I know when my DPF starts to regenerate, it's happened plenty of times basically my consumption drops to about that of a space shuttle, and the exhaust sounds like it's had holes drilled in it.
It normally happens on the motorway as that's where I do probably half of my driving, so it's no hassle. However, it happened this week while I was driving around town, and it startled me to say the least!
I stopped at the shops not long after the cycle had started, and on getting out of the car, noticed a very strong smell of burning. Fair enough, I thought, I knew the DPF was cooking. So I finished what I was doing, got back in the car, and drove off. Sure enough, as soon as the engine reached temperature again, the DPF regen started again - only with a not-so-subtle difference...
Now, bearing in mind that I clearly have a DPF fitted, and its sole purpose (by definition) is to REMOVE crud from the exhaust, I was somewhat worried to see clouds of blue/white smoke - NOT black diesel fumes - billowing out of my exhaust every time I put my foot on the throttle I did stop at one point, walk around the car, and it smelt like a bonfire around the back. No smoke at idle, but clouds and clouds of the stuff under any revs.
But hey ho, 20 minutes later, the regen finishes, the car goes back to normal and not a hint of smoke. I've never seen it before on my car - anyone got any good ideas? Basically, is it OK, and why has it happened this time?