Drained my block and radiator today, went through the flush process but when i went to refill it only about 11 of 18 qts would go back in. Started it up to see if it would bleed itself and could get no warm air out of the heater. Checked all hoses, no air locks, now heat comes and goes. anyone ever had problems like this?

 

yes I had the same problem as you had, no flow to my heater core, it was an air lock, what i did was remove one of the heater hoses while the engine was running untill the coolant started running out, its sorta bleeding the system. one thing thats important to understand is coolant flow is pumped from the water pump into the bottom of the radiator, where the low pressure comes out from the top, into the top of the engine thru the thermostat, the heater core acts like the bypass flow when the thermostat is closed, another thing all new thermostats have a "open fail safe" this means when ur thermostat fails, it fails when its open, meaning full flow, so when ur thermostat is open the coolant flow will take the easy path thru that, and not thru ur heater hoses. I suggest that the thermostat be changed everytime the coolant is changed.

 

The system finally bled itself off after i drove it for a while with the resevoir cap off and then the heater started working properly and i was able to put more coolant in. Thanks for the reply.

 

'Bout a month ago I was changing the oil and noticed my coolant reservoir was empty. First time I'd seen that in the 6 years I've owned it. Figured I'd stop and get coolant first chance I get.
Next morning on the way to work I had the defroster on and when I stopped at a traffic light the heat stopped and discharge air went ice cold. I knew then it was really low on coolant.
it took 1.5 gallons to fill the system. Since then I have not had to add any more. I can't see any leaks or smell any anti-freeze.
If it was leaking I'd smell it. Ever since I had some go up my nose and into my mouth I have been able to smell it from a good distance. Unmistakeable scent.