I know it's closed when you first start up the car so that the engine can quickly become warm and then opens when it reaches operating temperature but is it okay to be without a thermostat in hot weather? It's an ASE question out of my book. My answer off the bat would be "why be without the thermostat? It can't hurt to have it". But what's the answer? Probably would be alright right?

 

Unless you want your car to overheat then it's probably not "ok".

 

If you run without a t-stat, coolant has an open cirle to flow in. That means it (coolant) doesn't stay in the radiator long enough to cool down, so the engine will progressivly get warmer.

 

I don't think I understand the function of a thermostat then.
Because if there was no thermostat, then coolant could freely travel through the radiator even before the engine reaches operating temperature. So the way I see it, not having a thermostat will only prolong the "warming up" of the engine because the coolant is not heating up as rapidly. Can you explain overheating without the thermostat for me though, thanks.

 

I pretty much explained it. But here it goes in mroe detail:

The thermostat is essentially a temperature operated "switch." When the temperature of the coolant gets to a certain point (the t-stat setting, say 195°-or the factory temp), it opens, allowing coolant to pass through. At all times of engine operation, there will be coolant in the block and heads, hoses, and radiator. When you first fire up the car, the coolant will not circulate completly, due to the stat being closed. Once the coolant in the heads and block have reaced the t-stat temp, the stat opens, allowing free passage of coolant. This sends the warmed coolant that has been sitting in the block to the radiator, and draws the cold coolant from the radiator into the block and heads.

Since heat flows from the hot areas to the cold areas, this means that the colder coolant, fresh from the radiator, will draw out more heat and cool the block. Likewise, the hotter coolant that is now in the radiator, will release the heat and cool down. However, time is required for this to happen. This time is "bought" by the thermostat. Once coolant has flowed again, and temps drop, the stat closes, allowing heat to transfer both from the block to the coolant and from the coolant through the radiator.

If you did not have the stat, coolant would just flow at an un-governed rate. This means that the coolant would absorb the heat from the engine just fine, however, because the stat would not be present for it to isolate and cool, the coolant would have little to no time to release the heat. This would make for slow and residual heating that would eventually, well, overheat.

 

OHHHHHHHHH

In your first post, I knew what you were saying, but didn't understand it. You definitely gave me the right answer, and just now explained it perfectly. So the thermostat is always opening and coming close to closing at times, not just opens during operating temperature and that's it...ALL MAKES SENSE NOW.

The answer to my questions is "No, you NEED a thermostat"

Thanks Stekman

 

That's not true. If the coolant was removing heat the temp gauge would reflect it. Since the temp gauge reads cold, that means the coolant is not removing heat since it's going through so fast it doesn't have time to absorb the heat. Think of it as holding your hand over a flame. Your hand gets hot because it's absorbing the heat. If you move your hand back and forth over the flame you don't feel the heat, because your hand is not there long enough to absorb any heat. Now, since your coolant is not removing the heat, where is it going? Good question...It's going into all the internal parts of your engine. If you've ever removed the valve cover from an engine that hasn't ran a thermostat, you would see caked deposits of oil. Why? Because the engine got so hot it cooked the oil. So your temp gauge may read cold, but your engine is cooking. Remember, the coolant's main purpose is to maintain cylinder temp. The more heat removed, the hotter the coolant temp, and the cooler the cylinder temp. The oil is what does most of the mechanical parts cooling.

 

Heres a simple way to look at this ASE question. Mechanics will expect you to assume that since a car is designed with a thermostat, then IT SHOULD HAVE IT.

 

Yeah I figured that. If you've ever read some of these questions, they're very vague, even my instructor said so. :blah:

Yeah, if it came stock, it belongs there

 

I agree with the "if it's supposed to be there" But doesnt ASE also teach you how to repair things temporarily or in situations where normal fixes do not work. I agree that you should keep the tstat in there, ESPECIALLY during the summer because of how the system works. But I'm just saying in general, I thought they teach you bypass repairs, just in case.

 

I have read some of them. I took a few in the past. I admit, thats probably the main reason I failed a couple was because I wasn't keeping it simple, as in "If it's designed with it, it needs it". I'm taking them again in November. This time I aint gonna think so damn hard. LOL. Good luck with yours.

 

Shoulda used the main basic mechanic principle. K.I.S.S. "Keep it simple stupid."

 

Nah, they don't teach you how to "half-***" it At least where I'm attending.

Hey, you live about 15 minutes from me, I live in South Brunswick. You've probably seen my car at raceway park..check the sig

EDIT: I just checked your car out and realized something. I remember a while back seeing your car on cardomain and I said "Man, that car looks sweet.." I haven't seen it at the track though.

 

Technician A, Technician B, Technician 87Q Some of those questions are ridiculous. Good luck with your test though, this will be my first time taking a couple of them. I plan on passing all 8 someday, then passing the L1, and then the L2

 

I'm not sure if I've seen you're car, there used to be a Z around with my paintscheme/colors, but the stripes went down to the grill instead of stopping on the hood. You're interior is REALLY clean, I have problems keepingmine that clean, lol. As amazing as it sounds, I rarely go to the track, I have a number and everything, but I work nights a lot and have never realy gone to any of the weekend events. Also, the car hasnt really been running in like a year, but I just put a StealthRam on and should be ready to start up in a week or so, need to find some finishing touch parts. Thanks for the props. Your car is REALLY sweet too, get shinier wheels tho ;-)