93 grand am serious problem

I recently put a new head on this 93 GA 2.3 SOHC. It ran fine for about 4500 miles, then one day, went to start it, and lots of racket from under the hood. After a few seconds, it died. I restarted and it ran real rough then died again. I Tore the engine down and found that an intake valve had bent and is stuck open. Upon further investigation, I see marks on the tops of all the piston where the other valves had also hit, it didn't bend those though.
My question is, what would cause this. Timing chain looked good, everything else looked good. Did this thing jump time? If so, why would it do that and how come only one valve bent? How can I keep it from happening again?
Also, How can I tell if a lifter is bad? there was a ticking noise in the upper part of the engine before, I don't know if it is related or not. All the lifters look ok to me but I am not a mechanic so I don't know what to look for. I have too much into this car just to let it go, I need to try to fix it.
Thanks

Sounds like either the lifter or valve was stuck before you started it.

Sounds like either the lifter or valve was stuck before you started it.

Any idea what would cause that? That is why I was wondering if maybe a lifter was bad, but they all look ok.

Hard to say without looking at parts, you should check the lifter bore for wear marks. Ift its ok, either debris got in there or the head had a problem. You said you bought a new head, contact the co that you bought the head from. Sounds like the head wasn't right. :shakehead

Any valves that made marks in a piston are bent. You can test them by standing the head on its side and filling the port with solvent or gasoline and look for the slightest trickle from the valve and seat. Your valves are bent because some how the cam timing is off far enough to cause piston to valve interferance. The only other possibility that interferance takes place is at very high RPM most often caused by down shifting when road speed is too great. It is posible that the valves were bent slightly by high RPM and then when you started the engine one stuck and bent a lot more.

Thanks for your replys. The place I bought the head from is going to replace it but they don't think that the valve was bad. It had about 4500 miles on it before it quit. This car is actually for my daughter. I bought it with a bad head and put the rebuilt one on myself. I really don't think the high RPM thing is what happened, she is a new driver and it is an automatic transmission, but I suppose it is possible. I may never know. I guess I will rebuild again and see what happens. The lifter bore looks good so we will see. All it will cost me at this time is the gasket set. If it doesn't work after this, its off to the bone yard.

Regardless of the circumstances I think the high RPM possibility is not the most likely cause. Some how the cam timing wasn't right, or far more likely cam timing changed and caused the pistons to touch the valves. Take a close look to find how the cam timing might have changed.

When you have the car apart make sure you replace the timing chain, guides and tensioner. When the guides and tensioner wear they cause slack in the chain, which can cause the cams to jump time, and can cause the cams to be off enough without jumping teeth to have the valves hit the pistons. Good luck, the quads can be difficult.

:iagree: with skibum !

That was most likly what caused the timing to be off and hit the valve.
Good thing it died when it did :grinyes: