So my 05 STi has been down for 2 years. I sold everything under the hood so I needed a whole swap to get it running again. I bought a full engine swap from a 04 STi with 71k and dropped it in. When filling the radiator coolant it started leaking through the block so I ended up changing the water pump, timing belt, tensioners etc...I used a Gates OEM timing belt and water pump kit. Oh when I took out the water pump I noticed the blades were rubbing against the block? Anyways I drove the car around for a couple days with no problems. The next day I needed to drive from L.A. to S.F. and about half way (3 hours) I noticed on my Defi gauges the water temperature rose to 220* so I pulled over to let it cool. After that I drove the rest of the way (3 hours) with the heat full blast and it didnt go over 190*, but when I got off the freeway it started to over heat again! It went up to 230-235* this time around! The only thing I thought of was the thermostat being bad. I changed the thermostat with an OEM one and it still over heats after 30 minutes from a cold start. The idle starts to go all crazy too when this happens. Everything else seems perfectly fine. Any thoughts? Thanks in advance for any help.

 

anyone please?

 

could be as simple as airlock and you need to burp it out really well. Could be a bunk thermo. You drove on it a long time. You might have cooked it which will require machine work to true it out again.

 

i burped it twice. once when i put the new thermostat in and once 15mins later. the new thermostat only has 30mins driving on it...sorry when u say "cooked it" what are u referring to?

 

i just mean if you drove on it while it was hot, or if it reached a high temp, it could be warped. Temperature abuse is a futher mucker.

 

I was going to say air bubble bleed it on an incline but thats been covered. Try running it with out the thermostat see if it over heats then

 

Did you flush the radiator?

 

are both radiator hoses hot when you over heat?
do they both have pressure?

 

like the block can be owned?

 

ive change the fluid 3 times but i didn't use pressure to flush it out. i just emptied it and but new fluid.

 

i believe so but i can double check. if they are? and if not?