I have been scanning the message boards for the last few nights, and I am finding out that I am not alone!. I have a '97 with the 4.6l that I bought used with about 90k miles when I bought it. at about 100 k started running very rough, took it to a Chain-repair shop, and after about $400 it ran good. Then about 10k miles later, same thing starts again!. This time I took it to a local guy, who charged me $10 to change 1 plug, ran great!! Then about 5k miles later, same problems again. A buddy I work with who used to own his own shop, changed all the plugs and wire for just the cost of parts, Beautiful. now here it is again 10k miles later, and same old crap. Paid a Firestone dealer $80 for computer diag., said a misfire on #4 (again!)



2 questions: 1) can anyone tell me what the number sequence for the cylinders is, which one is #4? and 2) sholud I have plugs and wires changed again? I can do basic stuff, but don't want to get ripped off taking it somewhere again!

 

rear pass. side...check for coolant leak from heater hose dripping down on head from back there

 

I just put new plugs and plug wires on my '99 4.6. My truck had started running really rough when I had my foot on the gas, but idled fine. After I got done last night I took it for a spin. It seems to be running alot better than it has run in a while. It jumped up to 90 pretty quick without a stumble. I replaced the stock plug wires with Accel Super Stock ($99.00) and replaced all the spark plugs with stock plugs for around $10.00 a plug (seems a little high). The plugs weren't to bad to replace, but the wire clips on the stock wires were a b#%ch to open. Good luck.

 

I had some of the same problems you speak of this fall and after new plugs and wires ran fine for about a month then set code 304 again for #4 missfire. After lots of questions and few answers I decided to replace the driver side coil pack since that one services the number 4 plug. After doing that and about 6k miles it has run just fine once again. Check the primary and secondary resistance on the packs using a digital ohm meter the specs are in any Hayes or Chiltons man. Good luck!

 

Check out my post here...https://www.f150online.com/forums/sh...threadid=85603

The first mechanic noticed one of the heater hoses leaking down onto the back passenger plug and fixed it.

That was 6,000 miles ago and it still runs like new.

Here is a summary of what was done:
1. Check all fuses and o2 sensor (NC labor)
2. Replace plugs (8 @ $4, 1 hour labor)
3. Replace plug wires (Beldin lifetime warranty $112.98, 1.3 hours labor)
4. Replace TPS and CTS (high voltage) (TPS $59.95, CTS $28.10) (1 hour labor)
5. Scanner & trouble shoot (NC labor)
6. Compression check (0.4 hour labor)
7. Clean injectors ($12 machine, .4 labor)
8. Tighten and clean all injector harnesses (NC labor)
9. Check EGR valve, throttle body, gaskets and vacuum system (NC labor)

Total for parts, labor and tax = $520.64

 

I JUST bought a '97 4.6 XLT with 87,600 miles. On the test drive (before I bought it) it was skipping badly...I thought it was missing on at least one cylinder, felt like two though. The owner took it to a local shop who changed ONE wire, #4 (a new black Ford wire). The other wires on the truck are NOT FOMOCO wires (they are grey Standard brand), so this has been done before.

I don't seen any leaking, but something is causing it for sure. I'll keep my eye on it and if it starts to miss again, I think I'll just replace the #4 wire and be done with it!

 

Funny timming -- I ran into this same problem just a few weeks ago. I had a 120K service on my 97 4.6 f150 and then about a eek later this hesitation started. Took it to the dealer and they said #4 was misfiring. They replaced the plug and mentioned that the wired need replacing. After their quote on replacing the wire, I decided to replace them myself ( but I di not replcae them immediately. Two days later, #4 misfired again. The shop told me there was water in the spark plug well and it was probably from rain off the cowling. Couldn't figure out why all of a sudden rain water was getting in there after 120k miles and 6 years. They never suspected a heater leak.

I replaced the wires and they replaced theplug after much agruing. I also got them to put electrolytic grease in the plug boot to block out any more "water". (they wanted $8.00 for the grease and charge me a half hour for labor). ARE YOU KIDDING???? A tube of the grease is less than $1.00. Well to my surprise, they did it anyway and did not charge me for it.

One week later, I noticed a foul smell (kind of like antifreeze) when the heater was on. I knew I had a leak either in a hose or the core inside the cab. Apparently this "water" in the spark plug well could have been antifreeze from the heater.

I looked at changing out the heater core myself, but it's getting a bit tricky. Looks like I'm off to find another shop. After the BS the dealer tried to pull over on me, they lost a customer. They treated me like an idiot.


Best of luck

 

My 2000 5.4 was just repaired for the same issue. and yes it was cuased from the heater hose leaking on #4 I had ttwo different machanics tell me this is a common problem:

 

Question:

Can this water in the sparkplug socket cause any real damage to the engine? I assume it will evaporate soon once the problem of the leak is fixed. Is it OK to still drive with the missing and grounding?

Will the heat of the engine help dissipate the water?