New owner of 525 TDS
Hi everyone! After owning old Porsche and Audis, I bought E39 525 TDS while living abroad for commuting purposes. I advice of those who know M51 engine:
- I stupidly put "disel injector cleaner" into the fuel tank. Afterwards car started stalling when I shift from 1st to 2nd in traffic. INPA shows regulation error of high-pressure injection pump. Does it mean it needs cleaning or may I survive with fuel filter replacement (never replaced in last 30 000 km, I think)?
- Car goes quickly and pulls strongly. On 4th gear WOT, display shows 20+ L/100 km fuel consumption. But, I see clouds of black smoke when I accelerate hard. And I see hose clamps near turbo are covered in oil. Turbo needs replacement or it's typical M51 crankcase ventilation issue?
- Do I need to replace something in the cylinder head cover when I will be cleaning the filter integrated inside?
Posted May 12, 2026, 8:17 AM UTC