Hi,

My 04 Tribute 3.0L only seems to blow luke warm air after it's been running for awhile (10-15 min). It never seems to get completely hot. The coolant is full and was drained/replaced earlier this year (Feb). The thermostat was changed when the coolant was replaced. Does anyone know what might be going on here? The Mazda dealer locally said that he's heard complaints on this before when the weather is really cold. Thanks in advance for any advice.

 

Is the car even getting up to operating temp?

 

Yes, the it is running fine temp wise...no over heating. Temp comes up to where it should as normal.

 

I am not 100% sure but there SHOULD be a valve in the heater lines that turn off (or restrict) the flow of coolant into the heater core, if that is not opening all the way that could be your problem.

 

A few things, check the heater hoses my '02 has them low center from the engine into the firewall to the core, one should be to operating temp with engine at operating temp. The other should be not as warm, you should feel water/coolent flowing through both with the engine temp up, and thermostat open. If so, I'd suspect blend door is allowing outside air into the system. Is the heat set to full red, and the heat seat to heat? Is there anything blowing out of the defrost?

 

here is an interesting twist....

just flushed my heater core and seem to be getting a little more heat but,...

couple of comments. on the return (I think) line from the heater core it branches off at a "T" and a smaller line goes through the throttle body then rejoins the main return line to the oil heater then on to the water pump. WHAT ARE THESE "T's" AND COULD THEY BE RESTRICTING FLOW???? some sort of throttle body preheat for incoming air?

I may have a thermostat issue, it is so cold right now it is not opening. At least the lower hose going into the thermostat housing is cold. the car temp guage is reading in the normal range. I guess i have never seen a thermostat not open because it is so cold outside (below 0F) . Either that or it is sticking.

However a sticking closed thermostat should not cause a low heat condition I don't think. the pump should circulate water through the core even if the thermostat is closed.

Anyway I have a low heat condition too. Also an interesting part of my problem is at idle the heat air temp decreases but when I start driving or even rev the throttle the heat temp increases. HMMMMMM. any ideas?

Ice

 

BTW mine is a 2005 V6

Ice

 

Mine turned out to be the heater core...guess it just needed a good flush. She seems to be blowing nice, hot air again.

 

The flush seems to have done the trick. My daughter is not complaining anymore. I used ice machine cleaner and let it sit for about ten minutes. then blew it out and flushed with clean water a couple of times. Ice

 

mines doing same thing what did you do to resolve the problem