OK new info

Did a compression test just for the he'll of it... 160 across all 4 cylinders... So I'm good there.

Just did a pressure test.. Pressure stayed consistent at idle!
I held the idle at 4k for about 5 mins and hit the 2step twice then the pressure rose.... Once I let off the pressure dropped to regular temp in about a monute

 

No help?

 

How old is your thermostat?

 

sticky thermostat.

 

Still original thermostat

 

I'll definitely give that a shot

 

I had this same issue with my 92 Toyota Mr2 turbo, and it ended up being a blown head gasket. I know it's not the same motor but figured I'd let you know. Definitely diagnose a bit more first. I replaced my thermostat and radiator cap as well as flushing the fluids. It didn't fix my issue so I replaced the head gasket and everything was normal. Hope yours is less involved

If you have a shop near by, ask if anyone has a combustion leak tester that you can use. If your not familiar with it it'll sniff out exhaust fumes in your coolant. Should be something like this

http://www.amazon.com/gp/aw/d/B000NP...7lL&ref=plSrch

 

^This could be true. But if the coolant doesn't look contaminated I would replaced the thermostat first.

 

Going with the thermostat first.. Cheaper route then I'll go with more involved testing

 

new thermostat first is the top and bottom of the radiator hot .. if not could be blocked rad . then head gasket and you wont see contamination in the water if it's gone across cyl to water .

 

So I bought a thermostat and installed it.... I couldn't get an oem cap till Thursday so I bought a mishimotto one.

Installed and drove the car normal and drove it hard. No overheating at all... But with this mishimitto thermostat the car runs A LOT cooler..

Since stock opens at 80 and the mishimoto opens at 66.. Is it safe to run that cool? And should I assume my problem is solved?

P.s. I'm still buying an oem one

 

going to depend---your whole injection system, from open to closed loop is dependent on water temp--if it doesn't see the engine getting warm enough it wont switch over.. you may not notice it up front. But just so you know---you should have simply dropped the same temp thermos in it so you stop introducing new variables into your issue.

 

you will be fine. but, i would have gone with what your car is tuned with.

 

I bought an oem one today.... My car was all over the place and broke up a bit.... I wouldn't recommend the mishimoto thermostat to anyone that has been tuned on an oem one. Rpm was super high and fans only came on when at idle. Thanks for everyone's help!