Coolant System Expert?
 

So I need some ideas as to what problem I'm having. This doesn't have to do with my mustang, it has to do with my volvo but I figured the cooling system is basically the same from car to car. I have replaced the waterpump and thermostat on my 86 volvo 740. There does not appear to be any leaks. The return hose from the thermostat housing gets warm/hot and the waterpump hose gets warm. The system also appears to be getting pressurized. The heater blows cold and the car slowly creeps up in temperature until I wont let it get any hotter and kill the car. What issue could I be having? Should I check the thermostat? The radiator doesn't look original and it looks fairly new. Could it need a system flush? Any ideas as to what it could be would be appreciated.

As an aside I removed the cracked fan shroud until I have time to get another one. Do those things make that big of a difference as far as drawing air into the radiator?

Is the fan operating correctly? Have your burped the system?

I guess the thermostat wasn't open. Shut it off and let it cool down. Ran the car with the cap off and it started sucking more coolant and filled it up more. I guess it was low on coolant. But now the damn thing is missing. I guess it got too hot when the first remanufactured waterpump failed after 15 minutes.

uh oh, hopefully no major problems. I was about to say though the most common problems after doing a flush is air in the system.

Exactly. Rad cap off burped the system.

Fixed the coolant system and found the misfire problem. One of the plugs on an injector decided to back out. Secured it tightly and the misfire disappeared.

Sounds like an air bubblein cooling system not letting coolant flow through heater core

In the future, is it best to continue filling the expansion tank after the thermostat has opened?

I usually leave the cap off the Rad until the Thermostat opens and pour into the spout. afterwards fill the reserv.