Very poor mpg at 21.5 mpg

[SonyVaio]

Air filter is the definitely the first placeI'd be looking. So easy to get it out and check what condition it is in. Air filters are not changed every service these days so may actually be a couple of years old and clogged?

[chrisdc]

Originally Posted by SonyVaio

Well with constant regens it either means that the DPF is indeed blocked or you may have a faulty sensor indicating the DPF is blocked and thus causing the regens?

Well, as it turns out the OBC logged some codes and this led to the dealership doing a "regen" on the DPF. Just what form this took i cannot say. Perhaps blowtorch? The car didn't seem to have any extra mileage on the odo when i got it back so it must have been done on site. They also picked up a problem with the turbo (i think a sensor of sorts). So its booked to go back for this and the third failed deadlock. (Three deadlocks gone, all only a few weeks apart - any one else had this?)

[v50inred]

The system might be similar to the one fitted to Vauxhall/Opel cars when they can do a forced regen using their computer which is done with the car stationary.

Normally done when the DPF is up to 75% blocked.

[SonyVaio]

Yes you can force a regen in with VIDA/DICE.

[Zeb246]

Did all the possible checks, and all seem's fine. At some stage I will have to get the DPF removed, as that could be causing the problem.

[RSVolvo]

Originally Posted by Zeb246

I'm relying on the trip computer, i'm not good with calculations lol.

If you've checked everything else it could be a faulty trip computer. It's really worth doing the calculations properly. Fill up the tank, reset the trip computer. Use as much of the tank as you can then re-fill - preferably at the same pump. make a note of the miles and the litres. Put the results on here and someone can then do the calcs for you. Also make a note of the type of driving you have done urban, motorway etc.

[chrisdc]

Originally Posted by SonyVaio

Yes you can force a regen in with VIDA/DICE.

Originally Posted by v50inred

The system might be similar to the one fitted to Vauxhall/Opel cars when they can do a forced regen using their computer which is done with the car stationary.

Normally done when the DPF is up to 75% blocked.

Yes, the service adviser did say something about them hooking it up to a computer.

I drove the car home after this procedure and haven't used it since because i have less than 2000km to go before the warranty expires. Its booked to go back for the turbo related issue on the 18th. I won't drive it until then.

Once all outstanding work has been completed i'll start using the car again and post back with my findings.

[chrisdc]

Well, the 18th has come and gone and 4 days later the dreaded "soot particle filter full" message is back again. Evidently my Volvo dealer is treating the symptom and not the cause. My money is still on the EGR valve. I'm going to challenge them to take it out and inspect it. If its full of crud i'll suggest they replace it under warranty and if its fine, i'll pay for the labour. Wonder if they'll go for it? I'm sure it would help if i went with some photos of clogged up valves - preferably from 2.0d motors with Powershift transmissions and under 100,000km. The reference to Powershift is important because these cars (V50 and presumably S40) have a different DPF - the everlasting one without the top-up tank. Anyone have such photos they'd like to share?

[SonyVaio]

Your problem is either the DPF is so blocked it is not cleaning properly or a sensor is faulty causing the message to say the DPF is blocked when it is not.

Yes your EGR is probably going to be full of crud but that is what happens to EGR's no matter what, it doesn't mean it is not operating correctly. If it is operating correctly then the dealer is going to do nothing about the EGR ata all.

It is your DPF/Sensors that neeed checking.

[chrisdc]

Originally Posted by SonyVaio

Your problem is either the DPF is so blocked it is not cleaning properly or a sensor is faulty causing the message to say the DPF is blocked when it is not.

Yes your EGR is probably going to be full of crud but that is what happens to EGR's no matter what, it doesn't mean it is not operating correctly. If it is operating correctly then the dealer is going to do nothing about the EGR ata all.

It is your DPF/Sensors that neeed checking.

SonyVaio, i hope you're right. Will go see dealer on Monday and post back on what they say. Thing is there isn't much time left for guesswork here. I have about 1400km of my warranty left. Time wise, i'm ok till July. When the 1400km are up, i get to foot the bills. My DPF is the same as the one they use on the D5, so should last the life of the car. If its blocking up excessively (symptom) then there must be a cause. I'm using low sulphur diesel and am doing my best to avoid short trips. The question that needs to be asked is why all the soot in the first place? (over and above what the DPF can handle) Now if as you suggest the sensors could be to blame - well then i understand. There is no excessive soot. But whether its sensors or filter, this needs to be sorted because with all the regens and the resulting overfueling, engine oil quality was compromised to the extent that it had to be changed after only 6000km. And then we have poor mpg, which brings us back to where we started. (thread)