1970 Ford Torino Runs hot

MATT1970

MEMBER
1970 FORD TORINO
5.0L
V8
RWD
AUTOMATIC
100,000 MILES

I had a 195 thermostat and it ran fine. But I swapped it with a 160. Now the temp that's at 160 for about 30 minutes then it raises to about 190 very slowly. But once it hits about 190 it stops. I'm looking for something that could cause this or if this is ok for it to do. Any advice? I also changed manifold and carb.

1 Reply

CARADIODOC

MECHANIC
33,871 POSTS

I don't know how you even found such a cold thermostat. That can lead to overheating because the coolant doesn't stay in the engine long enough to absorb the heat and it doesn't stay in the radiator long enough to give up its heat.

Engine parts, pistons in particular, are shaped to fit perfectly when they expand under proper temperature which for a '70 model could be as cold as 180 degrees. 195 is more common. In general, the lower the temperature, the more engine wear will occur, the more emissions will result from incomplete combustion, and the more sludge will develop inside the engine.

You also have to consider the coolant. You need the antifreeze to protect from freezing and to get the necessary amount of additives like water pump lubricant and corrosion inhibitors, but you also need enough water to carry the heat away. Water holds a lot more BTUs of heat than antifreeze does.