odd problem that I need help with

[bikemenotyou]

I've owned a 1997 Subaru Legacy 2.5 GT for the past 4 years. I've kept up with the fixes that it has needed (timing belt, pullies, oil, etc), however it has been a bit of a trouble maker. most of it's problems have been due to electrical reasons. the last one was my alternator my battery was dying off and on and as soon as I replaced it I got more power then I had ever had with the car.
now I have a new problem that no one can figure out. I live in the mountains and usually when I drive up I can leave the car in fifth gear and easily reach 60-95mph without a problem. for some reason recently (4 weeks), the car is starting to over heat and I lose a ton of power.

heads are fine, brand new radiator, all fluids checked on a regular basis, and every auto shop is baffled. I want to say it's my cars computer but not sure yet.

anyone have any thoughts?

[evolutionmovement]

Probably head gasket causing the heat, which kicks it into limp home mode. Head gasket failures don't generally tell like they do in most cars and the 2.5 is known for head gasket problems.

[bikemenotyou]

heads have been replaced. when it does over heat I can push the clutch in and give the engine some gas and the temperature will go back to normal.

[evolutionmovement]

Does it overheat in light city traffic—constant changes of engine speed?

[bikemenotyou]

it only over heats with a hill involved. It will occasionally overheat on an offramp from the free way, and only after it has sat waiting for a green light. again I can give it gas and it's back to normal temps.

[evolutionmovement]

Are the fans coming on? Has the cooling system been bled properly and does it actually seem to be hot? It's possible hot air pockets in the upper jacket are causing false readings. It could also still be a head gasket in the earlier stages. Combustion gasses collect in the water pump pocket, leading to cavitation. Or at least that's the theory that matches the observed failure mode. Varying the speed of the impeller can dislodge the gases and restore coolant flow until the gases build up again. Eventually, there's too much gas and you don't get any coolant circulation no matter what.

[bikemenotyou]

the fans are rewired to be on whenever the car turns on. and yes it does seem to be hot, or at least it smells like it is. if it is the heads again how can I check them?

[ericem]

That's not good, when the fans are only it restricts air flow through the rad when driving. Why would you wire up the fans to work like this??