XSeries-forum

Ok so when I'm driving around at normal speed limit I don't notice any smoke but as soon as I hit the duel carriageway and put my foot down for about 5-10 seconds a big cloud of white smoke comes out, it's goes barley noticeable after that but I'm getting it every day when I put my foot down. Any ideas?

Can't remember what version you have.  White smoke could be steam if on a cold morning, unburnt oil, or far too much fuel, or coolant in the exhaust.  Engine temp OK?  Fuel consumption as expected?  Any smell to the 'smoke' getting into the car? 

Check coolant level, look on the oil cap for any signs of 'mayonnaise' (oil water mix that settles on the oil cap and indicates coolant in the oil).  How is the oil consumption?

Any odd noises, warning lights, performance issues?

If warm it sounds like oil smoke which could be valve stem seals, rings, over pressure - have you changed the oil separator/breather for the crankcase?  If it is blocked then you could be getting over pressure in the crankcase which will drive oil past the turbo seals.  It could also indicate a turbo problem.

It's e53 3l diesel 2002, no warning lights. The engine temp is fine. I'll have a look at the oil tomorrow. Performance wise I had it remapped for economy last month. Sometimes the turbo does lag takes a couple of seconds to kick in but it's not all the time. Havnt smelt anything yet and there's no weird noises or anything just as soon as I put my foot down a big cloud of white smoke comes out for a few seconds and then becomes barley noticeable. I did get the fuel system inject warning about a month ago but it went away the next day and hasn't come up since.

Yours will likely have the old style breather, unless someone has changed it in the past, so I suspect that's the problem. Up-date it to the vortex breather, it's only £45 and an hours labour, and I suspect your problem will go away.

Usual symptoms are brownie grey smoke as opposed to white but the rest would point to breather.

Ok bud thanks for that I'll get the vortex breather and see if it makes a difference

I've just noticed I have a coolant leak, when I look underneath the car I can see it dripping off the front of the big plate. Any ideas where it's coming from and how to find it? And could this cause the white smoke?

Expansion bottle could be cracked.  It's a known issue.  Check all the hoses etc for any sign of wetness.