Cylinder head getting hot 2.3L

Keyboardman

Petty Officer 1st Class
Joined
Sep 10, 2015
Messages
360
Hi all, So after finding out my thermostat was opening at 190 instead of 160 like it should, I ran the boat in the water without it to see if that helped the overheating problem. Well, the temp gauge wouldn't even get into operating range so I thought that was a good sign. I opened her up and was running about 3800 rpm on plane. Was running great then after a few minutes, it started missing. Shut her down and checked the engine. The exhaust manifold was cool, the intake manifold was cool, the block was barely warm and the head was extremely warm. Let her cool down and limped it back to the ramp. Could I have a cracked head? Bad head gasket causing water to bypass somewhere in the head? Or, maybe just need to have the rest of the engine up to operating temp like it should be? I'm stumped. Everything in this cooling system has been replaced.
 

kpg7121

Petty Officer 2nd Class
Joined
Aug 25, 2018
Messages
174
Hi all, So after finding out my thermostat was opening at 190 instead of 160 like it should, I ran the boat in the water without it to see if that helped the overheating problem. Well, the temp gauge wouldn't even get into operating range so I thought that was a good sign. I opened her up and was running about 3800 rpm on plane. Was running great then after a few minutes, it started missing. Shut her down and checked the engine. The exhaust manifold was cool, the intake manifold was cool, the block was barely warm and the head was extremely warm. Let her cool down and limped it back to the ramp. Could I have a cracked head? Bad head gasket causing water to bypass somewhere in the head? Or, maybe just need to have the rest of the engine up to operating temp like it should be? I'm stumped. Everything in this cooling system has been replaced.

You may have caused a hot spot in the head because of uneven engine cooling running it without a t-stat. Was the head actually hot or just warm? You may have blown a head gasket running it on plane or worse warped the head. Bet you won't do that again.

Never run a boat engine without a t-stat. The manufacturer don't put them in for show.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,027
The exhaust manifold was cool, the intake manifold was cool, the block was barely warm and the head was extremely warm.

Ayuh,..... Considerin' the water enters the block, flows through the motor, 'n exits at the front of the head, there may not be a problem, but no doubt, no t-stat ain't a good thing,.....
 
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