I recently bought a 97 F150 with the 4.6 V8 with 100,000 miles on it. After driving for a very short time it started stalling on me when I came to a stop and would idle really rough. I read this board and changed the spark plugs and that really helped. The number four plug was really wet with a watery oil. (It was a hard job getting to the plugs but the really hard part was snaking the wires back around and then putting those holders back on.) Anyway it runs much much better however it still will idle a little rough. I'm going to do several other things but want to change the fuel filter. Can anyone tell me where that is? I've read it's on the passenger side frame but can't find. Can someone be more specific as to it location. Also what is this tool that I will need to change. Thanks for the help

 

Fuel filter located on Drivers side. On the frame under drivers side door. "Fuel line disconnect tool" is available at NAPA or other auto parts store.

Good Luck,

Bill

 

What do you mean by "watery oil"?

 

If the watery oil was on the outside of the plug, its probably coming from the heater hose leaking. I've seen this before, and some trucks don't suffer from this, but the heater hose above the engine and the #4 plug will seep alittle water and short out the coil. This could be your problem.

I have 50k on a 2000 5.4 f150, I'm noticeing the idle is a little rough sometimes, and has gotten progressively worse. So much for 100k tuneups.

Chris

 

On the outside of the plug there was definately oil but it looked as though it had been mixed with water as is was very thin, etc. That's about the best I can describe. Thanks

 

Now that you bring up the subject of coils I do have a question. On my 4.6 it appears to me that I have a spark plug (actually 8) attached to the spark plug is the spark plug wire and the other end of the wire is attached to a coil (at least that is what I think it is) It appears to me that I have two coils where four of the plug wires attach to each one. The reason I'm confused is it seems as though people are talking about each spark plug each having it's own coil. Are we talking semantics here? It seems as though there are only two coils with four attachments each. Is each attachment point considered a coil?

I have read here where something could leak into the number four plug and was interested in that theory. However I'm not sure how it could short out the coil when (I think)the coil is located at the front of the engine. I really do appreciate all the advice anyone can give me on this.

I really think the rough idle is coming from the EGR valve as someone has described the symptoms of that going bad as exactly what is happening to me. (Coming to a stop and having the engine drop to around 400 rpms then surging to 1200 to drop back to 400 and almost die, over and over again)I tried to take the EGR valve off the other day but couldn't get one of the bolts loose and wanted to wait until I had someone around to help that knows what they are doing.

I thought I would try all the simple stuff first (changing the air filter, fuel filter, etc) before changing the EGR valve, O2 sensors etc. Anyway I'm getting off topic here. Thanks to all who have written this is a great forum. Any education on the coil issue would be appreciated and any other ideas as to the problem also.

 

I have two coils where four of the plug wires attach to
>each one. The reason I'm confused is it seems as though
>people are talking about each spark plug each having it's
>own coil. Are we talking semantics here? It seems as
>though there are only two coils with four attachments each.
>Is each attachment point considered a coil?

Yes. You can't see the coil. The black box has a coil in it for each wire / plug. It is a semantics problem, all right.

>I have read here where something could leak into the number
>four plug and was interested in that theory. However I'm
>not sure how it could short out the coil when (I think)the
>coil is located at the front of the engine. I really do
>appreciate all the advice anyone can give me on this.

It will short out the spark plug boot, meaning you have current go from the wire to the head / surrounding metal. It won't short anything at the coil itself.

Cheers, George

 

The earlier 4.6s had a coil pack at the front of each cylinder head with wires to the plugs. The later ones have a coil mounted on top of each spark plug with no visible plug wire.

 

Thanks again guys. I have been reading my Haynes repair manual and they do refer to my coils as a "coil pack" They are located up by the heads.

Hate to keep asking all these questions however thought I'd try one more. When I first got the truck it stalled and idled rough and the rpms would go down to 400 and then shoot up to 1200 etc.

After the spark plug change it still idles rough like it wants to almost stall but doesn't. However the rpms don't fall or shoot up like they were. The rpms stay right about 600 or so. Any guess on the cause? No idiot lights to go off of. Thanks again.