Originally Posted by '93TurboD

Maybe a plugged hose or you could have a head gasket leak developing. Take your car to a shop that has a gas analyzer. Run the car with the rad cap off and bring it up to temperature (when your T-stat opens). Place the probe @ the rad filler and check the HC (hydrocarbon) reading. If there's a higer than ambient HC reading your head gasket is pooched.