Yesterday I ran some Diesel Purge true my engine, that's when I noticed that there was "smoke" coming out of the oil dipstick tube.
Is this a problem, or can I ignore this?

Oil gauge is always at 45 when driving and at 30 when idle. Coolant temp never exceeds 185F. Oil used: Delo 400 15W-40.
Engine runs strong, sometimes a little rough in the morning for 3/4 seconds. It doesn't look like I'm loosing oil, don't have to fill up.

Thanks

It's blowby. Do a search on it and you will find lots of info and opinions. Probably nothing to worry about.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

If it's blowby there should be oil in the air filter, mine is clean ?

Not necessarily. Open the oil fill cap while the engine is running. You will probably see the smoke there also. All engines have some amount of blowby. It used to be, back in the 60's that it was just vented to the atmosphere through a tube. You could see the smoke coming out. Then PCV valves came into use making the smoke invisible.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

It's visible when I open the oil fill cap, glad I don't have a problem. Never noticed it before.

Thanks for the fast response.