1999 7.4L hissing noise, then no cranking

[4sure]

My boys are out on a trip this week and ran into some problems. They were on a flawless 4 hour trip when they arrived at their destination they noticed a hissing or helicopter like sound from the engine. When they made it to the dock the engine was running rough. Upon trying to restart the engine at the dock it tried to crank, tried to turn, but could not. Oil dipstick was not like a milkshake. Diagnosis being done now as I am not with them. Thinking manifolds (5 years old) What would make the hissing noise? Water in the cylinders?

 

[Strecker25]

I would think a vacuum leak could be a hissing noise? Maybe as simple as a vac hose coming off. Is she carbed or injected?

 

[4sure]

Found the problem, thanks everyone.

 

[src]

Found the problem, thanks everyone.

Don't leave us hanging - what was it?

 

[Larry]

It was a hole that rotted through the head (raw water cooled)

 

[Tonka Boater]

Found the problem, thanks everyone.

Don't leave us hanging - what was it?

Yes, what was the diagnosis? It can help others if we know your symptoms, cause and remedy.

 

[4sure]

We cleaned all the spark plugs on one side of the engine which showed signs of water, tested the exhaust manifold to be sure there was no leak of water into the exhaust, put everything together, started the engine, seemed to run ok. When the exhaust manifold was installed to the block, we snapped one bolt. The next day we took off the top section of the manifold riser and the dry exhaust section was full of water. When the manifold was removed, thermostat housing was removed and a running hose was put into the top of the block, when the engine was cranked water came out from the exhaust port from the last cylinder on the port side. The head had rotted allowing water into the exhaust section of the the head. Remedy: new engine