4.6L v8 Misfiring on 2000 Expedition

Greetings Folks, This is Erik (I'm normally posting on here regarding a 95 Explorer out in Arizona)

Anyways, I have a family members truck that's having some issues. Its a 00 Expedition, 4.6L with 49,300 miles on it. Regular maintenance performed. No major problems what so ever till today.

All of the sudden, during acceleration today the car hesitated, had this sudden vibration. The Service Engine Light came on. I drove it to AutoZone to pull the code. The code read a miss-fire in Cylinder # 8. (not sure of the exact code #, but that's what the handy reference book translated the code into) They suggested I have the plugs replaced. Sounds cool.

However, I'm not sure if this is mere coincidence, or it had something to do with it. I took the Expedition to the local quick-lube place today to have the oil changed. All seemed to go fine. Drove home (less than a mile from the oil change place) Then drove a few hours laters to the local shopping center. (About 5 miles away on the highway) So after 6 or so miles after the oil-change, the problem started.

My question is- is this a common problem on the Ford 4.6L V8 (regarding spark plugs needing replacement) Or could there have been something done accidentally during the oil change that might have loosened a plug or something else to the point that Cylinder #8 is misfiring. (At least what the code is reading out)

Thanks everyone in advanced for any ideas, suggestions, solutions.

Hope everyone is doing great out there.

Erik reply to this board or erik*NOSPAM*trevino@earthlink

Reply to
Erik in SAT
Loading thread data ...

My brother had a similar problem, turned out to be the COP (coil on plug).

The dealer said they routinely have to replace them, to the tune of a little over $200 each.

Reply to
Tommy Wood

Ouch. That's when the extended warranty gives you a warm feeling all over.

Reply to
AZGuy

Extended Warranty???

My brother has one.

But, the dealer tells him he has to pay for the COP.

It's not covered by the warranty. My brother was a little steamed. Probably the last extended warranty he ever buys.

Reply to
Tommy Wood

Almost every one I looked at offered a no-deductible option. It's true that different ones offer different coverage and you have to read very carefully what's covered and what isn't. Generally speaking, the more you pay, the better the coverage. I'd like to see the policy that excludes the COP. I can see them excluding wear/maintenance items but the coil hardly seems like a wear/maint item to me.

Reply to
AZGuy

This is unfortunately a fairly common occurrence on older Expeditions (more so for the 5.4L). It is most likely a failed #8 coil pack. This particular coil pack is located at the rear of the engine on the passenger side underneath a quick connect heater hose joint that has a bad habit of leaking (particularly if it has been disconnected for some reason). If it leaks even small amounts of hot antifreeze, it can take out the #8 coil pack. Even if the hose connection doesn't leak, the air flow in this area is very restricted and the coils run hot. I paid around $300 to have the #8 coil pack replaced on my old Expedition at around a 110,000 miles - about six months after I had paid the dealer to replace the plugs. I believe the technician that replaced the plugs did not reconnect the heater hose properly. At the time the coil pack failed, I had been looking for a slow anti-freeze leak. After the coil pack was replaced, my leak was gone.

You should ask your question to the Expedition Mailing List - see

formatting link
. Regards,

Ed White

Erik >

Reply to
C. E. White

Most of the time when a plug blows out it is after someone has replaced them. If you install them too tightly, you pull the threads out of the head. If you install them too loosely, the plugs work loose and pull the last thread or two when they blow out. If you cross thread them, you wreck the threads. On a modular truck engine, the plugs are way down in a hole and difficult to reach. You might want to look at

formatting link

The #8 coil back is very hard to see. Do you know if the truck is loosing any antifreeze? If you have a high pressure leak, it is common to see a white powerdy coating on components near the leak.

Regards,

Ed White

VTREV wrote:

Reply to
C. E. White

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.