Which cylinder is oil-fouled?

too much oil in the crankcase is a no- no. (you are cautioned - to not overfill)

after you change your oil the next time and know the right amount is in your

crankcase, and the filter has loaded up - regardless of the place it is parked, if it is

parked there over night each time, take a reading, and you'll know where the full mark is, (lightly notch it with a file)

and be governed accordingly when - adding oil.

There might be a gasoline additive that will help clean the plugs if it is given enough hiway driving after use.

mho v=83e

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

How do you know it's one? How do you know it's not more than one?

Oil is pretty nonconductive. That's why they fill transformer vaults with it.

Come on. How long can it take to pull all the plugs and check them? Five minutes? Six minutes, maybe?

--scott

Usually, if a plug is mildly oil-fouled, you don't even have to remove it. Merely pull one plug wire at a time, either end, & when you find one skipping both before AND after removal, hold it just close enough to its proper location for it to 'fire thru the air' or 'jump the air gap'. Often the fouled plug will fire the cylinder when it jumps such a gap--less than 5 minutes, start to finish for all plugs. For the one(s) that fail to fire using this procedure, remove it/them & clean/replace accordingly. Better, if you find more than 1, replace the entire set. HTH, s

That's a good way to burn up a modern ignition or get yourself dangerously zapped. Works fine for older cars.

Charles, you are absolutely right, and I stand correcting myself. I had just finished reading about an older v-8,250 hp, carb'd engine used to launch gliders into the air & had not moved my thinking back into the light ages. Thanks for the correction!!! s

Because it sounds like this:

+++++-+++++-+++++-+++++-+++++-+++++-+++++-+++++-+++++-+++++-+++++-+++++-

As opposed to:

+++-+-+++-+-+++-+-+++-+-+++-+-+++-+-+++-+-+++-+-+++-+-+++-+-+++-+-+++-+- ++-++-++-++-++-++-++-++-++-++-++-++-++-++-++-++-++-++-++-++-++-++-++-++- +--++-+--++-+--++-+--++-+--++-+--++-+--++-+--++-+--++-+--++-+--++-+--++- +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+-- +-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+---+-+--- +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

I suppose it could possibly be this:

++++--++++--++++--++++--++++--++++--++++--++++--++++--++++--++++--++++--

but I'm betting on the first one.

I replaced all the plugs and wires 10K miles ago. 3 hours and a couple of rusty-metal cuts when I broke the plug loose. I would love to cut both numbers down by a factor of 6.

If only I had a Nagra!

-- spud_demon -at- thundermaker.net The above may not (yet) represent the opinions of my employer.

"fweddybear" writes in article dated Mon, 17 Apr 2006 20:47:51 -0400:

No, it's not actually consuming oil I just thought it was 1 QT low 4K miles after the previous oil change due to an erroneous dipstick reading.

I did change the plugs recently, was hoping to avoid pulling all of them.

Thanks for the suggestions everybody.

-- spud_demon -at- thundermaker.net The above may not (yet) represent the opinions of my employer.

Your oil overfilling scenario is a pure pipe dream. An extra quart of oil is not going to cause oil fouling. Also, it makes no difference whether you park the car on an incline. How about the poor folks in San Fancisco or the Smoky Mountians? The fact that your engine started running rough after you added a quart of oil is merely coincidence. You have another problem; just look for that cause.

Just pull the plugs and replace any that look suspicious. It will take less time to yank the plugs than to draw graphics and post messages.

"Al Bundy" writes in article dated 18 Apr 2006

05:42:33 -0700:

This morning I started by pulling spark wires off the distributor cap, one at a time, then starting the engine and listening. I found the right-rear spark plug wire had no effect (+++++-), and the 2 with the worst effect (++++--) were the ones on either side of it, like sdlomi2 said.

So I pulled the right rear spark plug. It was much easier than last time, having been in there only 10K miles.

It had some black carbon on it and the (aluminum?) part that sticks out in the center was worn way back. So I replaced it. Now the engine runs smooth and strong (++++++).

Al, I'm not saying parking on a hill is bad. But if you overfill your oil and park on a hill, the first cylinder to foul will be the one which is lowest. I'm pretty sure that's what happened in this case. I guess you think the problem will recur, since it wasn't caused by excess oil?

-- spud_demon -at- thundermaker.net The above may not (yet) represent the opinions of my employer.

"Chas Hurst" writes in article dated Mon, 17 Apr 2006 22:28:40

-0400:

I didn't do the "jump the air gap" trick but I did start the engine with various wires disconnected from the distributor. There were occasional sparks from the uncovered terminals to nearby ground, an inch or more away. I wouldn't want to handle those wires when they're live!

Reminds me of when my friend's lawn mower was running rough. I said "that spark plug wire looks loose" and put my hand on it to secure it. OW! OW! OW! OW! OW! OW! OW! OW! OW!

-- spud_demon -at- thundermaker.net The above may not (yet) represent the opinions of my employer.

On this particular vehicle? Hah. I took me almost an hour to get to #3 on a '96 Blazer with the same engine. It is crammed way down in there, right behind the steering box/column. The heat shield doesn't help either.

I think it was 4 hour job to get the middle two plugs done and about

20 minutes to do the other 4.

FWIW: If it is missing, the computer should be able to tell you on which ones. With a code scanner it should be able to tell if any plugs are not firing consistently.

As for oil fouling by overfilling. I dont' buy that. You would have to be on a very steep incline to get to the point where oil was draining back to any particular cylinder. Very steep. You have other issues. It was almost purely coincidental that it happened the same time as you last added some oil.

JW

Bullshit. Where in the world do you get the idea that an extra quart of oil will cause a plug to foul? It won't, whether you park on a hill or not. Your problem had nothing to do with the oil.

That's a good way to burn your cap (carbon tracks).

Then you WILL have a miss! :-)

Could be valve stem seals.

The rears get more oil, because the engine slants that way, usually.

That's why large V-8's usually foul the rear plugs first, when the valve guides/seals start to go.

So what do you think happens if you put too much oil in an engine?

I'm sure my vehicle will have more problems someday. Then all you nay-sayers (or 1 guy with a few sock puppets?) will be right!

-- spud_demon -at- thundermaker.net The above may not (yet) represent the opinions of my employer.

In a pressure oiled system(nearly every car built), not much. The crank will probably start "whipping" the oil and you will have extra drag, but nothing really "bad' will happen.

In a splash oiled system(ie your lawnmower), overfilling is VERY bad. The same thing will happen(somewhat by design), but it will not be able to splash properly and you will starve the engine for oil. It's a little counterintuitive.

Now if you put WAY too much oil in, then you could probably cause problems, but you would have to be several quarts extra. Then you will probably start pumping oil out the PCV system and gum that up.

FWIW- it sounds like your plug(s) was just worn out. You were due for a plug change(and maybe wires). Might not hurt to change the rest of them. Usually done in sets, so if one is that bad, the others are probably not much better.

JW