Could this be an issue with our Diesels ?

Came across an article concerning rising oil levels in diesel engines, one of the causes is fuel dilution ( diesel fuel in the crankcase ) , this can happen in many ways from incomplete DPF regeneration cycles or leaking injectors, I know on mine my crankcase has always been at max level for the duration of the 10k interval but never has shown the overfilled warning. If you Google " rising oil levels in diesel engines " this issue is not confined to any one brand.

Originally Posted by ductman

Came across an article concerning rising oil levels in diesel engines, one of the causes is fuel dilution ( diesel fuel in the crankcase ) , this can happen in many ways from incomplete DPF regeneration cycles or leaking injectors, I know on mine my crankcase has always been at max level for the duration of the 10k interval but never has shown the overfilled warning. If you Google " rising oil levels in diesel engines " this issue is not confined to any one brand.

An oil analysis will give you a measurement of fuel dilution if you're concerned.

Its absolutely a real possibility when a manufacturer uses post injection to get un-burnt fuel down into the DPF for the regen instead of using a separate injector in front of the DPF. I know the General switched to having a separate injector, I think every other brand uses a post injection squirt though.

As mentioned, you can ask for a sample and do a UOA if you are worried about it, I would be interested in seeing a statistically relevant sample from the D drivers on here.

Jay

Originally Posted by jashearer

As mentioned, you can ask for a sample and do a UOA if you are worried about it, I would be interested in seeing a statistically relevant sample from the D drivers on here.

Jay

Here's a single analysis which shows minimal fuel dilution:

http://www.bimmerfest.com/forums/sho...d.php?t=475850

OP, thanks for this interesting topic. I know people over at TDIClub.com have been debating this for a while now.

I was reading up about the upcoming Mazda diesels and they were suffering from this issue and they needed frequent oil changes (much more than the usual BMW/VW/Audi/MB ~10k miles) to alleviate these issues.

I think this really isn't a problem with our diesels, if it was, it would have cropped up. Same with the various VW/MB/Audi diesels out there. People have tested oil dilution at factory oil intervals on the 2.0TDI VW CRD engines and they almost always said that the oil was ok to even longer than the recommended intervals.

I did have an oil level too high message, but it was linked to a broken oil sensor, not dilution.

I think it's safe to say the Germans know what they're doing when it comes to diesels.

Originally Posted by AutoUnion

OP, thanks for this interesting topic. I know people over at TDIClub.com have been debating this for a while now.

I was reading up about the upcoming Mazda diesels and they were suffering from this issue and they needed frequent oil changes (much more than the usual BMW/VW/Audi/MB ~10k miles) to alleviate these issues.

I think this really isn't a problem with our diesels, if it was, it would have cropped up. Same with the various VW/MB/Audi diesels out there. People have tested oil dilution at factory oil intervals on the 2.0TDI VW CRD engines and they almost always said that the oil was ok to even longer than the recommended intervals.

I did have an oil level too high message, but it was linked to a broken oil sensor, not dilution.

I think it's safe to say the Germans know what they're doing when it comes to diesels.

I actually as you read about this on the upcoming Mazda diesels also, apparently in the owners manuals of the Mazda's , it states that the when the oil level rises to the " X " on the dipstick , the oil needs to be changed or risk engine damage, some people have had to have their oil changed within a couple of thousand miles !