om642 v6 diesel engine failure

[matt3234]

hi all i work for a independant merc specialist and we are starting to notice oil thickening almost like its turning to carbon which leads to oil blockage normally we fit secondhand low mileage engines but even these are coming in short supply so with the second failure this month we are rebuilding as exchange unit is £9500 +vat is anyone else seeing the same issues and do they know what the common cause could be or is it just a case of poor service history please help thanks. (v6 diesels,all models,year ranging form 2005-2008 so far)

 

[ringway]

Poor maintenance I would think. I seem to recall that the OM642 holds the world record for non-stop driving.

Are the vehicles from the same source/owner?

 

[Dieselman]

Are these cars fitted with particulate filters?

I suspect they are so there is additional fuel being injected, allied to the oil not being diesel specific oil and run for longer drain periods..voilla...Black death.

Any oil that meets the 229.31 or 229.51 criteria is petrol engine oil, not diesel specific.

 

[matt3234]

quick update,most of these vechiles seem to be hire cars or short distance runners none have been serviced by a mb specialist.just hope we are not missing something mechanical failing.fingers crossed hope to have the latest rebuild started today will keep updating on this one and anymore that come through the door.this one has a p/f and i believe the others had aswell.

 

[219]

I take it that cost is for a factory exchange engine ?

Have you tried Crewe Engines ? They specialise in rebuilding Mercedes engines and can often supply rebuilt engines on an exchange basis . They have a very good reputation .

Crewe Engines

 

[Dieselman]

I would be surprised if Crewe Engines have OM642 in stock and the O/p is performing a rebuild themselves so will be cheaper.


To the O/p.
If you intend to continue running these cars I would fit bypass oil filters and run shorter drain intervals until you are sure the oil is no longer thickening.

The bypass filter will probably solve the problem.

Alternatively get the DPF removed and mapped out, then you get the added bonus of being able to run proper diesel specific oil...it is different, which is why it can't be run in engines with a DPF fitted.

 

[ringway]

This thread came to mind when I spotted this OM642 engine on ebay. LINK.

Cheaper than the £9,500 mentioned by the OP and only delivery miles on this one for £3,600.

 

[Justin1600]

Normally happens to Taxi's because they sit ticking over for long periods of time.

 

[BlackC55]

Are these cars fitted with particulate filters?

I suspect they are so there is additional fuel being injected, allied to the oil not being diesel specific oil and run for longer drain periods..voilla...Black death.

Any oil that meets the 229.31 or 229.51 criteria is petrol engine oil, not diesel specific.

Not quite right there DM. 229.51 is a diesel engine oil as well as petrol. I've just checked the spec sheets on WIS. It is also ok for DPF equipped cars.