engine was hydrolocked, now....

[drolds72]

Helping a friend with a 1997 5.7 Gen 2 carbed engine. Got a call saying the starter was grinding bad. Would not crank engine. Removed starter to find that the nose cone was broken off. Rotated engine by hand, and flywheel teeth were not damaged. So next step was to pull the plugs and crank. Starboard bank ok, Port side had water in all 4 cylinders, the most coming out of the inside 2 cylinders. Pulled riser and manifold, riser looked ok, manifold was rust stained with water in inner exhaust section. Compression test next. Installed new starter. Stbd side 155-160. Port side 150 - 50- 50- 150. Usual suspects are cracked head, head gasket, or bend connecting rod. My question: Is there anything else I can do to determine point of failure, or am I at the point where the port side head needs to be taken off for inspection. If its a bent rod, is the symptom the piston not coming all the way up? Next logical step is....?

 

[thumpar]

Try a leak down test.

 

[drolds72]

I have access to a leakdown gauge.... air out the cooling system for head gasket, and out the oil filler for cracked head?

 

[Scott Danforth]

I'm going to go with junk risers and manifold and rusted valve seats and cylinder walls

 

[Rick Stephens]

With a leak down - air sounds in oil filler cap usually broken rings or hole in piston. Exhaust sounds is bad exh valve - carburatur is intake valve.

 

[tpenfield]

You can get an idea if there are bent connecting rods on the 2 middle cylinders by using a straw in the spark plug opening to see if the pistons rise to the top of the block while rotating the engine by hand. If the leak test on those cylinders comes in good for those 2 cylinders, it would also be an indication of bent rods.

You are wise to do ample testing and diagnosis before opening the engine up.

 

[alldodge]

I'm going to agree with Scott. Doing a leak down test will give you more clues to what's happening but in the end the head is still coming off. Just pull the head, rotate the crank and see if the pistons come all the way up with the others.