Seems like a lot of people have had this problem. Is this a common issue on Evo, since people with 44k miles have this problem? Jw because I don't have one yet, but I'm thinking of purchasing my friends Evo when he buys a new car hopefully by end of this year/early next year.

 

It's not common. I had the stock unit for over 65K miles. I burned up a piston when meth failed and that unit went into a friend's Evo while I was rebuilding. I am sure it's still around somewhere. As long as your engine doesn't overheat it should last for a good while.

 

Thanks for all of the feedback thus far everyone

Im still not entirely convinced its my thermostat however. The car has no problems warming up when cold which it probably would if it were stuck open.

Is it possible that its not stuck open but "sticks" at times?

I read in some other threads a way to test if its functioning by putting it in boiling water to see if it opens. Could someone explain this a little more in depth or is it really that simple?

Also, is there a chance that I installed it wrong? It seemed quite straight forward so I am wondering if I missed a crucial step, flipped it 180 degrees out or something.

Thanks again for all of your help.

 

put a new oem stat in it

 

I did before and it didnt change anything. Maybe the one I got was faulty? Whats the best way to test mine, because although they are cheap <$30, I dont want to throw money at it if its not actually the problem...

 

Could be still your t-stat as u said it cools down your gauge on the highway.. Might be halfway open and your coolant continously goes through your block.. Hence the air that goes through the rad. Also, make sure the little thing from the t-stat is in top part.. I forgot what its called.. Lol

 

Halfway open is interesting, that could definitely be it. I figured it was either open or closed.

Is this the thing you are referring to? If so I believe I put that in the front.

 

 

^Thanks for the video. How would I know then if its staying halfway open?

My guess would be that I boil it to see if it opens which it probably will and then take it off the heat and watch how it responds to the temperature change. Assuming its not good, itll stay open or close a little but not completely. Does this sound like how it should be tested?

 

So I pulled out the old one and tested it in boiling water. It appears to be functioning properly as in it opens and when removed from the water slowly closes. I have no idea if its not fully shutting or closing too slowly so I decided to order a new one which will be here tomorrow.

Assuming the thermostat was fine maybe I had it clocked improperly. Can someone tell me where that bleeder valve should be positioned? I believe when looking at the engine it should be at 12 o'clock essentially on the exact opposite side of the where the upper radiator hose connects. Is this correct or should it be on the side right by the neck of the upper radiator hose?

 

Start out with cold or lukewarm water. Insert the thermostat and a cooking thermometer. The OEM thermostat should start opening at around 176 degrees. Cold running usually means the thermostat is opening early (a problem I had). Continue heating until the thermostat is fully open - probably no need to boil the water. Remove the pan from heat and watch to see that the thermostat closes at 176 degrees. The operation of the stat should be smooth - it shouldn't stick and jerk.

I don't think the positioning of the dingle valve is important. Just don't install the thermostat upside down.

 

I appreciate the info. I dont have a digital thermometer or IR gun unfortunately so i guess my water test was essentially useless because I dont know exactly when it was opening. I did notice that it would stick a little before it was fully closed but Im not sure if that was just due to the tightness of the rubber gasket and at the sticking point it appeared to be sealed but not completely seated.

Nonetheless I have ordered another new thermostat which ill get tomorrow and pop in.

Just to be sure, does it go in short side up and the longer side with the spring down?

 

spring side down small bleed valve to the back

 

Thanks, that's exactly how I had mine in there before. Ill let you know how things work out after I get the replacement in there tomorrow!

 

have you a pic of the old stat ???