black cabs' where almost the only time the engine is switched off is to refuel or service.

Local village taxis. Not constant use at all. They are moving the fleet towards v6 diesel now - not enough mileage being covered to worry about the mpg difference. Also, not owner/driver cars. If it's bought with your own money you tend to have a little more respect for the machine. To give some idea, one of the drivers gets through brake pads four times as fast as the other drivers...

 

[turbopete]

Local village taxis. Not constant use at all. They are moving the fleet towards v6 diesel now - not enough mileage being covered to worry about the mpg difference. Also, not owner/driver cars. If it's bought with your own money you tend to have a little more respect for the machine. To give some idea, one of the drivers gets through brake pads four times as fast as the other drivers...

so it does seem then that vehicles used in a 'door to door' type scenario, rather than a start once, run all day scenario, are the worst 'offenders' as far as the issues with the engine are concerned

 

[Uncle Benz]

Photo bucket have turned the pictures back on! I don't belieeeeeeve it!!

 

[Glynn350]

Photo bucket have turned the pictures back on! I don't belieeeeeeve it!!

Any further thoughts on the OM651 2 years on? I found it slightly amusing that you said they were quiet! In my experience they are much louder and rougher sounding than the 642 in the same application, and other equivalent ~2.0L diesel cars (beemers etc).
I think it would be my main reason for not getting one over the 642.

 

[Uncle Benz]

Any further thoughts on the OM651 2 years on? I found it slightly amusing that you said they were quiet! In my experience they are much louder and rougher sounding than the 642 in the same application, and other equivalent ~2.0L diesel cars (beemers etc).
I think it would be my main reason for not getting one over the 642.

I've seen an awful lot of them through my shop in the interim! I think Mercedes must have improved some parts, as we don't seem to do so many water pumps of late. The later three bolt fixing coolant outlet/fuel filter holder has resolved that coolant leak issue too.
I think there is a general consensus that a lot of the chain issues were being caused by stop/start technology, and I advise people to switch that off. A large number of cars now have dead aux batteries and owners don't replace them. Stop/start doesn't work if the aux battery is dead, so that's helping too.

 

[John Laidlaw]

Interesting update and makes sense
The 651 is reasonably noisy but strangely I don’t think it’s a bad noise- not as smooth as the 6 cyl clearly but not bad

 

[Westheath]

Apparently this manifold issue is common with the commercial merc techs who look after sprinters all day long. But I suppose they clock up miles at a much faster rate!!!!!
Always good to see these threads
Cheers Uncle Benz !

Oh yes I see this on Sprinters @ 250,00-300,000 miles