Don't trash the engine
for the sake of a head gasket
or even a cracked head. Blown head gasket may effect the compression
reading. There are a several ways to determine a blown gasket.
If you are not familiar with engine
maybe hire a mechanic
to diagnose it for you.
One way to diagnose is to put a pressure tester on the coolant
to 14 psi and let sit. Take out injectors or glow plugs. Crank over engine. If coolant/water comes out you have a blown head gasket. Another way is pump
up the cooling
system , let sit over night then try and hand crank the engine over. Careful as the engine may be hydrolocked. Unlock by removing glow plugs or Injectors then cranking over.
Another way is a leak down test but you will need a compression
tester fitting, a leak down tester and compressed air to do this.
Another way is to fill the cooling
system and leave the cap off then crank the engine over. If water
shoots up into the air you have a head gasket or head issue. This only works on BIG leaks
Another is to leave the coolant
pressure gauge on and run the engine. It will slowly build pressure due to normal thermal expansion but once up to temp it should hold steady. If you warm up the engine and with it running the pressure continually builds up then yes, you have a blown gasket or warped or cracked head. This is a good way to check for small leaks
If you have a blown head gasket you should start to see the engine oil
start to look like a chocolate milkshake. This may take a couple of hours or even longer to happen.
out salt water
smoke by running the engine without the raw water
going to it for about 2 to 3 minutes when the engine is cold. If the smoke stops you have a problem where raw water
is getting into the engine somewhere. Possibly at the mixing elbow
. Watch the exhaust
hose doesn't get too hot when doing this but you can run the engine for short periods without raw water
going to it.
Possible you de-tempered the piston rings but I kinda doubt it. You would need to get the head off to tell you if then fixing the boat
is worth it or not by looking at and measuring the bores.
NCBoatrx has a good plan. Ditto pete7 Look at Youtube "Bums on a boat" who just took their head off of a MD2030
which is the same beast. It's really not hard to do.
Does the smoke smell like oil
and leave a sheen on the water? Or does it smell like steam from a kettle? Or smell like diesel
and also leave a sheen on the water?