Valve stem stuck open?

[Rochev]

03 Explorer V6, 380k original miles. Bad misfiring. There was a massive intake manifold leak for apparently a LONG time. Besides being nasty, everything is normal looking. After replacing everything ignition and maintanance related and no change, I pulled the manifold off to clean and replace gaskets. I noticed the valve stem on cylinder 4 is dropped down. Here's a photo of that along with what the rest are (closed). How likely is it this valve that's causing the misfiring?

Rest of the valves:
:

Cylinder 4 valve:

 

[CarbonSteel]

Unless I am misunderstanding your thoughts, not all of the valves are going to be closed (or open) at the same time.

Am I misunderstanding?

 

[Rochev]

That's what I thought, but because the rest are closed it seems like that one is bent. I've never seen one open before, they've always been closed. I mean to call them intake valves, that might clear some things up. It does have a constant bank#2 misfire, even though bank 1 had a vacuum leak. I'm thinking because it's had broken timing chain guides for a long time, it could have bent that valve. The chains will rattle when cold or higher rpm but runs ok otherwise. Been that way for "a long time".

 

[atikovi]

If the cam lobe for that valve isn't on it's base circle, the valve will be open to some degree. Why not turn the crank and see if it closes?

 

[Rochev]

I turned the crank quite a bit and it opened more and closed a little. I'm not 100% sure on it. Just replaced all intake and egr gaskets with no change at all. It REALLY did not want to rev above 4500rpm. Smoke tested it and the intake isn't leaking anymore but the holes on the underside of the EGR valve smoked as before. Not sure on that one either. No codes for egr, just "multiple random misfires"

 

[atikovi]

Need a compression test next.

 

[Rochev]

That's what I was thinking. I'll have to pick one up hopefully tomorrow, and I'll post here what I get.

 

[philipp10]

You said you rotated the engine and the valve did not close, correct? What part of "did not close" did you not understand? Yeah that's your issue.

 

[Rochev]

Well I did a few turns and none of them moved much. Crawling under the car and getting up to check over and over got old fast.

 

[t1snwrbrdr12]

bump the starter by removing and jumping the starter relay. Then you can watch the valves you’re worried about while it turns over.

 

[Rochev]

Here's the compression:
1-95
2-100
3-92

4-122
5-119
6-119

So I guess suspect cylinder #4 has the best.
Cranked it 7 times each, twice around, battery kept charged. Unplugging the EGR valve doesn't do anything at idle or higher rpm, however there's vacuum in the line. Looks like 18 years of neglect has tired her out!