The Saga Continues...White Smoke

[Micky86]

wow a lot of reading there. Er any way of testing the pre cat?

[C-Owner]

Reading the EGT values with a Tech 2/Vaux-com should let you know its working.

[merikiito]

~~~~~~~~~~~~~

[Micky86]

Will have to find someone with one of these then. Just as a query though if the pre cat is where the heat happens would a faulty thermostat play any part in this process?

[jonnyaykroyd]

Not sure about a faulty stat - not sure to what extent that could affect exhaust gas temperature, however i think i read in the theory thread that there is an o2/temperature sensor on the pre-cat. if this is faulty the ecu may be aborting the regen prematurely. also i think the theory thread said the pre-cat temp reaches 200 then there is a second cat in the front of the dpf which raises the temperature further to around 550-600 degrees.

[renodci]

http://www.vectra-c.com/forum/showth...329-DPF-theory

Thanks mate - Lol; I've just read all through that thread (very interesting), only to find that the last post on it was from me......so I must have read it all before! Old age must be creeping on......

[DieselWig]

I'm trying to think what I would do if it were my car...I think I would....
Disconnect the DPF from the upstream (engine) side of the exhaust, sufficiently to allow the exhaust to blow. This would mean the DPF pressure sensor would not see a high saturation level (as the pre-DPF pressure would be low from the exhaust leak) and hence the regen would complete (or maybe not start?). If the glow plug light goes out after the regen finishes and the smoke clears, then it sounds like it must be a blocked DPF triggering the regen. If the smoke remains, even when the DPF is disconnected, then maybe there is an engine problem causing the DPF blockage (so anything causing poor combustion and hence filling the DPF with c**p), or maybe the DPF sensor is playing up.
This would at least cost you nothing but time. From your previous posts though with DPF hoses splitting, I would bet that either your DPF is seriously clogged due to the use it has had or that you have a more serious combustion problem that is clogging your DPF - I hope it's the first!

[C-Owner]

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?

Not sure why from the first post in this threads diagnosis by the OP himself the faulty DPF is still on the car ?

Either replace with a new one or carefully remove the DPF core wearing a mask and goggles refit all pipe work and have it immediately mapped off the ecu.

Sorted

[Micky86]

Running without the DPF attached to the car, it still smokes and tries to regen. So regardless of DPF condition there is another problem somewhere. When I can find £300 I will for sure map out the DPF but at the moment there is this regen issue cycle the car seems to be stuck in to deal with

[GazVXLINE170]

Running without the DPF attached to the car, it still smokes and tries to regen. So regardless of DPF condition there is another problem somewhere. When I can find £300 I will for sure map out the DPF but at the moment there is this regen issue cycle the car seems to be stuck in to deal with

The ECU will try and regen even without a DPF m8. They regen based on pressure difference across the DPF and at certain mileage/time intervals. It needs to be deleted from the ECU aswell bud as it will keep trying to regen. Don't know if the reason behind this is that it thinks there is a fault with the pressure sensors if you have removed the DPF - I'm guessing there.