I have a yanmar 3cyl engine it showed sines of head gasket gone it kept overheating. It has no thermostat in it either.
Gasket was changed and the radiator and block flushed through. Water pump was in good condition and new hoses fitted still without a thermostat.
It boiled and found the radiator was only 20% eficiant. A new radiator was bought and it ran ok for a month. It did have to be topped up with water and I noticed the breather pipe on rocker cover breathing hard blowing steam out and had never seen this before. It then after a month 6 weeks boiled 120 deg. I let it cool and had a look it needed about a liter of water.
Next day I went to start it it turned slightly and stopped I re tried and it turned over and eventually fired up a bit of white smoke . I notised the header tank leak off was going like a fire hose pumping water out .
I suspect the head is cracked ?? any thoughts please.
Gasket was changed and the radiator and block flushed through. Water pump was in good condition and new hoses fitted still without a thermostat.
It boiled and found the radiator was only 20% eficiant. A new radiator was bought and it ran ok for a month. It did have to be topped up with water and I noticed the breather pipe on rocker cover breathing hard blowing steam out and had never seen this before. It then after a month 6 weeks boiled 120 deg. I let it cool and had a look it needed about a liter of water.
Next day I went to start it it turned slightly and stopped I re tried and it turned over and eventually fired up a bit of white smoke . I notised the header tank leak off was going like a fire hose pumping water out .
I suspect the head is cracked ?? any thoughts please.