Will a Car Run Hotter Without a Thermostat? (1 Viewer)

[Jkm]

For years i Have Removed The Thermostat to allow my Vehicles to run Cooler and It Works ! The Last Car That I Did this With was my 1995 Toyota Celica, I Bought it used with around 125K miles on it I Drove It For 5 Years Without The Thermostat, It Ran So Cool All The Time, Granted the Heater Did not Work Well But I Live In sunny Calif where the teperatures Dont Really Get That bad Outside ! A Cooler Running Motor Will Outlast A Heated Motor 2 to 1 NO FRIED HEAD GASKETS ! I Sold The Car with Double the mileage for the same price I Paid for it 5 years earlier ! And It ran SWEET !

 

[Jkm]

Also the thermostat primarily serves the Heater Function, Thats its primary purpose, If you dont care about your cars heater working well, than removing the thermostat will keep your motor cooler in most cases

 

[Output Shaft]

The FJ60/62 engines with today's oils are designed to run optimally at 190º F.
190º F seems hot to the touch but it's not too hot for the oil or the metal. It is the ideal temperature.

1. Will the engine run cooler than the specified 190º F without a thermostat? Yes. Up to a point. Then the engine will run hotter because the bypass circuit is always open.
2. Is running cooler than 190º (or 180º F) better for the engine? No. (Google it)
   
3. Will removing the thermostat reduce the cooling efficiency of the radiator? Yes in hot climates.
   
4. Will removing the thermostat cause the engine to run inefficiently? Yes in cool climates.
   
5. Will removing the thermostat increase wear on the engine? Yes in cool climates.
   
6. Will removing the thermostat lower MPG? Yes.
7. Will removing the thermostat in searing hot desert weather be better for the motor? No. 190º F is the ideal temperature. The thermostat is wide open once the coolant temp reaches approx. 190º F. Once the thermostat is wide open, the bypass circuit is closed...unlike when the thermostat is removed.
8. Does a cool running engine promote sludge? Yes.

Cooler than specified is not better, it's only cooler. The correct temperature is the best. The only way to achieve that is to have a thermostat installed.

 

[Seth S]

Easy thing to test. Put together a test loop with hills and highways and warm up your truck. Then go drive it with and without your thermostat and see which works better for you. In my experience vehicles ran hotter without the thermostat.

 

[brownbear]

three pages and beating this to death lol....
Any time one sticks open i never get to temp. Never removed one.

 

[Elbert]

no need to remove any magic parts from the cooling system.

 

[klinetime574]

I’ll just throw in my 2 cents... we all know the infamous o-ring being left out is basically running a stuck open thermostat. Pretty important to have a thermostat IMHO.

And FWIW my 5.7 Tundra had a bad thermostat. Never realized it because the truck was new to me. It started throwing codes and CEL for not warming up within the normal time window. Heater was hot. I replaced the thermostat. Fixed the check engine light, heater was hotter, and my MPG went from 12 to 15.

Run a thermostat.