Over heating 454

[bwilson47]

Has any one had problems with over heating on a 1988 Sea Ray Pachanga? There is no blockage in the power steering heat exchanger, the thermostat is new, both the Alpha water pump and the engine water pump are OK. The next thing on the list is the restrictor in the thermostat housing. The Mercruiser's are 454s and the engine temps will climb to around 190 degrees . This is a fresh water boat. Any help in this matter would be appreciated. Thanks

 

[frankiefa]

Overheating 454

I had a hell of a time trying to find the source of overheating on my 1987 34ft express, and it was isolated to the raw water inlet hose on the pump which runs under the engine and had gone soft with age. Under suction, it collapsed and starved the engine for coolong. Other than that, wrong plug gaps can make the engine run hot, or a pressure cap may not be working.

 

[Flying Cloud]

Has any one had problems with over heating on a 1988 Sea Ray Pachanga? There is no blockage in the power steering heat exchanger, the thermostat is new, both the Alpha water pump and the engine water pump are OK. The next thing on the list is the restrictor in the thermostat housing. The Mercruiser's are 454s and the engine temps will climb to around 190 degrees . This is a fresh water boat. Any help in this matter would be appreciated. Thanks

IF fresh water Cooled including Exhaust Manifolds;
FWC 454s can't run very long at High speed and need to cool at
low speed.
Suggest: Raw Water for Exhaust or complete RWC:grin:

 

[Flying Cloud]

Has any one had problems with over heating on a 1988 Sea Ray Pachanga? There is no blockage in the power steering heat exchanger, the thermostat is new, both the Alpha water pump and the engine water pump are OK. The next thing on the list is the restrictor in the thermostat housing. The Mercruiser's are 454s and the engine temps will climb to around 190 degrees . This is a fresh water boat. Any help in this matter would be appreciated. Thanks

Two types of Thermostats; One for RWC and One for FWC :huh:
(RWC has a Large round piece of metal attached to the Bottom Side FWC don't)
Also, Small blocks run High temp Thermostats, Big Blocks don't!
One more Question; Are Both Thermostats 140 degree or 180?

 

[Mike Blake]

Re: Overheating 454

I had a hell of a time trying to find the source of overheating on my 1987 34ft express, and it was isolated to the raw water inlet hose on the pump which runs under the engine and had gone soft with age. Under suction, it collapsed and starved the engine for coolong. Other than that, wrong plug gaps can make the engine run hot, or a pressure cap may not be working.

Wrong plug gaps will never make it run hot.