Guys I have a huge problem I cant figure out! I drive a 2002 wrx that has a stock engine. I was driving down the road and I found that my temperature gauge started to rise really fast!! So I drove slow home and installed a new thermostat, still didn't help. My symptoms are as follow: Overheating when driving down the road watching temperature gauge rise quick, when i rev my engine, it goes up fast! When the gauge is up close to red, my radiator is ice cold, however, it is very hott on the top of it. When the engine is not started but the key is on, both of my fans turn on and off and I hear a bunch of switches flip on. Could this be a temperature gauge milfunction, water pump, radiator, fan sensor or what. Any help is appreciated, my car is on jack stands and I dont have another car

 

Have you tried burping the coolant system? I've heard bubbles in there can cause the symptoms you are seeing.

 

or plugged radiator ??? top side is hot when it enters bottom ice cold? dont think its circulating

 

See if you can borrow one of those Laser? thermometers, the kind you point at a place and it gives you a reading. I've used them on motorcycle engines for overheat problems and it made trouble shooting much easier.

 

sounds like you have "vapor" lock. when you fill the radiator, you add cooland, start the car until it warms up, check fluid, add fluid until the system is full. You can assist this by "pumping" your top radiator hose. Caution: don't pump your hose to much!!!

 

make sure to use the subaru coolant conditioner as well. it helps protect against nasty build up in the block.