"This one even has my mechanic
"This one even has my mechanic stumped! I have a Merc 302 in which the top end (heads, carb, hoses, gaskets, etc.) has been rebuilt or replaced. We’re having temperature problems though: while underway the temp continues to swing from 120 to 160 in about a 30 second interval. The thermostat is a new 140 (we’ve tried two others), and the housing around it has been replaced. Placing my hands on the elbows, while underway, I can feel the temperature change happen. I’ve read on this site about a thermostat put in backwards and I will check that next. I will also purchase an infra-red temp sensor to check what’s going on in other areas. But until then, has anyone ever heard of this before?
Other details which may be relevant: The oil pressure is between 25 and 35. First time out since the rebuild I blew the port side exhaust hose – the port side of the this engine was hot! I think they had the water hoses to the elbows hooked up incorrectly. Next time out I blew the head gaskets. Funny thing it was – they both blew in the same place on opposite sides of the engine. Faulty and inexpensive gaskets were the given reason. And now this. At present, the mechanics are reviewing their work and we’re both searching for answers. Any ideas would be much appreciated."
"This one even has my mechanic stumped! I have a Merc 302 in which the top end (heads, carb, hoses, gaskets, etc.) has been rebuilt or replaced. We’re having temperature problems though: while underway the temp continues to swing from 120 to 160 in about a 30 second interval. The thermostat is a new 140 (we’ve tried two others), and the housing around it has been replaced. Placing my hands on the elbows, while underway, I can feel the temperature change happen. I’ve read on this site about a thermostat put in backwards and I will check that next. I will also purchase an infra-red temp sensor to check what’s going on in other areas. But until then, has anyone ever heard of this before?
Other details which may be relevant: The oil pressure is between 25 and 35. First time out since the rebuild I blew the port side exhaust hose – the port side of the this engine was hot! I think they had the water hoses to the elbows hooked up incorrectly. Next time out I blew the head gaskets. Funny thing it was – they both blew in the same place on opposite sides of the engine. Faulty and inexpensive gaskets were the given reason. And now this. At present, the mechanics are reviewing their work and we’re both searching for answers. Any ideas would be much appreciated."
