1986 Baretta 3.0 mercruiser

[Jamz33]

The owner previous of me got this engine hot and it’s getting water in the oil. The cylinders would fill up with water which led me to find the exhaust manifold is bad. I am not sure about the block. Is there anyway I can test the rest of the engine before I go and buy a manifold? I don’t want to purchase a manifold just to find out the something else is bad as well.

 

[Bondo]

The owner previous of me got this engine hot and it’s getting water in the oil. The cylinders would fill up with water which led me to find the exhaust manifold is bad. I am not sure about the block. Is there anyway I can test the rest of the engine before I go and buy a manifold? I don’t want to purchase a manifold just to find out the something else is bad as well.

Ayuh,...... Isolate the block, 'n pressure test it with 'bout 15psi of air,...
If the head, or block is cracked, you'll hear it, then follow the sound,....

 

[Jamz33]

Thanks for the reply. Is there a video or anything to watch that shows me exactly how to isolate it?

 

[kenny nunez]

Just remove the hose where it is connected to the manifold. If you do not have compressed air then insert the male end of the garden hose in the hose that connected to the manifold and clamp it. Take some vise grips and pinch off the incoming hose. Then gradually open the faucet until the large hose from the water pump to the thermostat housing starts expanding then shut the faucet. I have done it that way many times. If there is an internal block leak the pressure will drop and you might hear it inside the valve cover. Good luck

 

[Jamz33]

Just remove the hose where it is connected to the manifold. If you do not have compressed air then insert the male end of the garden hose in the hose that connected to the manifold and clamp it. Take some vise grips and pinch off the incoming hose. Then gradually open the faucet until the large hose from the water pump to the thermostat housing starts expanding then shut the faucet. I have done it that way many times. If there is an internal block leak the pressure will drop and you might hear it inside the valve cover. Good luck

Ok thank you. If I air it up. What psi?

 

[alldodge]

Ayuh,...... Isolate the block, 'n pressure test it with 'bout 15psi of air,...
If the head, or block is cracked, you'll hear it, then follow the sound,....

 

[Jamz33]

Thanks. Totally missed that part.

 

[Scott Danforth]

it should hold 15 psi with the valve shut off for perpetuity. if it leaks air, you have a leak.

 

[Bt Doctur]

Most 3.0s that have had a severe overheat usually just blow the head gasket and maybe warp the head. A reasonable repair