[NMB]

Hi again all,

As with the fault tracing on a problem like oil consumption, I have been ticking off jobs to identify the actual problem - the latest job complete is the PVC valve replacement.

Althogh previously I had removed and inspected the PVC valve (when I replaced the turbo) after inspection of the PCV I just refitted the old component as I could see the membrane was not damaged and was intact. There were no perforations or tears and the membrane appeared to be in good condition so I just refitted it after a good clean. I thought that there was not need to replace.

However, after replacing the turbo and cleaning the induction system, my car still used oil and smoked badly inconsistently. (grrrrrrr).

So, following further advice on the forums here (thank you everyone), and my perpetual clouds of smoke, today I have removed and replaced the PVC valve with a brand new unit which included the plastic housing, membrane and spring as replacements to the existing unit. It took about 45 minutes to fit as the main intake pipe needs to be removed amongst a few other pipes etc. There is also a fiddley torq (25?) situated at the back of the PCV housing which is just very difficult to access (I ended up using an alan key as that let me do 1/6th turns to loosen and tighten).

I'm pleased to say that after a test drive today the new PCV appears to had a positive effect as there were no random clouds of smoke whilst accellerating, normal driving or imediatley after short idleing periods (then pulling away). Although I have only driven for 30 miles or so I am confident that the PCV valve replacement has had a huge positive impact on the engine as there is now no large puffs of smoke - the PCV replacement appears to have fixed this issue.

So here is my theory on why replacing the intact PCV valve has had an impact.

In my case the PCV valve was in tact but I was also getting incosistent oil burning and plooms of smoke usually on low boost scinarios immediately after idling. So this is my theory...

Once removed, I disassembed the PCV valve and the rubber membrane to inspect and (although intact) it had lost it's flexibility. Instead of a rubber, flexible feal it had more like a thin plastic feel. It still moved but instead of flexing across the entire surface it "popped" from one position to the other and I think that this is the reason why I was getting inconsistent smoking:

If the vacuum from the engine was enough to pull the membrane closed then the valve would work and stop oil being pulled into the intake. If the vacuum was not enough (on idle) then the valve could not be closed and vaporised oil would be pulled into the intake causing the engine to smoke.

So now the next problem.... Soot Filter Full..

Although the smoking issue has seemingly been cleared/resolved, I now need to sort our the DPF issue as I ran a forced Regen earlier this afternoon to clear the DPF and I was bamboozled as even though the regen was sucessful (and I saw the soot filter % reduced down to zero) after it completed, the soot percentage was back at 28...

So even after a static regen for 37 minutes, watching the Soot counter countdown to zero, it jumped back to 28 after i switched off and restarted the car...

On reviewing the sensor tempratures, there appears to be no "jumping" of readings so I am assuming that they are all working as they should?

So my next step is to replace the DPF pressure sensor and make sure that the twp dpf pipes connecting to the sensor are clear from gunk and they are not blocked. I will probably then buy some DPF cleander and try to clean it out whilst also getting an adfative for the fuel followed by a static regen...

Any other comments on how to sort this?