Hey everyone, this is my first post on this forum, but I have been around the 4.6 world for about 2 years now. I have a 96 mustang GT that has a kenne bell 2.1L, and let me tell you, it is a good time.

Anyways, I wanted to see if someone could shed some light on an issue I am having on my 97 F150. To make a long story short, the truck had a missfire on the #4 cyl. After changing the plugs, injector, coils, and wires, I ran a compression check. I then realized my problem was bigger than I though. I had 0 compression in the #4 cyl. I pulled the head off yesterday. The HG looked to be ok, as well and the exhaust valve. I mean the valves on #4 are black, but they appear to be sealing.

I can still see the factory cross hatch on the cyl as well. I guess my main question is what could be the issue. The valve spring looks good, the lifter looks good, cam is not worn, valve from first sight (not pulled out yet) appears to be ok, cyl looks good (not any wear that I can see), and the cam looks fine.

Should I throw the money into having the head checked out, reaplacing the valves in cyl #4 and replacing the HG, or should I just throw this motor over the hill and pick up a good used one.

Thanks in advance.

 

0 PSI almost always indicates a valve. If it were the rings or the HG, it would show some compression. Are you sure that the piston is moving in the cylinder?

 

turn the head over and pour some oil on the valves and watch to see if it pours on the opposite site.... be sure to check to see if the piston is moving...

 

That is actually exactly what I did last night after I posted this. Although I used kerosene. Filled up the valley and the kerosene had leaked all the way out in about 5 minutes. It was leaking from both the intake and exhaust ports.

I guess I get the fun task of getting the valve springs off and replacing some valves . I remember from my mustang they are a pita to get out without fords special tool. Thanks for the help!

I will also make sure the piston is moving as well, but I am pretty sure it is.