I noticed that my raw water
cooled temperature gauge was going up and down few days ago. I replaced the impeller and found no improvement. As i took the thermostat cover off I noticed the little by pass hole on the bottom was plugged. I pushed a an awl thru it and got it open partially, Today I drilled the hole. I am waiting for a new thermostat to arrive in a day or two. As I am checking into the cooling
system further I found two opposing stories about the by pass hole. Some say it should not be open on a raw water
others have done the same as I did today with a drill? Does anyone know who is right. The awl did penetrate with a hammer tap so I assumed that it was carbon. If it suppose to be plugged how does the water
get around until the thermostat opens?