Quote:
Originally Posted by Zebster
I've never understood how an interrupted DPF regen can lead to a significant rise in sump oil level. I realise that during the regen cycle additional diesel is dispensed into each cylinder during the exhaust stroke, but surely when the engine is switched off (even if the regen cycle is still in progress) the injection of fuel will immediately cease while the engine's rotational inertia (surely a couple of rotations?) lets each cylinder pump out practically all of the unburnt fuel last injected, leaving only the tiniest trace to percolate down to the sump via the piston rings?
And why are only some examples of the VEA engine troublesome in this regard? I give absolutely no consideration to DPF regen in my driving style, yet somehow my car just does it's thing keeping the soot level low and never causing my engine oil to rise. Is the rising oil level issue really a symptom of another problem?
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It's the diesel wiping off the oil protection on the cylinders. It attacks this oil coating and then flows past the piston rings into the sump.
The diluted oil is also not providing sufficient protection in later stops. So cycle of wear is started that ruins the engine.
If you are offered a low mileage diesel car you need to walk away. Unless the low mileage is made up of long runs with no cold stop/starts in between.
And, of course, this problem is nothing to do with Volvo quality. The replacement Peugeot will go the same way if it suffers cold stops (which a Hybrid is more likely to do). Hopefully the new one is a petrol?