Pontiac G6 Heating/Cooling

howardpmhowardpm Member Posts: 28
edited April 2014 in Pontiac
So I'm a bit confused how the AC in the G6 works.

I turn on my car with both knobs on auto and the Air Conditioning light goes on. Now as far as I know most people aren't turning on the AC in the winter, also you tend to get worse gas mileage with this on. So I always turn it off.

Now it says in the manual the air conditioning compressor runs when the outside temperature is over at 40 degree F. Why would I want the AC on when its 40, maybe if its 80 or higher.

It also states when the air conditioning is selected or in AUTO mode, the system runs the air conditioning automatically to cool and dehumidify the air entering the vehicle, Again, if its cold outside why would anyone want the AC on it.


  • mschianog6mschianog6 Member Posts: 2
    Hey all,

    I got my 2008 G6 at the end of January. Being that the weather has started to be warm, I've been using my a/c the last two-three weeks. However, the air is never cold.

    I decided to bring my car in to have it checked out last Monday. They said they couldn't find anything wrong, but they would recharged the a/c for me. When I picked up the car the morning after and turned on the a/c, it was slightly colder -- but still not cold enough.

    I have a 45 minute commute to and from work, so I've had ample amount of time to test the air conditioning out. I tried several methods -- recycled air, incoming air, flushing the hot air out of the car and then turning it on, etc. Nothing really works. When I'm using incoming air, the air is slightly colder -- but it's more of a "cool" than a "cold." And when I'm using recycled air, it's just flat out warm. I've tried everything during my 45 min commutes. Nothing improves it.

    I had a Civic sedan before this and I remember the A/C getting so cold I would have to turn it off. I wish this was the case for my G6, but it never gets cold enough. It's roughly 75 degrees outside; I can't imagine what it's going to be like once it's 90 degrees out.

    Are there issues with our G6s that I am unaware of?
  • mschianog6mschianog6 Member Posts: 2
  • busirisbusiris Member Posts: 3,490
    This should be a simple issue to either prove or disprove, and here's how...

    On a warm day (70 +F), turn on the A/C and place a thermometer immediately in front of one of the air outlets. Cold air coming out (in the neighborhood of 45 F)?

    If no, you have a problem with the compressor, condenser, evaporator or duct work. Take it to the dealer and reproduce the test in front of a service representative.

    If yes, the system is operating nominally.

    Still, I don't know why they would add Freon to the system unless it was below specs. On a 2008 model, it begs the question....why is it low?

    Makes me wonder about the quality of service that your dealer is able/willing to provide...
  • howardpmhowardpm Member Posts: 28
    Anytime the AC light is lit on my 2008 G6 I have a really gross smell from the vents. The dealer said this is normal and I find that hard to believe, it only happens when the AC is on, when its off everything is good.
  • bvdj84bvdj84 Member Posts: 1,724
    Wow! How is that normal? Uh, I have an 08 G6, and I have no gross smells. Why would they not want help you out, since GM would be the one having to fund the solution for it. I would recommend you calling GMAC and filing a report, perhaps using another nearby dealer that might work with you. You would be suprised at when I went to one dealer, they were less than helpful, and then went to another dealer and they treated me so well! Somebody is not doing their job. Weird smells coming from the vents is NOT normal...lol WOW! I think dealers have used every line in the book, but if you want to buy a car, well their on it, but once you buy it, drive it off the lots, its your problem...

    Anyhow, do that, Good Luck!
  • Karen_SKaren_S Member Posts: 5,092
    I've seen this complaint with several make/models. A lot of the times it is due to a plugged drain. The moisture builds up, mixes with bacteria, and you end up with a funky mold growing in the system. I'd take it to another dealer for a second opinion.
  • onanislandonanisland Member Posts: 2
    My 2007 G6 GTs have a flatulence dispersal system, aka top down. We can't help it if you don't have the good sense to keep the top down. Blaming it on the AC is a neat ploy, though. ;-)


    P.S. A girl I knew 54 years ago liked my white one a lot. She got one in granite for a wedding present, proving the car is a really, really good chick magnet. Happy days are here!
  • belaircarguybelaircarguy Member Posts: 107
    I am not sure if the G6 has a "cabin" air filter or not. I had the same problem a number of years ago with an Olds Silhouette minivan. After the car was 2-3 years old, I had the same problem. I looked in the owners manual, and found out there was a cabin air filter. It was inside the glove box, but that location can vary from car to car. I opened the case for the filter, and needless to say the filter was quite dirty. I went to an auto supply shop and purchase a new filter ($15). Changed the filter and presto - no more smells.

    I have now learned to check for a cabin filter on every car I own. I change them once per year, generally at the start of the air conditioning season. No more smells in any car. You would be surprised by the amount of dirt on these things after one year.

    I also have noticed that while many owners manuals show there is a cabin air filter, in almost every case or car, there is no recommendation to change it.

    Hope this may solve your problem

  • gtp2gtp2 Member Posts: 1
    I had this problem with an 08 Grand Prix at about 15,000 miles. It started off with everytime I turned on the air conditioning, a moist, moldy smell would emanate from the vents, until it began happenening even with outside air coming in unless the heat was on. I called the dealer and they stated I needed to replace the cabin air filter for a cost of $30 to eliminate the problem. A few days later when I took the car in for the scheduled service, a technician and service manager turned the air conditioner on full blast and stated they didn't smell anything and that the odor coming from the air conditioner was normal on every car, regardless of the fact a terrible pungent odor was coming into the cabin.

    I told them I wanted to replace the air filter regardless, and they then stated their was a $100 labor fee plus the $30 part. I told the service manager there is an obvious unusual smell coming from the air filter and if he doesn't replace the air filter for the promised cost, I would call my attorney. The service manager then told me to call whoever I wanted to. My attorney wrote them a certified letter describing the promised price and the health risks that create associated liabilities, and a week later the General Service Manager called me back and sheepishly apologized and told me they would fix whatever needed to be fixed with no cost to me.

    When I took the car in, they provided a loaner, shampooed and pressure cleaned the vent system and replaced the cabin air filter. The service manager said it happens every now and then but it's unusual for it to happen at 15,000 miles. On the service receipt it said mold was in fact present in the vent system and the cost would have slight been over $200. I suggest you have them look at your issue closer.
  • catkccatkc Member Posts: 10
    The first year I had my convertible I noticed the bad smell. I took some antibacteria spray and sprayed it down the vents several times and it seems to have taken care of the issue in my vehicle (2007 G6 Convertible)
  • randy66randy66 Member Posts: 1
    i love my g6 except for that SMELL! I thought it was me at first!!! my girlfriend also smells it so i know it is there. I am going to the dealer I purchased from last february,altho they took 6 months to get me a new rim (noticed day after i bougt it front end shimmy also had to replace a part for one of the wings) if I do not get results from them i hope the pontiac dealer will help me. it is not very pleasant to have to smell mold soooo top downwhen i can western ny does not let that happen often
  • pennie3373pennie3373 Member Posts: 2
    I have a rotten egg smell that comes from the heater being turned on.
  • maddog0324maddog0324 Member Posts: 55
    So your windows won't fog up.
  • kimchanellkimchanell Member Posts: 3
    I have the same smell, it smells horrible.
  • maddog0324maddog0324 Member Posts: 55
    I had this problem with my 2008 G6. I did some research and found that there is a feature that runs the HVAC blower for a couple of minutes after the a/c has been running and the vehicle has been turned off. The feature called "Afterblow" is available from the factory, but must be enabled at the dealer. I had it enabled in May and have not experienced the musty smell since.
  • barefoot63barefoot63 Member Posts: 3
    I have a 2005 G6. I was just told that it will cost me in the neighborhood of $600.00 to repair my heating. Seriously?...the car is only 6yrs old! Why did the heating system seem to fall apart?
    The fan is working fine...high to low....floor to defrost, but no heat. Is there any recall on this problem?
  • gmcustsvcgmcustsvc Member Posts: 4,252

    I apologize for the problems you are experiencing. Are you currently working with a GM dealership or an independent shop? I would be happy to see if your vehicle has a recall, please email me your VIN.

    You can get my email by clicking on gmcustsvc.

    Thank you,
    Caron, GM Customer Service
  • barefoot63barefoot63 Member Posts: 3
    Here is my VIN: 1G2ZG528154168365
  • barefoot63barefoot63 Member Posts: 3
    Sorry to not answer the question....I was at an independent shop that had recently fixed my ball bearings for me. I trust in what they say but don't have the money to fix my heat and was looking for a free help guide so I could try to fix it myself.
  • maddog0324maddog0324 Member Posts: 55

    I had this problem with my 2008 G6. I did some research and found that there is a feature that runs the HVAC blower for a couple of minutes after the a/c has been running and the vehicle has then been turned off. The feature is called "Afterblow". It was installed at the factory as inactive and must be enabled at the dealer. I had it enabled on my 2008 G6 in May (cost $50) and have not experienced the musty smell since. GM had issued Technical Service Bulletin #99-01-39-004B that lists enabling Afterblow as a solution to the musty odor complaints. I hope this helps.

  • gmcustsvcgmcustsvc Member Posts: 4,252
    I would also recommend contacting your local dealer again for more assistance. If you are having problems finding resolution, I would recommend contacting Christina by email. She should be able to look into this further. Thank you in advance.

    Tricia, GM Customer Service.
  • howardpmhowardpm Member Posts: 28
  • msikor01msikor01 Member Posts: 3
    2008 Pontiac G6 GT Convertible w/3.5L
    Occaisionally, after driving the car with the AC on, and working, you make a stop for 10-15 minutes, and when you start the car, the AC will not come on for quite a while. It seems to be more prevalent on hotter days, 85+.
    Dealer has checked it out twice and cannot find the problem.
    I do know that when there is no AC, the compressor is not engaging.
  • gmcustsvcsarahgmcustsvcsarah Member Posts: 1,964
    I'm sorry to hear about this elusive problem with your G6's air conditioning. Has your dealership ever been able to duplicate the situation you're describing, or is the event too intermittent to be predictable?

    GM Customer Service
  • msikor01msikor01 Member Posts: 3
    It was replicated during one service call, however, the repair performed (system pressure check) did not correct the issue. The last time we had it in, the weather cooled off and the failure could not be duplicated. It is going in for service on 7/18. The temperature is forecast to be in the mid 90s, so that should help.
  • gmcustsvcsarahgmcustsvcsarah Member Posts: 1,964
    I hope that everything goes well for you tomorrow and am looking forward to hearing any updates.

    GM Customer Service
  • carlos42carlos42 Member Posts: 1
    hi, i have same problem in my car . you find a solution for this problem?
    Please let me know, i buy car for my daughter and have same problem
  • msikor01msikor01 Member Posts: 3
  • gmcustsvcsarahgmcustsvcsarah Member Posts: 1,964
    Sorry to hear that you have the same issues, carlos42! Hopefully msikor01 will update us on what her dealership found. Were you planning on getting this looked into or not yet?
    Sarah, GM Customer Service
  • jessicajanejessicajane Member Posts: 1
    For a while I've noticed a puddle under my car, I always assumed it was the a/c no big deal. Recently it has started to get colder and I've started using my heat, everytime I turn it on for the first time like overnight, it stinks. Smells kinda like vinegar. Now when I turn the heat on it smells like its burning and I'm hearing a terrible squeak from the front passenger side of the car. Any answers?
  • gmcustsvcgmcustsvc Member Posts: 4,252
    Hi jessicajane,

    We are sorry if you are experiencing a weird smell in your vehicle. I see that you are seeking answers here on the forum for this concern. If you decide to visit a dealership for this issue please let us know, as we'd like to stay involved if a repair is needed. Please keep us posted on the status of your vehicle.


    Amber N.
    GM Customer Care
  • beachinit46beachinit46 Member Posts: 2

    i found this forum while doing a search for the same issue, horrible horrible smell when the a/c or heat comes on and for a few minnutes when you turn it off. also noticing a moisture issue, the windows always fog, so has anyone ever found a solution to this? my car also is an 08 G6. seems like this problem goes all the way back to 08

  • ray80ray80 Member Posts: 1,655

    @beachinit46 said:
    i found this forum while doing a search for the same issue, horrible horrible smell when the a/c or heat comes on and for a few minnutes when you turn it off. also noticing a moisture issue, the windows always fog, so has anyone ever found a solution to this? my car also is an 08 G6. seems like this problem goes all the way back to 08

    First thing I always suggest is to check cabin filter if so equipped. Many times 'stuff' growing (or decaying) on it can be source of smell. you may also find it wet, not good

  • beachinit46beachinit46 Member Posts: 2

    most of the things i have managed to find on this all say the 08 G6 doesnt have a cabin air filter

  • imidazol97imidazol97 Crossroads of America I70 & I75 Member Posts: 25,912

    @beachinit46 said:
    i found this forum while doing a search for the same issue, horrible horrible smell when the a/c or heat comes on and for a few minnutes when you turn it off. also noticing a moisture issue, the windows always fog, so has anyone ever found a solution to this? my car also is an 08 G6. seems like this problem goes all the way back to 08

    The moisture issue could be because the compressor is running and your are in an area warm enough to condense some moisture out of the air. After sitting that will cause fogging on the windows for a while after the car is restarted especially if it's below 50 and the AC compressor is not coming back on.

    But is the smell like rank produce left in the produce drawer too long in the refrigerator? Or is it the smell of coolant seeping from the heater core. To check, I'm going to ask you to smell the coolant in your car. If it has a pressure cap on the reservoir wait until the car has been off half an hour or so and slowly and carefully remove the cap and take a sniff of that coolant. If it's a nonpressurized reservoir with no warning label about pressure, just take the cap off.

    Is that the smell you're getting inside the car? A seep in the heater core will also give lots of moisture that wants to coat the windshield as the air blows over the warm, damp heater core. Usually people complain because the moisture on the windshield gets enough coolant vaporized to it that it smears when trying to wipe it off.

    2014 Malibu 2LT, 2015 Cruze 2LT,

  • maddog0324maddog0324 Member Posts: 55

    I have an '08 G6 2.4L that used to have this problem. I went to the local Buick dealership and had them enable the "after blow" feature for the HVAC system and have not had the odor issue since.

  • muffy1966muffy1966 Member Posts: 4
    i have a 2006 Pontiac g6. I can't get no heat from my car. on some days I get little heat. I can;'t drive my car in the winter months. I am at my wits end. can't figure this out. please any suggestions ?
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    What have you done/checked so far to correct the problem?
  • muffy1966muffy1966 Member Posts: 4
    checked heater core. heater blower actuator.

  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    So the lines going to, and coming out of the heater core are hot, or just going in?

    Or are the lines only marginally "warm" to the touch?

    Have you checked the coolant level when warm?
  • muffy1966muffy1966 Member Posts: 4
    the lines going in the heater are just going in.. the lines are warm to the touch, I checked the coolant level and its fine.
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    so both entrance and exit lines are "hot" or just slightly warm, or is one hotter than the other?
  • muffy1966muffy1966 Member Posts: 4
    one is hot and the other is warm
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    edited January 2017
    OK, well that suggests a plugged heater core or a defective heater control valve. You can I believe access this HVAC system with the proper scan tool and maybe even test-operate some of it through the tool.
  • imidazol97imidazol97 Crossroads of America I70 & I75 Member Posts: 25,912
    A plugged heat as Mr. Shiftright suggests is a strong possibility if the DexCool was contaminated with old style green antifreeze instead of Dex or Mixes with all colors. Some Gm owners had success taking off heater hose connections and back flushing gently.

    However, I'd ask if your blend door inside the HVAC box is working right? Are you able to adjust the temperature with the AC on from mild to cold with air coming out of the front vents? The motor on those doors is a common failure point and an easy replacement if you can identify which one and are agile enough to lie on the floor to take out usually 1 bolt holding it on.

    You can try engine off but key ON and see if you can hear the door operating as you change temperature from cold to hot and back,waiting in between. OR you can take off the plastic shield under the dash, probably on driver side, look up at the side of the box and with key ON change the temp settings even with the engine on. Look for a center hub rotating as it adjusts. If you don't get that, you can remove the motor and try to operate the door manually with engine on to see you can adjust the heat that way.

    Sometimes you can identify the other motors by change air direction and recirculate and seeing which ones those are.

    You'll need to get a diagram to determine just which motor is the blend door. Do you have dual controls for separate temps for passenger? And some of the labeling on motors in rockauto.com are confusing because the same motor may operate the blend door and different identical motor may operate the mode door that switches heat/AC/defrost directions for the air.

    2014 Malibu 2LT, 2015 Cruze 2LT,

Sign In or Register to comment.