DIESEL ADDITIVES AND DPF CLEANERS.

[stigeye]

A quick update...

Got the car back today, it seems the temp sensor wasn't the issue as once it was plugged back in it was reading temperatures. The filter is no longer blocked and the regeneration message has gone from the dash but it still wont complete a regen cycle and there are no error codes.

The mechanic put some decent fuel in it with a DPF cleaner and we will no drive it around for now as we are on holiday from Monday and the car wont be used for a week. From reading the VX Workshop Manuals there are a couple of things that it says may not show up as errors, partially open EGR and air escaping from somewhere, but both usually result in lots of soot coming from exhaust which ours doesn't seem to be doing at the moment.

Query.. I can hear air escaping from somewhere under the car, when knelt on floor near to drivers door, near or around the front wheel arch, is this normal, do all 2.0 cdti's have this 'hissing' noise when engine is on? almost sounds like a car tyre being deflated... or could this be the air escaping issue causing the dpf issue (charge air hoses?), whatever they are.

From Vauxhall Workshop Manual...

Question 6: The DPF loading is (far) below the threshold value for the flashing glow plug lamp, but the customer comes in with the SVS light on and the DPF clogged. Why?

Answer: In this case, there is very likely a hardware fault or tuning. This fault is usually due to a leak in the air-carrying parts. Often there is a split in one of the charge air hoses or charge air cooler. Due to the leak, which the ECU or loading model does not detect, the engine will emit more smoke if the pressure difference remains below a defined threshold. The increased smoke emission can clog the DPF. Furthermore, a disproportionately high loading of the DPF can be due to a (partly) open EGR valve.

Made an error when I first posted the message above. The one directly above highlighted in green has been corrected.