Elle wrote:
> 1993 Civic DX, 197k miles. Purchased in July 2008, with me as second
> owner. In March 2009 it started burning/losing oil at about a half-
> quart per 600 miles.
>
> -- Several times over the last couple of months I have thoroughly
> inspected the areas of the usual seals: dizzy o-ring, front crank and
> cam seals, valve cover gasket, upper and lower spark plug tube
> gaskets, oil pan gasket, rear engine seal. No leaks in these places
> that I can see.
>
> -- Replaced PCV valve a month ago. No change.
>
> -- Coolant level is steady; no signs of a head gasket breach.
>
> -- Runs superbly, otherwise. 42 mpg averaged over 24 tanks of gas
> since March. I wonder whether the oil burning has upped the MPG a bit.
>
> -- Inspected the spark plugs. They do not have black oil residue on
> them but all four are an odd, textured color of brown and not the
> usual properly combusting spark plug color.
>
> -- Replaced valve stem seals a week ago. Still consuming oil. Thought
> it might be the valve stem seals especially because driving down a
> mountain using much engine braking yielded a report from buddies that
> smoke was blowing out of my exhaust. One buddy said it seemed blu-ish.
> Others were not sure.
>
> -- Yesterday discovered the o-ring on the breather chamber had
> permatex ultra-gray or similar on it, apparently as a temporary fix.
> Also found oil residue beneath the hose connection to the breather
> chamber. I cleaned the chamber up and replaced the o-ring. I
> Hondabonded (I know, cheap) the grommet where the PCV valve hose
> connects to the breather chamber.
>
> Questions:
> 1. When an oil ring or the valve guides fails, is it usual for all of
> them to fail at about the same time, thus explaining why the spark
> plugs are all the same color? This does not pass my common sense test,
> but maybe experience is a better substitute for common sense..
>
> 2. My theory with the breather chamber is that it was running at
> atmospheric pressure or so, and this may be higher than the usual
> pressure, meaning the PCV valve was open more often and wider yada
> than it should be. Comments?

what brand of oil are you using? and what brand of gasoline?