96' Exploder, needs a bit of help.

[paul84043]

Hello all, new member first post with a question.
We purchased a 96 Exploder with the 4.0l V6 from the original owner that we know pretty well. It's in exceptional condition, but had been throwing a Cylinder 3 misfire code for the past few years, even though it did not seem to run any different.
They told her it might be something to worry about, but it also might be crappy gas as they didn't drive it very much. (literally only a couple times a year)
It was running fine when we picked it up, but within a month, set the code again, and then the kids started complaining that it had no power.
I replaced the plugs and wires, all the usual stuff, but the plug in cylinder 5 felt "bad"..kind of mushy and scary.., I'm almost afraid it's stripped or broken and I did not remove it. The cylinder is still firing normally.
I took it to a local garage that I trust for a diagnostic and they confirmed the Cylinder 3 misfire. They did not mention anything about cylinder 5.
They also confirmed, the spark plug is firing and the injector is working, leaving me to a potential broken valve spring or stuck valve....something along those lines.
The oil is clean, coolant is clean and it does not burn anything beyond a little oil that you would expect from 160k miles, so I don't believe I have a blown head gasket.
I'm left with the conundrum...do I just pull the heads and look into a rebuild/exchange since I'm having potential issues on both heads, or does this sound like it might be fixable in place?? I have worked on many vehicles, but am looking for thoughts from Explorer owners specifically.
How much of a PITA is pulling the heads on the 4.0 V6?

Thanks for any thoughts...

Paul.

 

[lobo411]

How much of a PITA is pulling the heads on the 4.0 V6?

Thanks for any thoughts...

Paul.

It's easy. Not a 5 min job, but nothing a backyard mechanic can't handle.

When I get a new (used) car, I assume that the last owner did no maintenance at all. I replace the upper/lower radiator hoses and do a coolant flush, change the transmission fluid and filter, replace the fuel filter, check and most likely replace all brake pads, change the oil, install new spark plugs, install a new belt, and at 160k mi I wouldn't hesitate to replace the plug wires and all oxygen sensors too.

If you do this, then there's no guessing about when the last time was that X was replaced. If you do it yourself, you're talking about a $300 max investment. That's nothing.

I wouldn't pull the heads. If you're scared to pull a plug because it feels "mushy," then you need to deal with that first. If it's broken, then it must be fixed even if the car is running perfectly fine. If it's not broken, then you can inspect the plug for signs of anomalies.

 

[koda2000]

if it only throws the code a couple if times a year and runs okay i wouldn't worry about it. my '01 SOHC 4.0 did this for several years. it would only throw the code once in a while and you never felt a miss. i could be wrong, but i seem to remember reading something here about a software change for this problem. don't recall what year it was for though.

 

[paul84043]

Hey, thanks for the replies.
My issue now is that Cylinder 3 IS dead. You can feel the loss of power and hear the slight miss and the truck will not go over about 55mph (according to the kids before I told them to park it). The mechanic verified that Cylinder 3 is not contributing...
I'm at the bare minimum, going to have to pull the valve cover and see if I've got a broken spring. I was just wondering if there are any major issues to know about when pulling the heads...

 

[deweyville65]

First thing is to do a compression test. Determine if in fact if #3 is dead. One thing about it is, the valve cover is easy to get to on that side of the engine. The OHV engine is bad for wearing out the rocker arms and pushrods. I had to change the left bank (4-5-6) on mine when I got it. I really should do the right bank (1-2-3), but it is running quite well. In my opinion, don't go looking for more trouble than you already have. Easiest thing first.

 

[paul84043]

Good advice, I'll pull the cover and start there.
Thanks...

 

[Dave 1955]

Like was said do a compression test before you pull the heads and get back to us.

 

[lobo411]

Good advice, I'll pull the cover and start there.
Thanks...

The valve covers are a pain. You do almost all the work of pulling the heads.

 

[paul84043]

Okay, that's more what I was looking for. Though I have a feeling I'm going to be getting dirty on this job one way or another.

Thanks.

Paul