Hi! I have a Mercedes Vito 115 4x4 auto 2008, recently changed the engine after the old one went dead. The new one(bought it used) has gone appr. 110 000km, I have also overhalued the gearbox.

My problem now is that the engine light comes up all the time. Went to Mercedes and they say that particle filter is blocked. They clean it and I drive for some hours and the problem is back. They have checked the engine, it is ok.
With the light coming on, the the car loses power while driving upward a hill, the gearbox also struggles, because the converter doesn't un-couple. While checking the oil, I can smell diesel in it. The mercedes people are unable to find out what is blocking the particle filter all the time. They have checked the nozzels, but they can't find anything wrong with engine. Please help me, this car has nearly bankrupted me