C70 Diesel Engine Running Rich

I have a C70 diesel as well and experienced almost identical symptoms some time ago. Reduced power, rough running, the whole nine yards. Have you checked your spark plugs recently? That might be a simple first step before diving into the fuel injectors. It could also be related to the intake manifold.

Thanks for the response. I haven't checked the spark plugs yet, but will do so immediately. If the spark plugs appear to be in good condition, would you recommend investigating the fuel injectors next? Was the problem you experienced definitively related to the injectors?

While spark plugs might contribute, my issue ultimately stemmed from the fuel injectors. Given your symptoms and mileage, it's highly probable. I would advise having a workshop perform a diagnostic check to confirm the defective injector(s). This way you can be certain before replacing any parts.

I appreciate the advice. Following your suggestion, I took the vehicle to a trusted workshop. The diagnostic check confirmed that one of the fuel injectors was indeed defective. After replacing the injector, the problem was resolved. The total repair cost was 515€.