The Saga Continues...White Smoke

[Micky86]

So following new turbo, blanked EGR, new Vacuum pipes, it turned out the cause to my problems was a blocked DPF! This was originally ruled out due to the long daily commutes.

So, DPF of it ran well. Jet washed out, left to dry, re-fitted this morning.

From cold the car runs fine. Once warmed up though a white/light greyish smoke comes from the exhaust on acceleration and then lightly even at idle. When this happen MPG goes right down. There is a smell to it as my friend would describe, like the smell you get when lighting a bbq. Like burning paraffin.

Suggestions?

[homerj]

its only a guess but sounds like unburnt diesel which i would say was an injector problem. if it was from cold you could say glow plug but this way i would say injector.

[Micky86]

I was thinking similar. Where do I start with injectors???

[Micky86]

Still have the smoking problem. After 5-10 mins of driving it starts. If I turn the car off and then back on again it goes back to normal for 5-10 minutes before smoking again. This in my mind sys it could be an ECu thing perhaps telling the car to put more fuel in? I really don't know, could it be a timing issue? Also does anyone have a link to or a detailed description of how the DPF pressure sensor works on the 150?

[merikiito]

Are the rubber hoses that go to the DPF all in place?

[Micky86]

Yes, I have replaced the rubber hose for the pressure sensor as that one had blew. replaced it with some slightly smaller diameter hose, would this make a difference?

[merikiito]

Yes, I have replaced the rubber hose for the pressure sensor as that one had blew. replaced it with some slightly smaller diameter hose, would this make a difference?

Who knows, but its a starting point

[Micky86]

Disconnected dpf pressure sensor, fuel consumption went up, but still smoking after 5 mins. there is also an engine judder at 1000 revs. I'm starting to think this is an injection/timing issue. Anyone got any experiences in this area?

[DieselWig]

Sounds like the ECU is trying to perform a DPF regen to me because:-
1. Burning smell - regen makes the injectors fuel more to heat the exhaust to burn off soot.
2. Fuel consumption up - as above, regen asks for more fuel to be delivered.
3. Disconnecting pressure sensor affects consumption - the differential pressure sensor is there to measure the exhaust gas restriction, so messing with this would affect what the ECU thinks the restriction is across the DPF.
4. DPF hose blew - suggests back-pressure on DPF, but probably a result of a blocked DPF.

Anyway, all sounds DPF related to me, one way or another. The DPF not only becomes blocked with soot (particularly on short journeys) but eventually a build up of ash from the regens means that cleaning the soot off will no longer help.
If you can get someone with access to a diagnostic tool (Tech2/OPCOM) then you could check your DPF saturation levels.
Otherwise I would suggest (before spending anything on injectors at least) considering removing the insides of the DPF (carefully, with a big hammer/long bar/drill & of course mask), and getting a remap. It will likely cost £200-300, but may save you that in fuel costs over time.

[Micky86]

Thanks DieselWig, I had the DPF as it was very blocked and ruined my turbo. I cleaned it out and the can ran fine again, but now it is as if it's overfueling like a regen, but religiously around 5 minutes after starting. Can turn it off wait a minute turn it back on 5 minutes later it starts again. Can the ECu get stuck in a cycle thinking it needs to regen?