[pdxRR]

I am going through this right now with my rig, its overheating and its 32F outside.

My theory is that you have a bad thermostat. Your leaking o-rings cause the cooling system to loose pressure, which lowers the boiling point of your coolant. Once you reach the flash point for boiling, the coolant expands and you get coolant coming out of the overflow and air in the system.

The thermostat is supposed to direct flow to your radiator once it heats up. If its not doing its job, you have no capacity for cooling the engine except what little amount the heater core can handle.

Q's: Have you noticed your heat being extremely hot? Have you noticed if your temp gauge reading is affected by what setting you have your heater on?

Also the accessory fans in the front only come on with the AC.

I would replace your thermostat Before you bypass the heater core. If it is a bad thermo, without the heater core, it will over ehat immediately.

This is just the theory i'm going on with my rig, still waiting for a new thermo to test it out.

 

[pdxRR]

I'm not exactly sure how you test the viscous fan. Supposedly there is oil or some fluid inside the fan bearings that stiffen when hot acting as a sort of clutch. I would presume that when the engine is hot, the fan is stiffer and more difficult to turn when the engine is off? Maybe search the forum, or perhaps someone more knowledgeable could chime in here.

I took my thermostat off yesterday, hoping that i may be able to remove the bits inside to open the flow up. What i ended up doing was stuffing some copper wire inside to hold that spring loaded diaphragm in the open position. I was able to twist the end of the wire around a stationary part of the thermostat inside, so as not to loose the wire inside the engine. I let the car idle for 30 mins and have been driving it today with no problems at all, it doesn't even get warm enough to reach 10:30 on the temp gauge. I figure this will hold me over until my new thermostat arrives tomorrow.