blue smoke on start up
 

Occasionally, I get a short, big puff of blue smoke on first start up. Lasts only a second, then no smoke. Engine starts quick, runs smooth, no ticks or knock. This seldom happens, but makes a guy wonder! 1998 E320 104.995 engine. Whats' up?

I think generally that means you need valve seals. However, I don't have that car. Hopefully someone else has more specific information.

yea as was said good guess valve seals

also what weight oil are you using ???? and if its syn oil light 10/30 than you may have to go back to dyno oil or add something like Lucas additive -

lots of miles and light oil and worn valve seals will do that and get bad over time - jz

I've been using 10-40 conventional oil, car has 133K miles. I change it every 3500 miles. Next time I'll add some Lucas and monitor the results. Valve seals sounds pretty involved, with big labor expense. Agree? The symptom seldom happens, guess I'll just kep an eye on it. Thanks

That's a textbook valve seal problem.