midexp
Active Member
- Oct 5, 2016
- 425
- Boat Info
- 1999 40' Sundancer
- Engines
- 454 merc
Mercruiser 7.4L Horizons closed cooling. Starboard engine went to 180 yesterday. The coolant recovery bottle is filled to the top (was at the normal fill level prior) and I did not see any coolant in the heat exchanger when I open the cap. I'm guessing the thermostat is stuck and not allowing the coolant to flow through the heat exchanges? And if I replace the thermostat, will it draw the coolant up from the overflow bottle up to the heat exchanger, or will I need to add coolant to fill the heat exchanger?