Overheating help...

[FordMan1014]

Just flushed my whole coolant system because a oilcooler o-ring went bad. I got everything flushed out and put back together with all new gaskets and o-ring along with a new thermostat. Fired her up and went to get all of the air out of the system and it starts overheating. The radiator and hoses never got even warm. Does anybody know what the problem could be?

 

[mobilemech]

what brand of thermostat did you use? sounds like there is a vapor lock / air pocket in the motor and the thermostat is not opening

 

[FordMan1014]

motorcraft... that was my thought, that an air pocket built up right under the thermostat and wasnt popping it open. Is there any way to bleed it out?

 

[mobilemech]

take the heater hose off the the head, that will get most of the air out if it is trapped by the thermostat

 

[FordMan1014]

wont that just drain coolant and introduce more air into the system?

 

[mobilemech]

if the coolant is coming out of the head then an air pocket is not the problem. pinch off the heater hose then pull it off the head and see if there is any air, when its just coolant put the hose back on, by pinching off the heater hose you stop the core from draining and the intrussion of air

 

[typ4]

these engines dont airlock very easy, not like that foreign built crap.

 

[icanfixall]

What condition was your cooling system in before this issue. Might be some scale was cleaned out of the block and now its pluggin up the top of the radiator.

 

[hesutton]

Make sure you burp the block/heads by squeezing the upper radiator hose. If you just pour in coolant until there is fluid in the top tank of the rad and run it immediately, it'll spit back at ya.

Heath

 

[Agnem]

I would validate that your waterpump is running. If the hoses are not getting hot (especially the heater hose, as this is behind the thermostat and circulates water all the time), then I'd suspect your impeller has fallen off the water pump shaft. I've seen some Napa water pumps that looked like that could very well happen.

 

[RLDSL]

Just flushed my whole coolant system because a oilcooler o-ring went bad. I got everything flushed out and put back together with all new gaskets and o-ring along with a new thermostat. Fired her up and went to get all of the air out of the system and it starts overheating. The radiator and hoses never got even warm. Does anybody know what the problem could be?

Is your fan clutch locking your fan in early by any chance while the engine is still cool? This is a long shot, but when I first did my e fan conversion, my computer controller was turning the fans on too soon and was causing the thermostat to flutter shut from the cold water hitting it from the return. I'd have cold upper hose and rad and hot engine. A high flow thermostat got the coolant moving past the thermostat at a rate high enough to do some good to where it would actually stay open. It takes a lot to get them open but they slam shut in a heartbeat.