Help with a diagnosis...

[spiking68]

1998 Ford Explorer 6C OHV; My truck started running very rough during acceleartion and the engine was sputtering at times while at constant speeds. The Check-Engine light came on so I took it to a Shell Service Station. They told me that the #4 cylinder was misfiring and said a general tune-up should fix the problem. I figured all I had to do was replace the wires (and I had just replaced the plugs, oil, filters just five months ago...) but I told them to go ahead and do the tune-up (Cuz I didn't want them screwing with anything else under the hood...) Anyways, I saw that they replaced the wires and the truck ran great. 2 weeks later the check engine light came on again and I was having the same exact problem. I pulled, what I will call the #1 plug (numbering from the driver to the passenger in a "u" shape around the engine 1,2,3,4,5,6) and it was fairly gunked up with oil residue. (and it was the exact same plug I had put in there five months ago.. also the gas, oil, and air filters were the ones I put in. So I got charged 300.00 for a tune up that consisted of new plug wires! Bandits!) I replaced it with a new plug and truck ran great for about a week. Then I started having the same engine problems as before. I just went out and changed all the plugs and when I did I noticed that the #2 plug was gunked up like the #1 plug (these are the ones closest to the oil dipstick). Well the truck runs fine now but I would imagine I have a small oil leak (I say small cuz I haven't had to put in any oil since i changed it 5 months ago and the level is fine) that's gunking up those two plugs and causing the engine to misfire. Any ideas on where the oil is coming from or if I may be experiencing some other problem entirely?? Cuz, I'm not taking it back to the garage!! I fell the only reason my Bronco made it to 150,000 miles was because mine were the only hands to touch it! I was just hoping I could trust these guys... Ooops.

 

[aldive]

I would run a compression test next.

Good luck......

 

[A Wise Guy]

And always ask for a box with all of your old parts.

 

[P Wilson]

diagnosis

I am having almost the same exact problem- $312.00 ago I got a complete tune up-new wires plugs fuel filter etc...on my 91 xlt -exactly 60 days later the engine started missing terriblyagain. A friend of mine pulled the plugs and one of them was oil saturated and cracked - I took it to the shop today to have a compression test . Results in the morning. Good luck... I hope I dont have to replace the engine. It only has 80,000 miles on it and ran excellent up to this point. Let me know what you find out about yours. Thanks