Thermostat

[jrsick]

captains, anyone have recommendations on when to replace the thermostat in a mercruiser? I've got a 2001 3.0.
Temp has been fine for the 3 seasons I have owned the boat. I want to avoid problems but also not change components unnecessarily.
Really enjoy the Maxum forum. Great info that has helped me avoid problems and enjoy the water!

[mcoffey]

I replace mine when I winterize each fall. It is a bit overkill but the thermostat and gasket kit is only $20. I would rather spend a bit extra each year and be confident that all is good then re-use the thermostat when it was out and easy to replace.
When I winterize I remove the thermostat housing and pour RV Antifreeze into the block until full. I then put in new thermo and gasket and bolt the housing back up. Then in spring, I just put it in the water and start it, nothing to do but connect battery and go. Simple enough

[pascavone]

if it works, don't fix it.......

[CountryME]

The wise-***** answer to this is replace it when the overheating alarm goes off and/or your temperature gage shows the motor running too hot or too cold. The 4.0 answer is from mcoffey, that is cheap insurance to be sure you will have no issues.

-JP

[jrsick]

Thanks for the replies. Owner's manual recommends removing thermostat to winterize as per mcoffey's suggestion, then states that you should put the old thermostat back in the engine only with a new gasket. I think my initial plan will be to order a new thermostat and 4 gaskets. I'll winterize by removing the thermostat, replace with a new gasket annually, and a new thermostat every 5 years.