Grey smoke from exhaust at 20K

[griston64]

Originally Posted by GrantA

I must admit there is something about the noise of the 5 cylinder engine when it revs between 3,000 and 4,000 revs it sounds just right and gives the impression of a far more powerful car, although at 215 bhp yours will not be a slouch!!

I was thinking of the Polestar map to take it up to 230 but tbh I don't think it needs it.......yet.

I know what you mean about the 5 pot though as I test drove the 4 cylinder 2.0tdi A6 and it was awful. The next option up was the 3.0litre V6 Quattro which I felt was too much of a jump and also unnecessary four wheel drive ( for me ) That made the 2.4 D5 the perfect choice ( and the seats are light years better than the Audi !!)

[showard8]

Smokes back after 6 weeks, I've seen it with my own eyes this time, it emitted for 10 mins in town, people were looking, white/grey smoke from exhaust, smells just hot, that's the only way I can explain it, doesn't distinctly smell of diesel or oil, just smells like hot burning, left no residue on my hand at all.

Oil level is 1/3 up on dipstick, water is full and clean.

Its had 4 tanks of shell vpower diesel since last time, doesn't seem to have made a difference.

[tt82]

Intresting. Is there anything you have done differently before the smoke that may have caused it?

Try taking a video of it next time, will be better than a description. Also what the car does, ie fast idle etc.

Could Petrol have been put in by accident? That would cause those symptoms!

[showard8]

Tried a video, by the time I got safely out the traffic and parked up it had virtually stopped, defiantly no fuel contamination, its 1/4 full with fuel and has had the same brand shell v-power diesel in since last time it smoked (as before it was supermarket fuel).

Its been 6 weeks and 1100 miles since last time.

Car behaves perfectly normally, no loss in power, no noise, nothing

[showard8]

Anyone know how or when the DPF system regenerates?, is there a way to tell if its regenerating at any given moment?

[GrantA]

Originally Posted by showard8

Anyone know how or when the DPF system regenerates?, is there a way to tell if its regenerating at any given moment?

From what I have read that is a difficult question to answer, if you put "signs of dpf regeneration" into Google you will see what I mean but there is lots of advice there. Your car may go through "passive" regeneration or "active" regeneration, you'll read about that in the results of the Google search.

I understand the only sure way to get a regeneration, if your car needs it, is to drive your car at motorway speeds for at least 20 minutes. If your daily journeys are normally at motorway speeds for 20 minutes or more then you have nothing to worry about. If your daily drive is only a couple of miles each way and the engine never reaches the correct running temp (how can you tell without a temp gauge!!!) then you will need to do the "motorway speed for at least 20 minutes" bit on a regular basis.

Your problem of grey smoke sounds like regeneration to me. As I understand it the process of regeneration is to get rid of the build up of soot in the DPF, the additional fuel being injected into the DPF raises the temperature in the DPF to over 600C and this turns the soot into ash. I have only ever seen grey ash so my theory is that what you are experiencing is regeneration on a larger scale than would happen normally. Does this indicate a fault? I don't know and I suspect only a Volvo Technician would be able to tell you.

I very much doubt if your car would run if it had petrol added to the diesel in any great quantity, you would have engine alarms showing up and it would run very badly.