Exhaust smoke

[pberrey]

My 179k 4.2td smokes a bit when it's hot. It's blue smoke at tick over and when lifting off although it is an auto so it's not really overrun if you follow my drift. It doesn't normally use any oil but I've just done 300 miles since my last check so I can double check it tonight. Power and all other engine characteristics are normal.

Any thoughts on the likely causes?

 

[karl webster]

Valve guide stem seals maybe.

 

[joinerman]

If it was the stem seals Karl would it not smoke more on first start after being stood for a while, in my opinion for what it's worth probably sticky / stuck ring / rings, BUT then I'm probably wrong.

 

[karl webster]

Thought stuck rings gave blue smoke all the time.

When engines cold I expect oil to be thicker so harderto pass the seals When oils hot it gets thinner??

Just my thoughts.

 

[Towpack]

Possibly turbo seals. Check for oil in the inlet tract downstream of the turbo, not forgetting that some could be from the PCV hose. Clean out the hoses either side of the turbo, run the PCV hose into a catch can or something similar and then run it like this for a while. If the air hose downstream of the turbo oils up again there's your answer.