97 excort 190,000 miles

When the car has been running awhile the coolant reservior and radiator make a boiling sound. It really only does it when it's been at idle for a bit. Radiator is full. Fan doesn't seem to come on after it has been running awhile but does when you turn on air. At what temp should it come on? The temp gauge never goes above the middle point so it stays in normal range, even when the tank are radiator are gurgling.

Usually that exact combination of symptoms points to a blown head gasket. The only reason for there to be gurgling involved without overheating would be if exhaust was mixing in. You can get kits to test if there are exhaust gasses mixing in.

I guess the gasket could be bad but it's only 2 years old. This isn't a constant problem. It only does it every once in awhile.