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Is it safe to run with no thermostat? [Merged 8-7] No, no, no, no.

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GstRacer

20+ Year Contributor
409
3
May 6, 2003
BooneDocks, Connecticut
ya i was wondering if it's good or bad to run no thermostat i know it will run cold witch is good but is there a thing as too clod i also have a blitz 1.3 radiator cap
 
Uhh well you engine is supposed to opperate at a certain temperature...to cold will ruin things and the car wont run right. It would be a horrible highway driver and run at extremly low temps but for around town in hot weather like 100-110 or so it probably wouldn't be bad as the thermostat would be open most of the time anyway.
 
It will suck in the wintertime because it will take the car forever to warm up. It's not that hard to replace and doesn't cost alot. I would just replace it and be done with it.
 
Running cold is not good; the engine is designed to work at a specific temperature. As a clue, one of the things you look at if a car is experiencing poor gas mileage is whether the thermostat is stuck open (i.e. the same as running with no thermostat).

I think what you mean by cold being "good" is the charge air temperature. You want the air going into the engine as cold as you can get it, but the engine itself at normal operating temperature.
 
Yeh a thermostat is no more than 15 bucks from the dealer (thats where you should get it...don't buy a cheapy one to save 2 bucks and then not have a good thermostat) and install it yourself...its really easy.
 
OK, well my car kept overheating because the thermostat wouldn't open. In an emergency just so I could drive my car, my dad took the thermostat out completley and now i"m running a free flowing coolant system. The water temp is actually a lot cooler than normal, and doesn't rise to high at all. My question is, is this Ok to do...i mean if it makes the car run even cooler than normal why do they even bother putting a thermostat in? Thanks in advance....
 
thermostat helps warm the car up to operating temp quickly and working properly should cool the car and keep it at hte set temp
 
You should always run a thermostat in your car, this helps not only warm the engine up, but also allows the coolant to cool off. In an emergency just drill a couple of holes in the thermostat until you get a new one.
 
NOSNUSE said:
You should always run a thermostat in your car, this helps not only warm the engine up, but also allows the coolant to cool off. In an emergency just drill a couple of holes in the thermostat until you get a new one.

if u odnt have one itll cool it off way more htna just drilling holes in it....the only thing its ognna do is keep the engine temp more regulated...running wihtout one will just keep it cold and in the winter may force it into open loop and ur heater will suck
 
OK, so pretty much in the 90 degree weather of the summer its not a big deal. I'm not planning to do this permanantly(actually looked at 2 NEW cars last night) so its just for the time being until I get around to ordering one, or I get a new car. I'm looking for an SUV or 97+ awd talon...

Edit: Sorry for putting this in the hangout, it can be moved to general or whatever....don't know what I was thinking posting it here.
 
I think you could actually overheat from driving without one. The cooling system will not be doing its job and with coolant just free flowing it gives it no time to cool down. If it does not cool down eventually it will keep heating up until BAM! Really hot antifreeze! OMG Ok sorry that was getting lame, but true that your cooling system will not be doing its job. I would get one in asap.
 
DSMRevolution said:
I think you could actually overheat from driving without one. The cooling system will not be doing its job and with coolant just free flowing it gives it no time to cool down. If it does not cool down eventually it will keep heating up until BAM! Really hot antifreeze! OMG Ok sorry that was getting lame, but true that your cooling system will not be doing its job. I would get one in asap.


WTF? You obviously don't understand how the cooling system works. When the thermo is closed, the water in the system is circulated through the engine only. When it's open, it goes to the radiatr to col down. If it's not there, the radiator is ALWAYS cooling the coolant, so you will run cooler, never hotter.

It's not a good idea to do long-term, since there is a reason your car has a 190 degree thermostat....the engine runs at its peak efficiency at that temp range. Any hotter and you can do damage, any cooler and you run rich.
 
Just go to any parts store and fork over the $8 for a new one. YOu dont need to order it and running without one is not recomended although it is possible.
 
If the coolant is flowing too quickly you can have cavitation and foaming and that will reduce the thermal trasfer characteristics of the coolant. Therfore no thermostat could, in theory, make the car run hot.

That aside, your engine forms moisture inside when it cools and condensates on the walls of the inside. This moisture then is washed down into the oil when the engine is started and then awaits vaporization by internal temperatures rising high enough to bring the moisture to the appropriate corrected vapor point (boiling). If enough moisture is left behind it combines with combustion byproducts to form acids that dissolve in the oil itself. The oil becomes more acidic as the age of the oil progresses and picks on certain parts eventually. Also moisture will corrode other surfaces. So, it's important to get these engines to a satisfying operating temperature as soon as possible. Usually oil pooling temps are about 30 to 40 degrees higher than the coolant temps. This is a generalised statement and can vary with load and engine design but you can see why you want your oil over 212 degrees to boil out the moiture immediately!
If you have no thermostat and the rest of your cooling system works properly you will take either a very long time to reach ~180 or you won't ever reach it. Although you may produce more power it's not going to be good for longevity of your engine components.
 
crazyjoe said:
WTF? You obviously don't understand how the cooling system works. When the thermo is closed, the water in the system is circulated through the engine only. When it's open, it goes to the radiatr to col down. If it's not there, the radiator is ALWAYS cooling the coolant, so you will run cooler, never hotter.

It's not a good idea to do long-term, since there is a reason your car has a 190 degree thermostat....the engine runs at its peak efficiency at that temp range. Any hotter and you can do damage, any cooler and you run rich.

Um no how about WTF back to you because I DO understand how a cooling system works. Think about it, it is common sense. If you have no thermostat and you have coolant running through the block, head, radiator, heater core etc without the thermostat closing then what is the radiator actually doing? Well not much because coolant does not sit in the radiator long enough to actually be affected by the radiator fans and "wind speed" cooling. When the thermostat is closed it is circulating through the heater core also, not just the engine. If it's not there (thermostat), your radiator is NOT always cooling the coolant so you will eventually run hotter. Any hotter then 190 and you will not do damage, but any hotter then 220 you might do damage. On some cars, the radiator fans do not even kick on until the coolant temp sensor sees 227 degrees. Not sure on a DSM what temp, but I am sure I could check on my logger. Hotter engine temp - Better gas mileage and less performance. Cooler engine temp - Worse gas mileage but more performance. Why take the chance of warping something because you have no thermostat and every engine component is running at a different temperature? Spend the $5 and replace the thermostat.
 
DSMRevolution said:
Um no how about WTF back to you because I DO understand how a cooling system works. Think about it, it is common sense. If you have no thermostat and you have coolant running through the block, head, radiator, heater core etc without the thermostat closing then what is the radiator actually doing? Well not much because coolant does not sit in the radiator long enough to actually be affected by the radiator fans and "wind speed" cooling. When the thermostat is closed it is circulating through the heater core also, not just the engine. If it's not there (thermostat), your radiator is NOT always cooling the coolant so you will eventually run hotter. Any hotter then 190 and you will not do damage, but any hotter then 220 you might do damage. On some cars, the radiator fans do not even kick on until the coolant temp sensor sees 227 degrees. Not sure on a DSM what temp, but I am sure I could check on my logger. Hotter engine temp - Better gas mileage and less performance. Cooler engine temp - Worse gas mileage but more performance. Why take the chance of warping something because you have no thermostat and every engine component is running at a different temperature? Spend the $5 and replace the thermostat.

I dunno what to tell you bub, except try it and it will become immediately apparent that I'm right and you're wrong. I speak with the voice of experience.
 
Before this gets personal I'm locking it.

Take you coolant system argument to PM's.

It won't hurt to go without one in the short-run.

Since they are only like 10bux or whatever get one in asap.
 
Yes you do. Without it, the car wont run in optimun temperature. Some people have reported their car running a little rich, some have reported that their car overheats becuse the coolant keeps flowing and its not long enough in the radiator to cool down.
 
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