it seems that the heater core in my 05 monte has a restriction, causing little to no heat output in the cabin. anyone think it's odd that the heater core would be clogged with this age of car, with only 50k miles? i'm crossing my fingers that a backflush will clear it up... i dont really want to have to pay for a new heater core (mostly dont want to pay for the labor!)

 

Its possible you have air in the system too...A complete coolant flush, and a system bleed should fix the problem if that what it is.

 

my 01 monte hada heating problems but i didnt touch the core i just changed the thermostat i that cleared it up what a nice cheap fix!

 

Might be the control, or something stuck in the door in the air duct. What is the temp on the gauge?

 

As mentioned, air in the coolant or a faulty thermostat can cause those same symptoms.

Other possibilities (but not as likely) would be:
improper mixture of antifreeze/water
radiator fan problem
bad coolant temp sensor
faulty HVAC control unit

 

All of the above could be your problem, but if it was me, I would start simple, and cheap. Based on the number of times people have had this problem, and the simple, easy fix being "bleed the system" I really think you probably just have air in the system.

Flush your entire cooling system, changing all the coolant. While your at it, replace the t-stat at the sametime. Then make sure you get all the air purged out of the system. This will more than likely fix the problem, and it is a good maintenance procedure too. So even if it doesnt fix your problem, you still didnt waste your money, because you should flush your coolant once in a while anyway!

 

I experienced a similar problem the other day. Check out the heater cabin post in this same forum. After all air was removed from my cooling system (after a pump replacement). The heater started working properly.

Do you notice a temp change when driving or accelerating? Do you hear a waterfall sound in the dashboard?

 

I have been experiencing similar problems with heating. I was hearing waterfall sounds (I described it like when you have a mostly empty bottle of water lying around in the car and the water is splashing around in the bottle). I could hear this sound frequently, mostly when I accelerated. After a while, the car would get warm and a minimal amount of heat would come out. Now I don't hear any noises and there is NO heat. I could pick up from your post, what do you think is causing the water sounds?

Thanks!

 

its air going threw your heater core it needs to be perged and flushed it is a simple fix. just take your time when you do it and make sure you have your heater turned on to make sure you feel heat coming in the cabin during the flush.

 

When I had this problem, I took it to the dealership expecting a simple fix. They ended up replacing the waterpump. This resolved the issue. They had to bleed it twice though. Original problem was due to no heat in idle position,, sound was present.