Understanding Thermostat Temps

[Bcon]

So question, Could running a 160 thermostat cause your car to overheat at idle in traffic. Mine does 440 mild cam internals etc. It runs 180 while moving all day but as soon. As I stop and idle it climes. My theory is since I have a 160 in it, it does not allow the coolant to stay in the radiator long enough to cool it. Thought? I bought a 180 i am going to try before replacing the radiator

 

[Ron H]

At operating temp, whether a 160 or 180, (if not faulty) the stat won’t make any difference, they open and stay that way until coolant drops below the designed stat temp.

 

[themechanic]

The 160 or 180, etc. is the temperature the thermostat begins to open.

 

[Bcon]

I know but in theory the shorter time to reopen, the shorter time the coolant sits in the radiator cooling

 

[HawkRod]

I see discussion about this regularly, but there seems to be a misconception that a thermostat can help a car cool better. That is wrong.
For example, if you have a 180* thermostat and your car runs very hot and/or overheats, changing to a 160* thermostat DOES NOTHING. The problem is that your cooling system cannot adequately shed enough heat. (Without getting into too many details here, a common issue is lack of a fan shroud - it is an important device!)
On the other hand, if your cooling system has excess capacity to shed heat (this is what we all should have), then the thermostat keeps the engine at the temperature dictated by the thermostat. So a 160 will run a few degrees above 160, a 180 will run a few degrees above 180, and so on.

An argument can then be what is the ideal temperature to run an engine. Is a 160* thermostat better than a 180*? This can be a good argument to have over a few beers - you'll get lots of opinions. All I'll say to that is I run a 180* in my Road Runner.

 

[Some Car Guy]

A 160 can make a difference if it is open fully and the system can maintain a certain temp. A 180 is cooler by far than a 195 in my car. Really shouldn’t be if the theory holds true on “equilibrium.”

 

[khryslerkid]

Your cooling system capability will be the end result as to how hot it will run. Along with timing and what fuel your using.

Thermostats just control when the coolant starts to circulate.

 

[Ron H]

I use a 160, although I’d be fine using a 180. All the stat does is open or release water from block sooner or later (160 or 180) to flow through the radiator. In cold climates, a 195 is nice as the block water will heat up more before being run through the cooling system to give more heat and defrost quicker. Motor will reach operating temp sooner. Not a need in warm weather though some want their engine reaching operating temp sooner.

I had a debate with a buddy who thought it nice to remove the stat and run it that way. The stat does control water flow, removing the stat increases flow or speed through the radiator which can inhibit the radiator from doing its job. He eventually had some overheating problems when caught in a traffic back up and reinstalled the stat.

 

[Pops1967GTX]

A few years back , I purchase 2 Mopar 180’ thermostats. I recently replaced with new hoses etc. I tested the old and new. Not having the correct timing and fuel ratio. Tends to run too hot.

 

[RR Fan Dan]

So question, Could running a 160 thermostat cause your car to overheat at idle in traffic. Mine does 440 mild cam internals etc. It runs 180 while moving all day but as soon. As I stop and idle it climes. My theory is since I have a 160 in it, it does not allow the coolant to stay in the radiator long enough to cool it. Thought? I bought a 180 i am going to try before replacing the radiator

I know but in theory the shorter time to reopen, the shorter time the coolant sits in the radiator cooling

If your coolant is not moving through the radiator than it is getting hotter. It needs to move to dissipate heat. The coolant needs to move.