Thermostat which one to use

not liking the stock stat

letting the car do what it wants with the stock thermo in i just dont like it once its reaches strait up position on the guage it stays there or moves to the right especially at highway speeds. at which point i have to flip the # 14 switch. with the 180 it would at least return to the "n" at times and without thermo completely i felt like i could actually control temps so ive got to say its my radiator even though ita a newer aluminium rad.. its just not able to keep the temps down with out fan interaction be it manually or other

now my w/p is fairly new but i read somewhere the aftermarket pumps from advance and such have less impeller action is this true ? weak flow could likely factor in as well i figure especially at 60/70/80 speeds.....
 
You should never run without a thermostat. Without it the water never has a chance to sit in the radiator long enough to cool down. It will eventually overheat. Let's say your radiator is large enough to deal with it and you don't overheat then you end up dealing with the issue of open loop. If the engine never reaches operating temperature then the system never gets to a closed loop status. Either way running without a thermostat is bad news. IMO.
 
You should never run without a thermostat. Without it the water never has a chance to sit in the radiator long enough to cool down. It will eventually overheat. Let's say your radiator is large enough to deal with it and you don't overheat then you end up dealing with the issue of open loop. If the engine never reaches operating temperature then the system never gets to a closed loop status. Either way running without a thermostat is bad news. IMO.

I thought the open loop to closed loop deal was time based, and engine temp has no impact. BTW, I use a high flow 180 thermostat and fans are set to come on at 188. Coolant temps pretty much stay in the 180s no matter how hot or cold it is outside.

David
 
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I'm fairly sure closed loop is engine temp based.
The thermostat provides a restriction to allow heat to transfer from the engine to the water.

OBD 2 code P0125 indicates that the engine has not reached the required temperature level to enter closed-loop
 
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The thermostat also allows restriction to transfer heat from the radiator to the ambient air. Closed loop is definitely affected by temperature.
 
letting the car do what it wants with the stock thermo in i just dont like it once its reaches strait up position on the guage it stays there or moves to the right especially at highway speeds. at which point i have to flip the # 14 switch. with the 180 it would at least return to the "n" at times and without thermo completely i felt like i could actually control temps so ive got to say its my radiator even though ita a newer aluminium rad.. its just not able to keep the temps down with out fan interaction be it manually or other
I don't have a problem in texas heat even with A/C, but theres a couple of things to be aware of:

1. That small little air diverter below the bumper is crucial. Its the difference between overheating and not. It needs to be angled forward so that air gets shoved up and thru the radiator.

2. And that gap btwn the bottom of the radiator and the frame... lets precious cooling air go by, rather than thru the core. I close it with a flap of old flexible sheet vinyl cut to shape.

Items 1 and 2 are the difference between my black car (with a stock rad) running at the track and not overheating. :) And yes, I need a better rad for that purpose.
 
If you have a tuner (QH, etc), you can change the closed loop "on" temperature setting too. That's another reason I always say to stick with the stock t'stat if you don't have a tuner or a stand-alone fan turn-on system. Assuming a mostly stock car, if your cooling system is up to snuff, it should be able to handle the heat. When you start experimenting with lower t-stats, no t-stat, or putting a gerbil in the housing, you might find a combo that works, but it seems like most folks end up making things worse by changing t'stat temps without changing fan settings.

It can be frustrating, but if your car is overheating with a new stock thermostat, then there is something else that needs fixed.
 
If you have a tuner (QH, etc), you can change the closed loop "on" temperature setting too. That's another reason I always say to stick with the stock t'stat if you don't have a tuner or a stand-alone fan turn-on system. Assuming a mostly stock car, if your cooling system is up to snuff, it should be able to handle the heat. When you start experimenting with lower t-stats, no t-stat, or putting a gerbil in the housing, you might find a combo that works, but it seems like most folks end up making things worse by changing t'stat temps without changing fan settings.

It can be frustrating, but if your car is overheating with a new stock thermostat, then there is something else that needs fixed.

Matt,

What is the stock "closed loop on" temp setting ?

David
 
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