I have to pull the heads off, I have a stuck (or something) exhaust valve on #3 cylinder. No compression on #3 and when I apply air pressure to it at TDC I can hear it in the tailpipe. Any helpful hints or suggestions would be appreciated .

 

Has the valve cover been removed for a look? Might be something that can be fixed without removing the head....which is going to be alot of work with difficult to get to bolts.

 

No, I have not yet taken the cover off. I know the cover has to come off, I've been procrastinating a little bit. I'll take a look inside the cover tonight and post back.

 

Well, the valve cover is off and all looks normal on the top side. Through the spark plug hole I don't see any damage to the top of the piston. Any suggestions to make this easier would be appreciated.

 

Disconnect the ignition coil electrical connector. Watch the rocker arms for cylinder #3 while you crank the engine. Make sure both valves open and close. Could be a broken valve spring, in which case you do not need to remove the head. Measure valve stem height with the valves closed and compare to another cylnder. If the valves are closing tightly, and still no compression, then it's time to pull a head and investigate.

 

Thanks Captain. Both valves are operating normal as far as I can tell. As far as measuring the valve stem height do I measure the spring height or the rocker arm height?

 

From the valve stem tip down to the surface where the spring sits on the head.

 

I would think that even rocker arm height at the valve would work....something as long as it can be compared to the same on another cylinder. Need to take an accurate measurement.
Another thing to try is to put #3 at TDC and then apply compressed air through the spark plug hole and listen / feel for the air escaping. Should let you know if either valve is not closing completely.

This was how I found that I had a bent intake valve on a 350 chevy once.

 

Like Lanny suggested, All you need to do is measure on two different cylinders. As long as you measure in the same place on each one, you'll be fine. Your first post tells the story... #3 exhaust valve is not sealing. What you're checking for now is a broken exhaust valve spring. The head doesn't have to come off to replace it. If the valve is burnt, the stem is bent, or the guide is tight, the head has to come off.

While the cylinder is under pressure, and leaking out the tail pipe, rap on the rocker arm above the valve stem with a nylon or rubber hammer. See if you still hear air in the tailpipe.

 

I'll try that tomorrow night after work. Too late tonight to work on it, I'm beat.