cooling system very, very pressurized?

[Black]

I bought a 93 Ranger 2.3, dirt cheap, not running with a broken timing belt. Replaced the timing belt and also the water pump while I was at it. Fired right up, seemed to run very nicely, but after idling for a few minutes began dumping lots of coolant out the radiator overflow . I'm thinking it's likely a blown head gasket, cracked head, etc, but thought I would check if there is some simple ranger 2.3 quirk I might have overlooked that could also cause this? Don't see any signs of coolant in the oil, so at least I've got that going for me. My compression tester is MIA or I would check that before tearing it all back apart.

 

[scotts90ranger]

there's probably air in the cooling system, these things can be persnickity about bleeding out the air, one thing you can do is loosen one of the clamps on the heater core. air in the cooling system can make the system very pressurized, in certain engines you can kill them because no coolant gets to the head and it doesn't heat the thermostat and will burn up the cam, etc.

 

[Wicked_Sludge]

have a shop pressure test the radiator cap and the cooling system. most shops will do it for free or a very small charge as it only takes a minute.