2001 Tahoe Weak Heat

[Bedore]

Greetings all,

Recently acquired a 2001 Chevrolet Tahoe. The nights are still cold here and I noticed the heater is not working correctly. The blower motor works on all 5 settings, and the air will go from hot to cold. But when on hot and full blast the heat coming out of the vents is lukewarm. Revving the motor some will increase the temperature some but not much.

I took it in and had the cooling system flushed. Still have warm/little heat. Where can I check next?

 

[Gordy]

Greetings all,

Recently acquired a 2001 Chevrolet Tahoe. The nights are still cold here and I noticed the heater is not working correctly. The blower motor works on all 5 settings, and the air will go from hot to cold. But when on hot and full blast the heat coming out of the vents is lukewarm. Revving the motor some will increase the temperature some but not much.

I took it in and had the cooling system flushed. Still have warm/little heat. Where can I check next?

It could be a blender door not fully functioning seen that happen. Can you here the vane moving when switching temp dial from hot to cold?

Other wise plan on a new heater core. I had to install one on my 01. When you see it you will understand how they plug. Very small passage ways in the HX.


I hired mine done. You gotta rip the whole dash out to replace. Heater core was 70 bucks labor was 600 bucks. Glad they did it because thay put it all back together and the new one had a bad tube on the heater core that leaked, Had to pull it out, and get another one defective unit.

 

[Bedore]

It could be a blender door not fully functioning seen that happen. Can you here the vane moving when switching temp dial from hot to cold?

Other wise plan on a new heater core. I had to install one on my 01. When you see it you will understand how they plug. Very small passage ways in the HX.


I hired mine done. You gotta rip the whole dash out to replace. Heater core was 70 bucks labor was 600 bucks. Glad they did it because thay put it all back together and the new one had a bad tube on the heater core that leaked, Had to pull it out, and get another one defective unit.

Thanks for taking the time to respond and help me out. To answer your question, when I rotate the temp wheel from cold to hot, I can head an electrical motor running for approx. 9-10 seconds. After which I can hear it butt up, or stop abruptly. Does that mean the door is operating correctly?

If so, then it would be the heater core...yes? And if so, can it be back flushed and cleared or is that too late?

 

[Gordy]

Thanks for taking the time to respond and help me out. To answer your question, when I rotate the temp wheel from cold to hot, I can head an electrical motor running for approx. 9-10 seconds. After which I can hear it butt up, or stop abruptly. Does that mean the door is operating correctly?

If so, then it would be the heater core...yes? And if so, can it be back flushed and cleared or is that too late?

Sounds like the mixing vane is operating correctly.


We tried back flushing, and it worked in the shop, but did not last 2 days before doing the same thing again. You can try it, and if its not to scaled up it may last a while. But its avoiding the inevitable. The heater core has small passage ways that scale, and plug easily. If I had known this I would have been a little more prudent about radiator flush intervals. I have had them leak in past vehicles never plug. The rear heater core is still fine.

 

[Bedore]

Sounds like the mixing vane is operating correctly.


We tried back flushing, and it worked in the shop, but did not last 2 days before doing the same thing again. You can try it, and if its not to scaled up it may last a while. But its avoiding the inevitable. The heater core has small passage ways that scale, and plug easily. If I had known this I would have been a little more prudent about radiator flush intervals. I have had them leak in past vehicles never plug. The rear heater core is still fine.

Thanks again for the response. I am having it back flushed today. If that works, I will be closely monitoring how well it works over the next few days. But I do agree at some point it will probably be best just to replace it. Thanks again for the help.

 

[07Burb]

Sounds like a heater core issue.

With that said, have you paid attention to your temp gauge on your dash? The reason I ask is that it could be a tstat issue if it's not allowing the motor to get up to full operating temperatures and therefore shoot out warm air as desired.

 

[Bedore]

Sounds like a heater core issue.

With that said, have you paid attention to your temp gauge on your dash? The reason I ask is that it could be a tstat issue if it's not allowing the motor to get up to full operating temperatures and therefore shoot out warm air as desired.

Thanks for taking the time to reply. At first my thought was low coolant. When that was not the issue, I scheduled to have the cooling system flushed and a new t-stat installed, which was done yesterday. I always watch my gauges like a hawk, and it's never gone above 200ish or so (it rarely moves past the line or two before 210). I know a bad t-stat can cause the engine to overheat, or never get to temperature, but in this case it sure appears like the heater core is the culprit. If the back flush does not work, I will have to have it replaced.

 

[07Burb]

looks like you're well on your way to getting it resolved without my input

 

[Bedore]

looks like you're well on your way to getting it resolved without my input

No worries, any help/input at all is better than none. I understand and often times people overlook simple things. It's good to have constant reminders.

 

[John__M]

My 2000 Yukon does the exact same thing. ENgine comes up to temp, tstat is fine, but low heat from the heater.

I back flushed it last year, not much of an improvement. I guess I will live with it. Major PITA to replace.