View Full Version : 2015 3 GT Heater Core
krash3
01-05-2018, 05:52 PM
Just curious to see if anyone is having longer than normal operation of the heater core in this beautiful -20 degree weather in southern Ontario?
For my car it takes 20-30 mins for the car to start blowing warm air. I'm talking warm for spring not warm for winter air. I don't have any leaks that I can find, so I think its weather related. Just need to confirm, thanks.
Flagrum_3
01-05-2018, 07:01 PM
I get warm air within a few minutes, hot within 8-10min.
What year is your car, you may need a thermostat.
_3
krash3
01-05-2018, 07:07 PM
2015
Flagrum_3
01-05-2018, 07:30 PM
Check your temp gauge, it'll read lower then normal if your thermostat is gone.
But first check your coolant level is up and proper mix.
_3
krash3
01-05-2018, 09:32 PM
Yeah, coolant level is at the full line. I checked it when I refilled the windshield washer tank. The car read only -17 when I left work at 4 pm. There is no temp gauge hanging outside of work though, so I don't have an accurate way to compare.
Flagrum_3
01-05-2018, 10:22 PM
Yeah, coolant level is at the full line. I checked it when I refilled the windshield washer tank. The car read only -17 when I left work at 4 pm. There is no temp gauge hanging outside of work though, so I don't have an accurate way to compare.
I was talking about your engine temp gauge, but just remembered you may not have one in your model. :/
If your heat doesn't build up in 20-30 minutes of driving, I would take it in and have her checked out, especially if your still under warranty. There's not many reasons for no heat or low heat. Ex; Heater core, thermostat or sensor. ...All should be covered under warranty.
_3
TheMAN
01-07-2018, 01:42 AM
if you have the defroster on, the A/C will be running... cooling the air some
krash3
01-10-2018, 10:43 PM
No, I don't run the AC in winter.
Clifford
01-11-2018, 10:46 PM
No, I don't run the AC in winter.
It runs its self when defrost is selected ,helps to dry the air to cut down on foggy windows, but it wont overpower the heat.
krash3
01-13-2018, 11:20 AM
Mine does not because I only run the heater. Never seen the AC icon on while I have just the heater going in any of my cars.
Flagrum_3
01-13-2018, 11:30 AM
Mine does not because I only run the heater. Never seen the AC icon on while I have just the heater going in any of my cars.
The AC light will not come on if you select any of the defrost modes, it explains so right in your manual.
Its truly dumbfounding how many people will buy a car and not take the short time to read through their car manual.
It would save alot of frustration....just saying.
_3
krash3
01-13-2018, 06:35 PM
I did, but from what I read, I can choose to have the AC on auto or manual. In manual the AC is totally off. I never have it on auto.
Besides, I posted this in regards to the original problem, the AC part went off topic.
krash3
01-13-2018, 06:36 PM
Don't assume things about people. You know what assume spells.
TheMAN
01-13-2018, 06:58 PM
how is it going off topic? You're saying your heater isn't blowing warm enough
one of the possible answers is that the A/C is running, and it DOES run if you selected the defroster mode... it WILL turn on the A/C whether you pressed the button or not, and it will run regardless if the display indicator or light is on or not... it will also automatically force the air to "fresh air" mode from the outside... you have no choice in both of this when you select defroster mode... it is programmed into the car's electronics... the car (and many cars for more than 10 years, already) was designed this way and Flagrum was merely reminding you that this is clearly stated in the owner's manual
with the A/C running, PLUS cold fresh outside air coming in, the heater air wouldn't be as warm as the incoming air to the heater core wouldn't be as warm
if I don't run defroster mode, I turn off the A/C and run recirculated air mode, the heater at full blast gets hot enough to knock my socks off on my 2016... but if I run the A/C and fresh air mode, the heater isn't quite as warm
you came here for help, we're all trying to help... it really would help if you slowed down to read and think about what people are saying before knee jerking to defence
Clifford
01-14-2018, 12:12 AM
You need to have the thermostat checked, sounds like it is not functioning correctly.
Flagrum_3
01-14-2018, 01:16 AM
I did, but from what I read, I can choose to have the AC on auto or manual. In manual the AC is totally off. I never have it on auto.
Besides, I posted this in regards to the original problem, the AC part went off topic.
krash3
I haven't read the 2015 manual since I own an '05, so I figured that the system would work the same and if you have read your manual, I apologize but maybe read it again on this particular issue. If you have your system off "Auto" and in manual mode, it should work the same as mine. Meaning if you select any defrost mode your AC turns on automatically and no indication is given that it is on. Except you may possibly hear the compressor switching on and off.
Anyways, all that aside. Today I started my car cold and threw it on one of the defrost modes (Windshield/Floor), just to compare, and with heat dial turned high. Within 8 minutes tops I had hot air coming through. So again as I mentioned much earlier I think you have a possible thermostat related issue, as its unlikely your heater core would be an issue so early.
So my suggestion is to take it in to the dealer and have it checked out. Especially if your still under warranty, without hesitation.
_3
stock3
02-09-2018, 11:50 AM
At pretty much at any temp below freezing, the AC compressor will not engage when cold started. It may engage once the vehicle is fully warmed up and the engine bay temp rises, like in traffic. But at -20C, the AC will not engage at all, so no point even discussing it.
If the coolant level is fine, thermostat may be suspect, but the car should throw a CEL for that. Mine did way before I could notice any heater issues.
There is another possibility, the blend door is not operating properly. Blend door is what brings in the cold outside air into the cabin, but if you want heat, it will also mix it with the hot air coming out of the heater core,
Powered by vBulletin® Copyright © 2026 vBulletin Solutions, Inc. All rights reserved.