tangodown

hey guys,have a 2001 screw with 4.6 she has 115000 miles,lately after sitting for more than a hour it puffs smoke(blue usually)sometimes a liitle puff other times a big cloud!!!!!bought her 5 months ago never smoked until the last 2 weeks,after changing oil to synthetic!!!3 days ago changed back to regular oil,still smoking.today i did a vacuum test with a test gauge and she read 21hg(normal with no fluctuation).this indicated no blown head gasket or worn valve guides,how about valve seals?or possibly pcv system or other problem?need help!!!!!!!!!!!!!any ideas?

gsxrdoug

I would put my money on valve seals, $150 or so to fix the problem,

whitetrucks

I agree, when the synthetic was put in it may have washed away whatever gook that had built up on the seals and allowed them to weep when the engine was stopped.

the quantity of smoke probably changes depending on the stoping position of the motor with some allowing more seepage that others.

tangodown

thanks for the reply guys!!here is what i found....on friday i did a vaccum test on the engine,my manual says 16-22 hg is a normal engine(no blown head gasket or leaking rings,or valve guides)she registered a steady 21hg.anywho i replaced all 8 plugs,#3 plug had oil all over it,not on the resitor part but the threads and the "hole"the cop goes in....maybe oil spilled in the hole and worked its way down into the cylinder one drop at a time?this sounds crazy but since changing plugs no more smoke.hopefully this solves the problem,all other plugs looked normal,it would be odd for just 1 set of valve seals to go bad within 1 week?tanks