"Spud Demon" > wrote in message
...
>I always check my oil at gas stations because that's the flattest place.
> Well, a few weeks ago I checked and put in a quart. Only after the engine
> started running rough did I notice that particular gas station wasn't flat
> at all but on a hill, and I had overfilled the oil.
>
> Now I've changed the oil and it's at the right level but still running
> rough. I think one of the plugs is fouled. Which one?
>
> Can I measure the resistance with an ohmmeter, or will an oil-fouled plug
> give me an open-circuit reading (same as a clean plug)?
>
> The vehicle is a '95 S-10 Blazer Vortec V-6. During the period it had too
> much oil it was parked (1) leaning-slightly-right, (2) perfectly flat,
> (3) facing uphill, and occasionally (4) facing downhill. I guess if I
> can't
> measure the resistance I'll check the cylinder at the back right corner
> first.

Well, you don't mention when you did the last tune up, but you can just
pull the plugs out and see which one is fouled. they should be a tannish
color. Any plug that looks wet or looks like it has alot of carbon
(blackish color) has the possibilty of being fouled. This means it is
running rich and assuming you haven't upgraded your engine with any
improvements, chances are you may have other problems too, but if you
haven't changed your plugs in 24,000 miles or so, I would consider changing
them. ( I do mine at 12,000). I would also change the distributor cap and
rotor inside if that hasn't been changed in a while also.
Worst case scenario is if you have to add oil between oil changes,
you may be in need of a valve and or ring job. Of course if you are going
to do the valves, you might as well do the rings while you are in there so
you won't have to go back and have it cost you much more the second time.
Check the valves for proper clearance. The next thing I would concern
myself with is tightening the valve covers if you see a leak.

Hope this helps..

Fwed