I have a 1993 Jeep Grand Cherokee 5.2L V8 I posted a question on here before and many thanks, What I had was a bent rod well I took off the head and removed all the valve springs and found that where the bent rod was the valve stems are bent too. What else do I need to do? or can I clean the head up make sure no valve holes are bent, replace the rods and valves and be good to go. I want my jeep running again!!! Thanks
I'd say the timing chain either broke or the cam gear is worn off,cam gears used to be made of fiber rather than steel on older engines. When the cam stops turning the valves stop working and when the piston comes up it then hits any valves that are open bending the valve or push rod or both. If this particular engine is run by a belt and the belt breaks you get the same result. To check this you can take the timing cover loose on the front of the engine and check the condition of the chain and gear.
Valve stems don't usually bend unless the valve hits a piston. I am assuming the rod that was bent was a push rod. The 5.2 engine is not an interference engine, so a cam timing problem would not cause the piston to hit the valve. I suppose that if you way over reved the engine a lifter could have pumped up and at a very high RPM the valves may have floated causing one or more to strike a piston. Push rods do bend for a variety of reasons, but to have a bent push rod AND a bent valve stem I would need more information to give you even an educated guess. You have the head off so look at the top of the piston and see if it looks like it was hit by the valves. Take the head to a machinist and have him check it for cracks and damaged guides. Have him check the valve spring tension also.
