4.3 V-6 Temperature fluctuates from 170-200

[Ryan Ellefson]

Hi All, Bought a 1997 185 and the temperature gauge fluctuates while cruising from 170-200. The needle just goes slowly back and forth. Never over 200 but back and forth. Engine speed makes no difference? Any help much appreciated.

 

[blaster]

It could be an improperly installed or bad thermostat. If the thermostat is installed upside down the temperature will jump around. The thermostat sticking is another possibility.

 

[atrick]

Change the thermostat, had same problem with one of my engines in my boat, stat was sticking.