engine trouble - couple questions

[Katemma Life]

Today, engines started fine / ran fine out of the inlet at 1000 RPM. Got to open water and throttled up to 3000; port engine just shut off. No smart craft alarm or anything. It wont start back up. Starter motor turns the engine over but then makes a noise and stops

mechanic pulled plugs. was a slight hissing sound like air was being released. Compression was good in all cylinders. plugs show evidence of water infiltration.
says its an internal leak.

Says best case its a head gasket / worst case I need a new engine: $5k vs $22K

First - I have no idea how this happened. There was no 'incident'. it was running fine.. anyway..

Is there any good way to diagnose further so I dont replace something that could get fixed?
understand this might be too technical for this forum but figured I'd ask..

 

[scoflaw]

Pressurize the engines water side passages. Don't take anything apart yet

 

[Timeflys]

Was fuel getting to the cylinders?? I had an issue where the engine ran fine until the fuel pump quit...

 

[Katemma Life]

fuel pressure is good.
I took the plugs off and fogged the cylinders. I drained the block.
QUESTION = if I go to start the engine with the block drained (and its a bad intake manifold) should the engine kick over or is there too much residuel water in there???

 

[Espos4]

With the block drained, spark plugs removed and the serpentine belt removed to prevent the raw water pump from spinning, the motor should spin freely and expel and water from the cylinders.

Disabling the fuel injectors would be a good idea too.

 

[Espos4]

You can start the motor briefly with the serpentine belt removed and the block drained.

 

[Katemma Life]

OK. thank you.
So.. I suppose pressure testing the water side of the engine is the key correct?
Already talked to 2 guys who cant do it.. guess they dont have the equipment. Anyway to jerry rig this with my compressor?

 

[scoflaw]

Sure is. Cap off the 3 outlets on the t-stat housing. 2 small hoses that go to the ex. manifolds and the big one that comes from the raw water pump. Take off the 2 sensors that screw into the t-stat. Put a schrader valve in 1 and a gauge in the other

 

[Katemma Life]

OK
25 PSI? watch it hold there...

 

[scoflaw]

Sure, or a bit less.

 

[Katemma Life]

mechanic came; performed leakdown tests in each cylinder. everything passed with acceptable leakage. All pistons move fine. all spark plugs are fouled. again, he had noted water droplets on a couple of plugs when he pulled them initially.
we're going to replace plugs, cap & rotor and try to start it.
I didnt do the pressure test on the exhaust / water side - he wasnt in favor of it for some reason.
he doesnt know whats wrong. says maybe water in the fuel...
So, good news mostly but also frustrating that cant figure out the root cause.

 

[Thornton69]

Dump the fuel filters into a clean container to quickly identify them as the source of water.