G
gussy
Guest
changed thermostat, cap and a couple of small by-pass hoses that blew. Water pump is ok. Engine will run cold and suddenly jump to hot and overheat. Heater core still blows cold. No white smoke out of exhaust. Would trapped air or blocked heater core cause this? Have not had the coolant sniffed for exhaust. Would blown gasket cause coolant not to get to heater core? Looking for possibilities before head gasket.