V50 Engine 2.0D : Stuttering, High comsumption | HELP NEEDED

[Crazylachesus]

Hi,

I've bought a V50 2.0d 4 months ago (2006 model, euro 4 DPF). The car had a slight stuttering at low RMP-s and low engine load (mostly when cruising, or when accelerating delicatly). This was kind of intermittent, sometimes it went away almost completly, sometimes it could get very bad, causing massive yanking. Other symptom was that the car sometimes lost all power. There was no light on the dashboard, but even if I floored the gas, the car would just accelerate very very slowly like i was just barely touching the gas pedal. After shutting down the engine, and starting it up again, the power came back instantly. Also, after cold starting I had a very rough, jumpy idle for a minute or so. Moreover after a few tanks of diesel, i realised that the car's consumption is very high. On the 4th tank, I got around 27 MPG. I tried to read error codes with a generic odbII scanner, but there were none. After a while I got very frustrated, so I disconnected the MAF sensor. Suddenly the car felt very different. It was much stronger on low revs, NO stuttering AT ALL, and hey: the consumption went down about 2 liters /100km (38 MPG). So I drove the car like this, and ordered a new MAF sensor. Unfortunately after fitting it in, the same lumpyness and high consumption returned. After this i have disconnected the EGR and the car ran great again. However If everything is connected, all of the problems return. I even get a symptom after a cold start, the car would just not accelerate at all. And suddenly after a few seconds it wakes up and return to normal. I checked the EGR pipe that goes to the intake, and it was hot just after 2 minutes after cold start. I'm not sure, but i have heard that the egr should not redirect exhaust gases until the engine is warmed up. Could this be a faulty ECM? I have called the volvo garage that serviced the car for the previous owner, and the EGR has just been changed 6 months ago, and we even inspected it, it seems brand new. The DPF also got a cleaning and the eolys topped up ~8 months ago. Does anybody has any clue what could case these annoying smpytoms and how to fix them? I'm also going to visit a mechanic today, i'll update the thread when i get new information.

Thanks and best regards,
Balin