low heat

[napew2009]

Hello. I just had a motor swap, and i barely have warm air in my 99 expy 5.4. the temp slowly climbs to half way, but barely any heat. i,ve replaced the thermostat twice in one day with no difference. How do i know if the water pump is any good in this one? By the way, there are no leaks. any suggestions i live in saskatoon, canada, very very cold right now.

 

[99 Expy]

If your water pump is bad, they usually will leak, and the motor should overheat. You might have air in your system which could cause your problem.

 

[napew2009]

What would be the fix to this problem? Thx for ur input.

 

[tmajikman]

You either need to burp your cooling system, take the cap off of the radiator, run the motor and let it run for a good 45 minutes with the heat on full blast, watch and see if the coolant goes down and keep filling it up, also could be a bad raditor cap or a clogged heater core.