Stuck valve?

[grunt]

I have one dead cylinder in my AMC 304 engine. It is getting spark. No compression with a gauge even when adding some oil down the cylinder. Do I have a stuck valve? I'm thinking its not a burnt valve because all my spark plugs looked decent . I pulled the one valve cover and I see all the rockers moving up and down on the suspected cylinder. If the valve is stuck do I hit the top of the valve stem with a hammer? Any info would be appreciated.

 

[CJ]

If the valve is stuck or bent you should be hearing all kinds of lifter rattle / tapping because of lack of preload on the spring. How much play is in the pushrod for the valve in question?

 

[mylittlecj5]

Could be a hole in the piston or cylinder wall....

 

[grunt]

If the valve is stuck or bent you should be hearing all kinds of lifter rattle / tapping because of lack of preload on the spring. How much play is in the pushrod for the valve in question?

I hear maybe a little ticking. I have headers on with flowmasters.... Last night I gave the suspected valve a couple of taps of a hammer and tighten down the rocker real good. Button it up and it was dark outside so today I will give it a shot. My understanding is a stock AMC 304 push rod can not bend a valve because there is always valve and piston clearance. ....I believe there was a slight spin of the push rod for play. I hoping maybe it is carbon buildup. Any more insight is appreciated...

 

[grunt]

Found out I have a burnt intake valve. Should I replace the lifter on that valve also? Thanks...

 

[dpuck]

If they are all working properly and are not dished out on the bottom, no. I f so, I would replace them all.
By the way, while you're at it, I would pull the other head and send it to the shop as well.

 

[CJim7]

Cams and lifters need to be broken in together. Dont mess with the lifters unless you really have to. If it's still oiling, dont worry about it.

 

[grunt]

Thanks CJim7 and dpuck for the replies. I did a compression test on the other head and all cylinders are at 140 lbs. I can tell someone else has been in here because the gaskets are Fel pro. I'm going to get a new valve to replace the burnt one and lapped all the valves on the head that is taken off and button it up. What caused that valve to burn up?...