UK Car Repair Questions? Ask a Mechanic for Answers ASAP
Have you checked the engine oil level and the coolant level yet?
What is a dpf?
Does this dpf have anything to do with the egr and if so, why was it replaced and is the egr working?
Ok, I am not a diesel mechanic so I will have to opt out.
We need to know if the diesel fuel is in the oil again. The knocking noise could be a bad injector. If that is the case then the oil will be full of diesel fuel again. Sounds like there is a mechanical problem that needs to be addressed. As for price, it sounds expensive.