White smoke

[Peter Palmer]

I'm still tinkering with our old van trying to get it back on the road whenever I have a bit of free time. I've repaired the clutch and fitted a new turbo cartridge, hovever its still quite smokey, this seems to have happened quite abruptly, I never noticed much smoke before. I did think it was oil getting into the exhaust from the leaking turbo, I thought it may have cleared by now but I'e only had it running on my driveway, not taken it out for a test drive yet. The thing is the smoke doesn't really smell oily, the smell is more like a rich diesel smell, the sort of smell you get from an old smokey van - could I have injector problems as well?

I know the additive tank is probably empty by now and I'm guessing the DPF is pretty full but I've been on diagbox and told it the additive tank has been topped up (its not) and that its had a new DPF (its not) just to get the warning off and the engine light out. What I also don't get is even though I told it the DPF is new it still says its 84% full. Is it worth running a DPF cleaner through it at this stage. If I can get rid of the smoke I will re-fill the additive tank and even maybe put a new DMF in it as its a bit noisy.

[CitroJim]

White smoke, smelling richly of diesel, indicates unburned fuel is going into the exhaust. It's not actually smoke but mostly an aerosol of finely atomised diesel.

If fuel is escaping unburned, this is normally as a result of low compression due often to leaky valves. Often too, the engine will run rather roughly as it's not running equally on all cylinders...

A leakdown test (a diesel equivalent of a compression test) would be valuable to assist in diagnosing this problem.

[Peter Palmer]

Thanks for the reply, I've been investigating further and on a test drive it came up with a P2033 code and went into limp mode. Conjnected to diagbox and it said something along the lines of temp sensor upstream of the dpf short circuit to earth. After clearing the fault under live diagnostics its showing 0 deg on the dpf temp sensor even when the van is up to temperature so I'm guessing its kaput.

However I cant seem to find where it is, the only one I can see is the one on the top of the DPF/CAT which looks like this.



But I think thats the lambda sensor, all the DPF temp sensors look something like this on ebay, so either my probe has snapped off or the sensor is somewhere else.



so could it be that if the sensor isn't reading then its overfueling the vehicle all the while causing the excessive smoke?

[Peter Palmer]

Also just to add, if the sensor is hiding away somewhere are the ones off the earlier 16V engines compatible? mine is a 2015 8V 1.6 HDI 90BHP or there abouts.

[Peter Palmer]

OK I've found the sensor, it sits right next to one of the pressure lines, I thought it was the other pressure hose to be fair. Now the hard bit is getting it out, tried with an open ended spanner but its just slipping off, I think the only thing to do is to cut the wire and slip a ring spanner over it, getting it hot first. Does that sound like a plan.

[CitroJim]

Overfuelling could cause white smoke...

Now the hard bit is getting it out, tried with an open ended spanner but its just slipping off, I think the only thing to do is to cut the wire and slip a ring spanner over it, getting it hot first. Does that sound like a plan.

Yes, heat and a deep socket will be good...

[moizeau]

Use a 6 sided socket not a 12 sided

[CitroJim]

Use a 6 sided socket not a 12 sided

Yes, definitely!

[Peter Palmer]

Just to be clear, there is only one temp sensor on the DPF isn't there. I know there are two pipes for the pressure.

[Peter Palmer]

Well that was hard work.



No chance of getting any sort of socket onto it as the metal pressure pipe bends round right in front of it so I had to do it with a spanner. I got the engine up to temp and then used a spanner after cutting the cable to slip it on, even with the DPF mad hot it was still so tight and I ended up doing the two spanner trick with the ring of one over the jaws of another, I'm amazed it didn't slip off the pressure I put it under, anyway its out now but its always fun working right next to a steaming hot turbo.

As you can see from the picture the probe bit had snapped off so that was the obvious fault, where it is now though is anyone's guess, languishing in the DPF somewhere probably, strangely the new sensor wouldn't go in as the hole was full of crud so I used a drill bit (by hand) to clean it out and now it all seems to work ok, I very nearly lost the drill bit inside the DPF as well and had to use some thin circlip pliers to coax it back out again. Smoke is a lot less as well.

[CitroJim]

Gosh, what a 'mare Peter... Main thing is, you did it with a bit of lateral thinking and all is now happy...

Well done

[moizeau]

Well done matey, these things are sent to test us