hi deepbluex and every one else.
there sure have been lots of great info here and on the other treads on this forum.
when you have a really good running car that smokes, this can really be a problem.besides maybe getting a ticket who wants to be seen with blue smoke behind them.diesels are differant,but there is some thing about blue smoke.
anyway this is more about not opening up a good running engine that has a lot of miles left or is not cost effective.
syntetic oil is a good first step before doing that valve job.
i would not flush the engine first. syntec oil (15-50 mobil 1?)
has enough cleaner in it to slowly clean out your motor, maybe leave it in1-2 thousand miles the first time. the seal conditioners will do there thing on the valve guide seals.
may even free up the rings a little with the cleaners.
at first the smoke will lessen and within a thousand miles there will be a major improvment if it is going to work.using a high milage oil does not work on a car that wants to smoke blue.
the syntec oil , if it smokes,it will look like clear heat waves. the kind you see off of some thing really hot.
i tried a no name sytec oil from kragans. still had some color, like blowing out carbon with an italian tune up.
my next try with mobil one 15-50 did the trick.what i did not expect was the oil usage to be almost zero from what was 1 quart per 400 miles.after about 3 thousand miles ,zero smoke.
the old timer was right.
this is a good way to start, then you can decide to go futher if their is still a problem. this is a good thing to use if your car only suffers from old age. rich

__________________
88 300E White, sold 9-04
88 190E Black 2.3 sold
90 300CE White, Grey sold 12-24-04
92 400E White,Grey Sold 5-06
90 300CE 91K Signal Red,Black Sold 2007
1989 300CE Smoke silver,Tan Sold 1-08
1993 300E 3.2 M104 motor
1991 300CE White,Grey
1994 E420 beautiful car,gone to new home
1994 E320 Smoke an Parchment.Beautiful car