My S smokes a bit during startup - exhausts clear for about 20 sec then a load of grey smoke comes through for a few seconds, then clears. Doesn't smell like oil burning, just like strong exhaust fumes. Also it doesn't always happen - much more noticable when it's cold, both the car and the weather. It passed it's MOT like this but I can't remember what was on the emissions test.
The only time I see smoke out the back when I'm driving is if I've been ambling along for a while then I gun it in first.
It's been doing that for a while but I've started to notice how quickly the tail pipes get turn black, the rims getting a coating of soot. Is this normal? I'm using just over a litre per 1000 miles on average, sometimes a lot more, sometimes a lot less.

So, do I need to get something done about it and should I be worrying?

 

if you do lots of short trips you will get condensation which shows up as grey/white smoke or steam this will last untill all the water is evaporated
to see if its valve guides drive the car then take your foot of the gas and let the car coast in gear for a short while repeat this about three times without giving it too much revs then floor it, if you get big cloud of black smoke your valve guide seals and poss guides are worn and letting oil get sucked down into the combustion chamber.
it could just be the ECU sensing the cold weather and running rich during the warm up cycle, try letting the car warm up to 3 bars then cleaning the tips and going for a drive if they stay cleanish you should be ok

 

Cheers - will try that tonight.

 

Sorry to drag up an old post. Not driven the car much in the last month due to holidays and working away. However I try it though, coasting then flooring it does not produce any obvious smoke. If I clean the exhausts when the car is warm they stay fairly clean but then again they do normally take a couple of journeys to start going black. The bumper does end up with spots of black soot all over it after a couple of miles of hard driving.
I've used about half a litre of oil (half way on the dip stick to the low mark) in the last 320 miles of normal driving.
Can anyone with more mechanical knowledge than me let me know if I need to be worried or not?

Cheers.

 

Mine used to do this - it was mainly used for short but very fast journeys.

On long journeys it didn't do it so much.I reckon its normal.

FWIW, swapping the oil for Castrol Magnatec significantly reduced the amount of oil it consumed.

 

I'm due an oil change and was thinking about trying magnatec. What grade do you use?

 

Try Edge 5w30.
Thats very heavy oil use IMO.
Could be a leaky valve stem seal.
Noticably worse when booting it after a long downhill with engine braking. The oil gets sucked into to chambers more.

Also when it's been sat, the oil may seep down the stems into the chambers causing a big burn off when cold.
Burning up under harder driving may be worn bores, sticking oil control rings or similar. If its intermittently bad, I would suggest the latter.

Also worn rings will cause more pressure in the crankcase, and possibly force oil mist out of the engine breather and burnt that way.

A good quality oil would be first thing to try.

 

Change the plugs, if I remember correctly, unburnt fuel causes puffs of black smoke due to a crappy spark, new plugs will sort this.

 

Cheers for the replies. I've tried coasting in gear for a while then booting it but have never been able to see any exhaust fumes after doing this. It had new plugs less than a year ago - I checked them last week and they seem OK.
Is a leaky stem seal anything to worry about?
If I take the oil filler cap off with the engine running there is more pressure than I'd expect, also the engine always seems wet with oil vapour around the filler cap and the top of the dipstick. However the only 2 other S's I've seen were also like this.
Currently I'm not sure if I should just ignore it or quickly part-ex it before my engine blows up. It's due a service but other than an oil change I don't want to spend money on it until I get this sorted out.
I'll try a quality oil first. I have been usinbg 5-40 Fuchs Titan fully synth stuff. Was thinking magnatec on the thoery that if it clings to engine parts when cold it may stop so much dripping down a leaking stem seal.

 

Definitely change your oil and start from there.

There have been a good few case of oil burners in which the new oil has solved all the problems!

Of the 2 F20C's and a B18C-R I regularly look at, none of them use oil unless it's ready to be changed.

Once changed, they use no oil again!