URGENT: rocker arm stud busted. Help!!
You could "just replace" the stud, but you would continue to worry about what caused the problem.
looks like you are running 3/8 studs, it takes a lot to break them. No damage to the rocker arm? Any sign of binding on the push rod?. Pull the coil wire, turn it over a few times, check for cam lobe damage, is the push rod moving?
The hollow sound you heard, "probably" was the push rod, bumping into the valve cover, after the rock/stud assymbly failed. Check inside the valve cover for marks.
It might be that the stud just failed, it is unlikely but it happens. The other posts, about valves contacting the piston is another possiblity, usually you notice it pretty soon after first firing up the engine...or later at higher rpm, from valve float-your engine has been running for some time?...of course it could have fractured earlier and is just now getting to the point of failure. You say it is a "clean" break...take a close look at it, see if maybe some parts are stained more. If its been cracked for a while, it might show more discoloration, then a shinier part where it just failed.
If you can pull the spark plug and get one of those flex scopes inside, you could take a look around for damage. Or you could pull the coil wire,put a compression guage in the spark plug hole, turn it over a few times to see if the you have a leak...that could give you an idea of whether the valves have been damaged. Shor of pulling the head and going through a full diagnosis, these are the best ideas I can come up with. check all the othter studs and rocker too, you might have some geometry issues...push rod length, if it is too short, could allow the rocker arm to hit the stud...usually it gets noticed right away...but if could happen over time.
Just some ideas you might be able to use.
[ This Message was edited by: Beoweolf on 11/3/02 6:57pm ]