Hi guys I hope you can throw some light with some on going problems I have with my 2009 3.0 xfs, I have recently had my dpf replaced due to it apparently being full which I now wonder if it ever was, but either way I have a new one now, on the drive back from the garage that replaced it, it drove fine but I could hear a definate hissing from underneath the car, but as I was virtually home I decided to continue on my journey and worry about it the following day, but as I was driving up the final incline to my road I got restricted performance come up and the codes that indicated mass air flow correlation was wrong, thankfully my mechanic is a neighbour and he quickly diagnosed the mass air sensors needed replacing which we did the following day, but in the process we discovered the air intake manifold was cracked which he replaced over the next two days, I then took the car out for a quick drive and it drove like a dream, as good as new, so now to address the hissing from underneath the car, I drove the car to the garage that replaced dpf about 5 miles away with no problems at all, once on ramps you could clearly see the exhaust was leaking just after the cat on both pipes where the dpf had been fitted they removed the dpf and reseated it and applied plenty of exhaust sealant and it cured the hissing and everything was fine on the way home until once again while reversing into driveway I noticed orange dpf full warning on, so I then decided to to take the car for a further drive down the motorway to hopefully regen and clean dpf which after about 20 mins it cleared, but after getting off motorway back onto Aroads I noticed at 2500 revs it would hesitate and then push passed 2500 revs eventually I continued on journey home continuously seeing if it continued to hesitate at 2500 revs which it did while on journey home I way able to check my elm diagnostics software on phone and it throw up a code relating to turbo boost pressure so I just gentle drove home the rest of the way but unfortunately by the time I was reversing back into driveway I had full dpf red warning on and the codes relating to turbo had been replaced with dpf full code, please can any of you guys tell me how on earth my dpf could be full already? Or any other views you may have on my ongoing problems? Many thanks just feel like I want to cry right now.

 

Oh the wonders from DPF s*** !!!!! LEt me give you my experience with DPF: i bought a MB that was very well kept and had all the service history until it started burning oil like crazy. After checking with the ******* it says that it was still in range of the specified tolerances. Since i don't like feeding oil to an engine in excess (for me) i started reading a lot about this and came to the conclusion that it should be the carter respirator, WRONG!!!! After changing this, catchcans etc.etc we took out the DPF that was fully clogged, no regens, no warnings just clogged....... Took it out for test purposes and drove some kms with it but still using too much oil for my liking's...... So after a bit more digging and trying to solve this problem (still with no DPF) we came to the conclusion that it might be the turbo, new turbo (and an arm and a leg spend) and still using too much oil and getting worse... So the only option was repairing the engine, but since i'm too curious i wanted to know WHY since it was well kept, and in a perfect condition. After reading several forums and others with similar problems i came to the conclusion that since the DPF was clogged there was no way out for the exhaust pressures so it affected the turbo and the stem valves (that is supposed to be the culprit of using oil), i changed the turbo already but didn't sort my problem so the only option was an expensive repair that was priced about 7000€... Needless to say i ditched the car, and bought an XF but as you can see there are more problems and consequent engine damage then it's worth!!

Before you all start that i should have driven the MB on highways etc. etc. i do about 1000Km a week and do a lot of highway sometimes too fast so this shouldn't have happened. First thing i did when i got my XF was taking out the DPF, and i love the sound it makes. MOT/ Inspection is no problem, i just came from it and it didn't came up so the values are ok.

As was already stated on the WWW the DPF is a filter that was imposed to be on vehicles, the nasty stuff still gets in the atmosphere and it only makes us use more fuel to do regens. It chokes the engine and puts stress on the exhaust (back pressure) so the lifespan of an DPF fitted engine is less then without. You still see cars in some countries with 1Million Km on them and there are no DPF or other restrains on them!!!!

I hope that you can solve your problem without spending too much but if you're having (already) turbo problems maybe its time to exchange the engine or the whole car because things get expensive very very fast.

Beco