Its been pretty cool here the last few days (like -30) and it seems like my heater is blowing luke warm air at best. The engine seems to get up to temp easily enough but the air coming out of the vents is not very warm. I've heard that the door on the heater core its self can sometime not open very wide, does this sound like a reasonable assumption? If so, how do you fix it? Any help would be appreciated

Cheers
Kev

 

Eventhough engine is up to temp first question is hot water getting to heater core and second is it coming out hot. If one heater hose is hot and the other one isn't you might have a pluged core. Luke warm could also mean that the thermostat is stuck not letting hot water to the core. The blend door would change direction when you change from floor to vent to defrost if it is luke warm on all three setings I would check your stat and core before the blend door.

 

Ya it is warm enough to defrost the windows and make it somewhat comfortable in the cab, but its not getting blowing as warm as it should

By the thermostat, do you mean the main thermostat or is there one just for the core?

 

Check you blend door to see if it is closed or open all the way to allow air to pass over the core. my truck did the same thing and that was the cause. i see in your signature that you have a 86 944. i had the turbo version and it was a blast! but sold it cause it was two kids and that car didnt work

 

My first question is if the engine gets up to operating temperature (eg Look at the temp gauge). "Seems to be" is not an accurate answer. If it is not, then the thermostat has failed in the Open position. No matter what, you'll never get warm air unless the thermostat is replaced.

 

Ya I have a NA (very slowwww) one, its a blast to drive though

Where under the dash is the heater core, passenger side? I will have to take a look around down there today to see if anything looks disconnected.
How do I check if the blend door is working correctly?

 

Assuming the gauge is working correctly it is getting up to temp, thats why I am asking about the heater core

 

Before going through a lot of the motions everyone also prescribed, try back flushing the heater core. There's another post here where someone was experiencing poor heat. He disconnected the core, back flushed it and ended up pumping a lot of crud out of said core. Once reconnected, gets phenomenal heat.

 

How do you do that? Just hook a hose to the outlet on the core?

 

i am having the same problem with my truck...mine is getting up to the correct temp....knowing that how do i get to the heater core door? or should i try to backtrack the heater core?