I had to replace my thermostat on my 4.3 Volvo penta because it was stuck open and would not heat up,took the thermostat houseing off to find a very small thermostat in the top of the housing,I called and got a new one from volvo penta and it was one like the old chevy that fit down on the intake,so i installed it and it works but ,it heats up to about 210 degrees on the muffs before the thermostat opens and it cools back down to about 150 degrees and then it does the same thing over and over,Question is should the temp stay at 160 or go up and down while on the muffs????
