O2 sensor and white smoke

[John Hess]

Additionally, there are "Shades" of blue.  I have seen copious clouds 
of white (appearing) smoke that were oil.  I have seen white smoke 
that meant a burnt head gasket.  The conditions you describe, white 
(pale blue) smoke under heavy acceleration may or not be a real 
problem.  How often do you have to add oil?  What do the plugs look 
like?  You are probably showing cylinder/ring wear.  Please be aware; 
 however, that the catalytic converter can "clean up" a lot of smoke 
on a car that is burning a LOT of oil.  In this case, it will smoke 
until the cat lights off and during heavy acceleration.



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From:  FJB203 at aol.com[SMTP:FJB203 at aol.com]
Sent:  Monday, February 03, 1997 1:02 PM
To:  diy_efi at coulomb.eng.ohio-state.edu
Subject:  Re: O2 sensor and white smoke

In a message dated 97-02-03 11:27:50 EST, you write:

> Is the O2 sensor supposed to replaced as part of regular maintenance 
and if
>  so, how often?

Well, that depends.  Most passenger manufacturers say they will last 
100k.
 Of course, if you have a turbo or the engine runs really hot all the 
time,
they cook sooner.  I generally have replaced them as a last resort 
when the
car doesn't run that well, and I've replaced plugs, filters, plug 
wires, etc.

>  Also, let's talk about causes for white smoke. Not thick and 
bellowing but
>  visible from behind during heavy acceleration from by high mileage 
302HO.
I
>  was told by a friend that it is frequently caused by valve seals. 
I
thought
>  that leaking valve seals was mostly evident during starting by blue 
smoke!

Blue smoke means you have oil in your combustion chambers, typically 
caused
by poor piston ring seating (either installed incorrectly, or more 
common -
worn out).  White smoke definately can come from the valves not 
opening and
closing all the way or at the right time, however you might want to 
check
ignition coil spark voltage.  Sometimes a hotter spark can clean that 
up.

Fred