I followed my wife to drop off our 2016/66 L405 for an MOT early today. While driving behind her having just started the car, going up a slight hill, the car was smoking very heavily. It's only done 31,000 miles and was last serviced just 3 months ago, just over 1,000 miles ago.

The car doesn't get that much use and has been stood for exactly 30 days (having just looked on the in-control app).

The only time it came out of the garage between then, was for a wash - The engine was sat running on that day for about 20 minutes, don't know if that could be a factor?

The smoke did completely vanish after a few minutes of driving, but was definitely very heavy.

Any advice or thoughts would be much appreciated

With the lack of use and getting the exhaust up to some temperature I’d be inclined to say it’s just steam, especially as it’s turning damp as the weeks go on. In a car that’s used more frequently it will burn off quicker as there will be less condensation in the exhaust to start with.

Colour of the smoke?

I wouldn’t worry about it  visiting from www.rrsport.co.uk

It was probably cold enough earlier for the F.B.H. to fire up ??
Mike. G reg 2.5VM Vogue Portofino red 1991- 1999
V reg 2.5td P38 Rioja red 1999- 2006
53 reg td6 Vogue Oslo blue 2006- 2015
11 reg 4.4 TdV8 Vogue SE. Baltic blue 2015- date.
https://www.fullfatrr.com/forum/topic56162...tty+affair

As asked earlier what colour was the smoke ? Last night I lay in bed looking up at the stars in the sky and I thought to myself, where,s the f**king ceiling!!

Thank you all for your comments - I'd say it was whiteish but with a definite hint of smoke, not just steam

My car did that a few years ago.
It was oil that was pooling in the exhaust and burning off after sitting around.
JLR did a mod to drain this oil back into the sump.
It was coming from the turbo I think.
This could be one cause.