oil smoke

["Roger Farrar" <tenpalms@xxxxxxx>]

<<<<<<<<<<<If its the valve stem seals, usually the car smokes a lot at
startup >>>>>>>>

<<<<<<<< If the smoke is worse at start up and goes away, it is probably the
valve stem seals.  >>>>>>>>


This isn't really conclusive and probably more often is a sign of worn
rings. The usual manifestation is that the engine starts up ok, but as soon
as the RPM is raised much above idle, the smoke starts rolling out, the
reason being that the cold, worn rings
are unable to seal against the oil sprayed on the cylinder walls when the
engine speed is raised. The smoke tends to subside to some degree as the
engine warms up and the rings and piston expand into the cylinder.   A
somewhat better quick check of the valve stem seals is to drive the car
until the engine is warmed up, then let it idle for a fairly long period,
say 3-4 minutes. This challenges the stem seals with high intake manifold
vacuum, but does not tax the rings so much since there is relatively little
oil being applied to the cylinder walls at idle. Now step smartly on the gas
and drive away. If you are being followed by a smokescreen worthy of James
Bond, it's a safe bet the valve stem seals are shot.  Remember that all
these external check are just indicators, and that often, the stem seals and
piston rings are BOTH worn
to some extent. Good luck.

Michael

Roger and Michael in San Diego
67 Crown Convertible  "Moby"
73 LeBaron Coupe  "La Bomba"
56 Sedan