How to Test Your Thermostat

[Lextreme II]

I got this thermostat at home and would like to test it out before installing in my car.

Picture 1: Is a normal length of the spring fully expanded. Full expansion is closing radiator fluid from entering the block.

Picture 2: I am placing the thermostat into a small pot to boil.

Picture 3: The Thermostat is ready to be boil

Picture 5: The thermostat's spring contract and open up the valve

Picture 6: You can compare the spring length between picture number 6 and number 1.

If your thermostat open during boiling, its most likely is good. However, its not ALWAYS the case. When you take your car to a mechanic complainting overheating. This is the first thing they would replace without testing it.

 

[Zuffen]

Does your wife know you've been cooking a thermosat on her stove?

I hope you cleaned that mess up you made under the pot?

 

[Pro]

i can;t wait for the post from someone saying to remove the thermostat altogether coz it's just a restriction....LOL

 

[Lextreme II]

I had it out for a while but i was reading somewhere in the manual stating something about the thermostat might affect idle. So i put it back. I hope my wife won't find out about this. I was doing this while she was at work.

 

[Pro]

you should never run a vehicle without a thermostat.

it basically keep pressure int he cooling system, "holding" the water against the metal in the engine.

think about this for a bit - a hot bbq plate. pour your beer on the sausages and watch it bead off in droplets.

now put a wet rag on the hotplate. i'll bet the beer didn;t cool the plate at all, but you can;t cook the sausages on the plate where the rag was because all the heat is gone.

that's because the pressure of the wet rag held the water against the metal to cool it - just like a thermostat.

without a thermostat - the coolant can bubble and almost boil. this creates air pocket - and air in the cooling system = corrosion.

 

[jibby]

That's funny I need a new thermostate as my car is running too cold with the fans, believe it or not. At idle I stalled out once today... Never happen before.....

Ps - Are you serving dessert with that thermostat?

 

[cribbj]

Coolant thermostats serve to keep the deltaT across an engine at a nominal level, plus give the coolant some retention time in the radiator to let the air/coolant heat exchange happen.

Although engines need "some" deltaT in order to reject heat from the coolant, they don't like a lot of it, particularly when there's mixed metallurgy involved. Picture what happens when a cast iron block is sucking in coolant at 50 degrees C, and the aluminum head is spitting it out at 100 to 110 C. Different metals with different rates of expansion start breaking loose from each other, and their sealing surfaces do too. Ask anyone who owned an early iron/aluminum engine.

Industrial engine designers try to limit the deltaT across a motor to 20 degrees or less, and that's what the 'stat is there for.

John

 

[jibby]

Question if you remove the thermostat will you make horse power gains.......(just kidding).:burnout: I agree the thremostat is an important item in the car and should not be removed. That is why every car that is sold from factory is equiped with one, they do serve a purpose.

Now do any of you what is the best temperature thermostat to get for the IUZ...'s? Is the stock OEM's the best thermostat to use in our cars? Need to shop one out tomarrow...

 

[Lextreme II]

There are different temperatura rating. I think the TRD Thermostat is little lower and which means it will open earlier.