Hey guys.
My 08 XF 2.7D is having problems. It's always had a few small issues but they've always been things I can deal with until now and I'm hoping they're in some way related. I'll just list the problems I can remember and see from there.
Last year I started getting the DPF full warning. After reading up on it I changed my route to work and the problem went away.
The car has always used coolant. I generally have to top it up every 3 to 4 months but there's no signs of leaks underneath.
I had one incidence of uncontrolled dieselling about 6 months ago. The car just took off when I was accelerating gently away from a turning. It lasted about 2 seconds and hasn't happened again since.
I often get a smell of burning oil or fuel in the car when I'm not moving and it sometimes smells of burning when I park up and get out.

Last night the DPF warning came on again. I decided to give it some throttle to try and clear it but, instead, the car struggled in the high rev ranges and went into limp home mode.
This morning, when I started the car, it put a considerable amount of white smoke out of the exhaust. It cleared after a few seconds but for the whole journey it billowed white smoke every time I accelerated and the DPF warning is still there.

That's about all I can think of. I'm not sure if any or all of the above symptoms are related. I can't see how the DPF can cause so much smoke but I don't know that much about the system. I know it could be caused by coolant in the cylinders but why do this now when it's always used fluid?

Anyway, any help would be appreciated guys. The hardest part of this whole thing is not knowing what to tell a garage to change. I can't afford to have them start changing bits at random.

 

Does the white exhaust smell like coolant? This would indicate a cracked head or block, but more likely, a bad head gasket. You might have cloudy oil also.

If you don't suspect coolant, then it could be a fueling problem such as a clogged fuel filter or bad injector. In a diesel car, white smoke can indicate un-burnt fuel. This might contribute to DPF clogging, and you might also notice a fuel smell.

 

You are not in the right forum for your car as this one covers XFs from 2015, but yours is a 2008. Better to post in the right forum, you should get more answers.

 

Sorry, didn't see another XF forum. Could some friendly mod move this to the right place please?

I wouldn't say I don't suspect it's coolant burning. It just seems weird that it's didn't got so bad so quickly.
I'll get the Mrs to rev it later and I'll have a sniff of what's coming out.

 

I went down and started it earlier. Didn't get smoke on startup but it did start coming out when I revved it fairly hard. It just smells of exhaust to me.
It certainly didn't smell of unburnt fuel and after holding my hand in the smoke for a while it didn't pick up any residue or wetness.

 

New symptom.
It's quite subtle but the gears don't change correctly. When I'm driving normally they change at slightly different times to how they used to. It's only something the driver would notice.
It also doesn't want to go into 6th at 60mph. It stays in 5th and I have to back the throttle right off to get it to change up. It will stay in 6th after that though.