HELP! #8 cylinder - Ford Forums

cjrjam · 06-20-2004, 11:30

Need some help here fellas, here goes the story...
I have a 2000 4.6 Expedition and about a week ago the check engine light came on. The main problem here is that I live in San Diego and I'm in Florida(temporarily). So in my absence I had my wife take the expy to a local "mechanic" to get a diagnosis, what came out of it was that there was a misfire in #8 cylinder. The mechanic informed me, via phone, that it could just be a plug wire or plug and that it would be easy(until he opened the hood anyway). After his careful inspection he said he didn't feel capable of completing the task at hand and that I should take it to the dealership. SOOOOO I called Ford and asked what it would cost to get plugs put in and you can only imagine the astronomical amount they wanted. My dilema is that the truck is running rough but still driveable, it is the only vehicle my wife has access to and I get home in about two weeks.

Should I;
A. Have her take it in and pay lots-o-money (over 300)
B. Wait to get home and take a stab at it myself
C. Get another opinion of what is wrong with the expy

Has anyone had this problem and if so, is it hard to change out plugs or wires(if there are any). Sorry for the long winded story, had to vent.

'92BigBronco · 06-20-2004, 12:24

They're pretty easy to change the plugs on, but there are NO plug wires or distributor to speak of. Each spark plug has its own coil and is given the signal to fire from the computer via the crankshaft position sensor. All it takes to change the plugs is to disconnect the coils from the wiring harness, remove the bolt that holds the coil in place, remove the coil from the plug, and use a long spark plug socket to remove the plug from the top of the cylinder head.

If in doubt, label each wire as you disconnect them to ensure you get them back in the proper location. It is difficult to screw them up, but it is possible to cross them if you're not paying attention.

Given your situation, I would have her take it to another ASE certified shop instead of Ford. Any competent ASE certified shop will have all the tools, diagnostic equipment, etc. necessary to do the job right for less money than you would pay at Ford. It's a pretty simple job if in fact the plugs are to blame.

cjrjam · 06-20-2004, 20:12

Thanks that clears it up a bit for me. So since there is no wire, is there a way the individual coil could be messed up if the plug is not the culprit? Thanks again!

'92BigBronco · 06-20-2004, 21:05

Yes, absolutely. The coils do go bad and will cause the check engine light to come on and store the "misfire on #8 cylinder" code your mechanic pulled from the OBDII system. Plugs are cheaper to replace and if they haven't been changed yet, it is long overdue. If replacing the plugs doesn't fix the problem, replacing the coil would be the next logical step.

Hope you get it worked out.

Brian

cjrjam · 06-21-2004, 16:02

You da man, thanks for your help! I'm gonna go ahead and do it myself as soon as I get back. Guess I better get a Haynes manual pronto huh?
Thanks again Brian!

97 Expedition · 06-22-2004, 10:54

Autozone will also scan and clear the codes for free. I had that same problem while on the road from CO to WI and fixed it on the road. Plugs are no fun to do on the V8.