Cummins 6BTA running hot

[Bradlesh]

I have a 1988 Cummins 6BTA engine that gets up to 200 degrees very quickly, even at idle. I changed thermostat to 160 degree and changed impeller. Still runs hot. While trying to diagnose issue, what is next likely issue?

 

[High Wire]

How is the water flow out of the exhaust?
Do you have a white water vapor trail following you? More than a couple feet is excessive.

 

[stone beach]

check the temperature of the head with IR gun, might not be 200 at all

 

[C lectric]

The cooler T.S. change won't help but leave it now.
THere is a LOT to your system.
If getting hot at idle then is strongly suggested you need to deal with the heat exchanger, pull it and get it cleaned.

Yes, the seawater side can cause overheats but from your minimal description of what has been done it is likely lack of service of the coolant side. The heat cannot even get through the scale buildup to get to the seawater. Scale can build up on both sides, seawater and coolant, of the heat exchanger tubes.

I also posted my tome below which will save me a lot of typing. If you still have questions then ask. But read through first.

 

[Bradlesh]

How is the water flow out of the exhaust?
Do you have a white water vapor trail following you? More than a couple feet is excessive.

i have water coming. i get some white smoke but not much at idle

 

[Bradlesh]

FOULED HEAT EXCHANGER
"Coolant side problems usually present by a fast and often violent overheat under load often spewing coolant out. If caught in time the cool down will be slow, taking a long time."

thanks for this. the above statement from your doc accurately describes what happened