Water Temperature Gauge

[Mr 5 0]

Originally posted by Mustangbelle306

...after installing 160 F thermostat, it still idles around 195-200 F, but at highway speeds it sits comfortably between 170-180.

I understand that at higher speeds the incoming air will cool the engine, but shouldn't it be running at 160 at that point? And is a 20-30 degree difference between idle and cruising normal?

The thermostat opens at 160 but it won't close up again on a normally running engine. When you idle - and have no airflow - the temperature will naturally rise, then drop when the airflow increases. As you have a modified engine, it will run somewhat hotter than 'normal' at idle.

Just as when you drive normally and shut the engine off for five minutes then re-start, you'll see the temperature somewhat higher than normal as the remaining engine heat is trapped in the cooling system with nowhere to go until it can just naturally cool down.

An electric fan would give you lower idle temperatures, if this is a real concern.