I have a diesel that's in at the mechanic at the moment because it's blowing plumes of blueish smoke every now and again. 4 different mechanics have all had dif

I have a diesel that's in at the mechanic at the moment because it's blowing plumes of blueish smoke every now and again. 4 different mechanics have all had different theories (ECG valve, turbo, air supply system, injectors) so as a result I've had to learn a lot about it myself because I no longer trust any of them. Currently I'm starting to think the issue is with the DPF (diesel particulate filter) system which is responsible for pulling the soot out of the exhaust. The extra soot is the result of reburning the exhaust in a 2nd combustion to try to keep the emissions down. There's then another process (DPF regeneration) that pumps extra diesel into the engine during the exhaust stroke to try to burn the carbon particles out of the DPF to keep it clean. Stopping to think about the horrors of the filthy process that goes on inside all of these vehicles is eye opening, to say the least. I know electric vehicles aren't without an environmental cost — but if there's anything that can be done to move the pollution away from urban environments that seems like a pretty positive thing to me. I suspect in 50 years time people are going to look back on the burning of fossil fuels with shock.