Post
by Socrates101 » Mon Dec 18, 2017 6:11 am
I had same exact issue and unplugged the MAF sensor to receive linear power again, although at a little bit hotter engine and about 10% hit to fuel economy. Bottom line, it was my diesel particular filter creating back pressure. I deduced this since the bloke who owned it prior to me lived in the city and let his wife drive it often, and we know how they drive stick by never downshifting. Nonetheless, after 2 years of being lied to by BMW mechanics about needing to decoke the engine etc. which made zero sense and other stupefied mechanics, I told the one I trust who thinks out of the box to conduct a pressure check on each cylinder and to look at the aft diesel particle filter and sure enough, that was the issue. He had it cut open and burned out and fixed by another guy for about 250 Euro. The back pressure prior was 35mbar and after cleaning 8mbar. Also, 125g of carbon/clog/soot was taken out. Funny thing, I see no posts about the particulate filter being a solution. So, unless the mechanic was misleading me, who knows. But it sounds logical. Good luck!