You are not going to like the answer. But the only sure fire way to to tear down the engine at the very least pull apart the top end that is, the cam and lifetrs and with the oil pan droped you can push it back thru the block and it should fall out. After that the only other way to fix it, is to get a pump block off plate put it on and go with a electric pump.
Gonna have to pull the head and find out what's wrong. Could be a bent valve.
That engine is pushrod, it is the GM 3100 if I'm not mistaken. What are symptoms because bent valves are unlikely.
A bent engine piston is a reference to the piston rod. The piston cannot be bent, but the piston rod can be bent.
yes definitely, bent 4 exhaust valves on my 98, and she was locked up
NO it is an interference motor 180,000 broke timing chain, bent #3 exhaust valve, luckily it must have stopped quickly as no more were bent.
Yes it does if the belt breaks you will most likely need a new engine, because the valves will be bent up.
A bent hammer
Cracked or warped heads, motor block, Bent valves, blown head and/or header gaskets worst case locking up the engine.
it did in mine it bent 2 valves and i end it up replacing the head on it
The year and engine size would help but you may have a bent valve or bent pushrod for # 4 cylinder if that is the only cylinder that has 0 for compression.
the valve bent because the piston hit it, due to a weak valve spring or over revving the engine
Any decent alignment shop or place that sells and installs tires can remove the wheel, remove the tire, and check the wheel to see if it is bent. If it is bent very badly, just jacking up that wheel and spinning it by hand, you can see that it is bent.