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Oil in the sparkplugs is probably from your valve cover worn out. Change the valve cover and you fix that. Your engine miss b/c you have oil in the sparkplug tube and it fowl the sparkplugs.
Couple things. First off, a leak down test it a great idea. If you haven’t already watched Eric’s video, watch it again. I’ll post it. Next, if you do find that your valve seals are bad, you don’t have to tear everything down to replace them, although that 4.6 would be an OHC, correct? So, hrmm…. You won’t have lifters or typical rocker arms. You will have cam followers of some type. The point I was trying to make is that there are nozzles that go into the spark plug hole that hook up to shop air. It fills the combustion chamber with compressed air, and allows you to remove the valve springs/retainers without pulling the heads. The air holds the valve in place, or at least you hope it does, or you’ll be pulling the head anyway. At least I know I’ve used onr on small block Chevys with OHV engines. I’ll try and poke around when I get a chance to see if they make the same thing for your car. Also, if you type ‘chiltons manual’ into the search function at the top of this page, it will lead you to a thread with access to free online Chiltons manuals.
Eric’s leakdown vid:
Doing a leak down test is great for evaluating the general condition of the engine, but I don’t see how that test would find bad valve stem seals. Usually bad seals cause 2 possible problems – you get a cloud of smoke when the car is started up after sitting overnight, or you get smoke out the tailpipe when you let off the gas and coast (so the engine pulls a high vacuum and sucks oil past the seals). If you do the leakdown test and there’s a problem with cyl #6 it’s going to be something more than just a valve seal.
Put some additives in the oil for cleaning the engine first. Then drive it hard, blow the snot out of it. You may have stuck rings from sitting.
try a compression test first. you can buy or rent this tool to test cylinder integrity. if the car sat as you say. I would look at valve guide seals.
lets confirm it first. C8-)Quoted From johnzcarz:
Doing a leak down test is great for evaluating the general condition of the engine, but I don’t see how that test would find bad valve stem seals. Usually bad seals cause 2 possible problems – you get a cloud of smoke when the car is started up after sitting overnight, or you get smoke out the tailpipe when you let off the gas and coast (so the engine pulls a high vacuum and sucks oil past the seals). If you do the leakdown test and there’s a problem with cyl #6 it’s going to be something more than just a valve seal.
Good catch man. It was late and I was loopy and kinda on autopilot mode.
I need some clarification here, when you say “oil on the spark plug” what do you mean? Is it a tan crusty color or more like greasy oil? Here is a video that I recently did that shows what a plug in a cylinder that’s burning oil looks like.
clarification: If you put oil in a spray bottle and set it on mist. sprayed the end of the spark plug, and let it hang to dry for an hour and then came back to it. That’s kinda what it looked like. There was a bit of black carbon build up that was around the the circular part that is exposed with the rest of the plug as well. But it looked like a light coating of fresh, wet, greasy, brand new oil.
Some more information: also the plugs had a bit of light build up that I was told is a result of a vacuum leak that I can’t seem to find by any method. Also, I changed my oil today, at 2500 miles and it was just short of a half a quart low. (so it is certainly consuming oil somehow.) Also, most of the time I drive like a grandpa, however when I do get on it hard, I will get some smoke behind the car (nominal, not like a diesel truck or anything). No smoke on a cold start, or when I let off the gas though.
apparently the main thing about this ignition system (waste spark ignition) is that there is platinum on the cathode and the anode of the plug. This ignition changes the polarity on the exhaust stroke so it essentially fires backwards half of the time.
At this point I know the fouling spark plugs are a symptom not the cause. And for some reason the motorcraft double platimums are incredibly hard to find in my town.
How many miles are on this car? If its alot, I would proceed with the compression test as suggested. A broken ring may be causing excessive oil being drawn into the cylinder and oil-fouling the plugs.
Also, if you are ‘reading’ the plugs and they indicate a vacuum leak, see if you can get a scan tool on the vehicle that shows live data. If the STFT an LTFT are high in the positives, this would indicate a vacuum leak that you just haven’t found yet. If it was a severe leak however, a CEL should be set.
What you describe is NOT burning oil but perhaps incomplete combustion, if it was burning oil you would see the tan ‘crust’ on the electrode as in the video that I posted for you. You might want to verify the ignition to that particular cylinder as well as fuel delivery with perhaps a power balance test but instead of disconnecting the ignition disconnect the fuel injector connector for that particular cylinder, test for spark with a spark tester similar to what I use in this video.
Spark tester
http://www.youtube.com/watch?v=FBUYs539cy4the car has 75,000 miles. (one of the reasons I bought it, but primarily because everyone else drives a mustang.) But, I think Eric might be on to something, A large part of the time it runs perfectly. It’s not really short much power, just has wimpy gears. I had wondered if it might be an ignition problem after I had posted this thread.
After I bought this car I started doing the normal stuff to it, and found the ORIGINAL spark plugs, wires, fuel filter, and transmission fluid from 1997. Could it be as simple as a bad coil pack or injector? (cleaning the injectors was on the to do list anyway.)
It is an INTERMITTENT miss. It just misses every 5-15 seconds at idle, and it really only happens after it’s warmed up. But, there is certainly not any tan crust on the plugs.
By the way, I greatly appreciate the help that I receive here. I’m sort of new to working on cars. I’ve always changed my oil, brakes, etc. But, diagnosing problems and things like that I’m fairly new at.
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