95 Windstar coolant problems

I have a 95 Windstar that I recently changed the head gaskets on. I can't seem to get all of the air out of the cooling system. I run it and top it off several times over and it will sit in my driveway and idle for ever and no problems... soon as I put the cap on and take it for a ride, the temp spikes and no heat. (new cap and thermostat also) After bringing up the rpm's the coolant surges back and spills over losing significant amounts...or if i have the cap on it fills the resevior bottle and overflows that...ANY IDEAS???? Thank you

Hmmm. I'm surprised no responses, but this will put you back to the top of the stack.

Are your rad cooling fans coming on? So do you have inside heat, but as soon as you have a temp spike you loose it? Sounds like air still trapped in there. Did you install the thermastat with the tiny bleeder hole at it's top? I assume you installed it in the right direction? When running it with the cap off, can you look inside the rad and see fluid flowing inside it? Did you get oil in your coolant due to gasket/ head failure? If so, the radiator could be all gooed up and not able to provide adequate cooling. The best advice I've heard for the trapped air is to elevate the front of the van and orient it so that you can have the air percolate to a high point that you can open for it to escape and then you top off with coolant. I think the front heater core is high so it will trap air. If you have the rear heater, you could quite easily have a lot of trapped air following your repair. You may need to install one of those Prestone or like flushing Tees at a high point in the system ( heater or bypass hose) that you can connect a garden hose to get your air out. I'm not a big fan of them because they are plastic, and you are adding three more potential leak sources to your pressurized cooling system. Now this is just a hunch, but I'm trying to think of a surfactant that can be added to your cooling system that can help get rid of the air, kind of like Gas-ex. They make a coolant and water pump conditioner that might do the trick, but I'd have to research that more to be sure it would help.

Ok, thanks for the response...Yes I have great heat for about 5 minutes driving it and it loses heat and the temp gauge spikes. And yes, the cooling fans are coming on... As far as the thermostat installed with the little bleeder hole on top, I didn't realize that there was a hole in it. I guess I never paid that much attention to it. With the engine running the coolant circulates, but after running it for a while the upper radiator hose is hot and the bottom one is mildly warm. When it does circulate, it surges. It seems to sit still and then the water churns for a bit and then goes back motionless. I am completely at wit's end with this one. I've never had these kind of problems changing head gaskets on anything.

I still think your problems are caused by trapped air. It sounds like the fans, radiator, thermastat and temp sensor for the fans are all working. The water cycling on and off sounds possible and normal if it was cold outside. Though on mine, I didn't think the tstat would open and close once the engine was up to operating temp. It would stay open all the time once hot enough and then the fans would come on only when the coolant became hot enough for the ECT sensor to have the PCM to turn on and then off the fans. Mine would come on at 2200 ohms (wires off) measured at the ECT and 0.485 volts with wires connected to the ECT by backprobing the connector. Pulling the connector while the engine on will automatically turn on the fans as a safety precaution. To see if the pump is pumping through the upper radiator, you can squeeze it ( it should be somewhat firm), then goose the idle at the throttle and you should feel the hose expand, push open you hand some. When the engine is cold, before it's not enough for the tstat to open, the upper hose should be quite firm to hard. If not, you have air. I suspect air is still there the way you describe the surging when it moves through the hose when apparently the tsat opens. On my 95 van, the heater core hose that leaves the im next to the tstat is the highest point in the cooling system. I'd try to get air out there, or elevate the front of the van substatially to get the radiator opening the high point to let the air out. I'd be curious to know if trying the van with the tstat removed would improve the situation, not because of the tstat, but because of the air that may be trapped behind it.