Is it ok to run a 25% diesel 75% oil mix in a 2.0D?

[chrisdc]

Is it ok to run a 25% diesel 75% oil mix in a 2.0D engine?

I'm going to have to make a decision this week on the fate of my car. As documented elsewhere, my car has done under 4000km since it's last Volvo dealer service. At present, according to an independent analysis of my oil (sample taken by another Volvo dealer and outsourced to specialist analyst), there is a 10% presence of diesel in my oil. All things being equal, by the time I get to 8000km this figure will have reached 20% and by 10,000km (next scheduled oil change) I’ll be running a 25% diesel 75% oil mix in my sump. Will this mix be good for my engine, turbo etc.?

I am under the impression oil plays an absolutely critical role in an engine. Any old oil simply won't do. Some oils are even “co-engineered” by both the engine manufacturer and the oil manufacturer. The dealer approach to dilution of engine oil with diesel seems to be limited to draining off the excess. I'm no expert but simple common sense tell me this is a bad idea. What do you guys think?