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Pontiac Montana Heating / Cooling Problems

2

Comments

  • jjallen07jjallen07 Member Posts: 7
    We dont have REMOTE Starter on the van. Again I have good air flow when the climate control is to the COLD side. When you turn the climate control to HOT, the air flow drops to almost nothing. You hear the air blowing in the dashboard, but very little is coming out of the vents.....Neither the vents on the dash or the floor board.

    If there are wires not connected I have no idea where they would be. The only remotes we have are to lock and unlock the doors.
  • kry99kry99 Member Posts: 1
    I have a 2005 Pontiac Montana (not SV6). This winter I have noticed more than previous winters....when you run the defroster you get air, but it never gets very warm. You can change the front to the floor and get lots of hot air, change the front to the A/C vents and get lots of hot air. There is hot air in the back for the passengers. Only on defrost do you have air that never gets warm. When you switch to defrost you can hear the deflector change and you can put your hand up by the windshield and go from no air to plenty of air coming out...it is just not warm.
    Any ideas?
  • notaminivannotaminivan Member Posts: 1
    edited March 2010
    Tell me it is not true that you have to pull the dash to change the struts.
  • armesarmes Member Posts: 32
    edited March 2010
    No it is not true. You can reach the strut mounting bolts from under the hood. The trick to it is that you must take the windshield wiper motor and wiper assemblies off of both sides. To do this you must do the following:

    1. Remove the wiper arm assemblies from both sides. They have a plastic cap which covers the actual nut. This just pops off with a screw driver. Then remove the plastic leaf guard that is under the wiper blades.

    2. Remove the 3 nuts that hold each wiper shaft assembly. The left one will drop out. the right one needs extra room.

    3. Remove the wiper motor assembly from the right side. I believe there are 2 or 3 bolts that hold it. Pull the motor assembly forward and drop the arm assembly down as you move it forward.

    4. You should now be able to access the 3 strut nuts.

    5. Remove 2 bolts from spindle assembly and pull strut down and out.

    6. Assemble is reverse of above.

    If you are just replaceing the strut tubes and not the whole assembly, you should think about changeing the strut bearing plates on top of the struts as they go bad usually before the strut tubes. If you feel and/or hear a poping/grinding noise while turning the wheels then the bearings are bad for sure.

    If you are replaceing the whole strut assembly, spring and all, then you get new bearings in the assembly.

    Sometimes it is best to have the alignment checked afterwards as you can disturb the alignment settings.

    Hope this helps you. :shades:
  • hurricane_dbhurricane_db Member Posts: 2
    i was changin my thermostat and i took off the throttle body the air filter as well as the hose that runs between the two.needless to say after 3 hours of fighting with the thermostat housing i got it all back together except one thing. i think its the vacuum hose on the hose that runs between the throttle body and air filter. somehow i managed to dislodge the hose and now i dont know where to put it back at. i tried to fit my hand and feel for the hole but i dont have a clue where it goes can anyone help me please!!!
  • mailmail Member Posts: 10
    I did the same thing... look for my postings under kennie. Now I am not an expert and if my memory serves me right (I could be wrong however) I do remember that the plastic tube that fits into the slinky air duct... the tube slipped out of the back
    of block... it just sticks in... if you clib under the vehicle and look between the rear exhaust manifold (just above) I think I recall being able to see it. Good luck...
  • hurricane_dbhurricane_db Member Posts: 2
    ok so here we go i have a 2000 pontiac montana that was overheating i turned on the heater and it was blowing cold air.i thought that was the thermostat that was bad so i changed it, still same problem. i then notice my coolant was pretty nasty with floaties that looked like some sort of stop leak so i flushed the system, still same problem. now im thinking the water pump but i dont know how to tell if that is the solution. the whole time it was overheating the cooling fans never kicked on so could it be something as simple as a relay or do i just change the water pump and go from there.im tellin you im gettin close to just throwin this van away.
  • sar781sar781 Member Posts: 3
    Someone please with knowledge help me, this vehicle has got a 3.4 lt engine, the check engine light is on, half my power has dissapeared, and theres a metalic screeching comes from underneath the vehicle when you give it gas. Also it wants to run hot because of this and I just had the plugs and wires replaced, oil changed ad new air filter put in. I replaced the fuel filter myself, that is good. Also when you give it gas you dont get much reaction from the engine, half of what its supposed to do, its got 153,419 miles on it, any suggestions????
  • armesarmes Member Posts: 32
    Did this problem start before or after the tune-up and oil change? :confuse:
  • sar781sar781 Member Posts: 3
    After the tune up, but right after I had the plugs and wires ect changed, everything run fine, its been gradually building up to this, last I checked the code reader from the dealership indicated something with the emission system ore something, cant remember.
  • armesarmes Member Posts: 32
    Overheating, bad emmission readings, rough running and loss of power can be caused by several things. Having too rich of fuel mixture and liaking head gaskets can cause all of these symptoms, Are you loosing coolant from the system with or without visible leakage from the cooling system?
  • sar781sar781 Member Posts: 3
    No I am not loosing coolant of any kind, it just has a loss of power, and a metalic vibrating kind of racket coming from underneath the vehicle when i gas it going down the road. Engine light is on, oil is good, so is the coolant. Fuel filter has been replaced its good. Might make a note here we did move from Oregon to Oklahoma, major climate change, is there a way to reset the computer without going to find someone with a code reader????
  • ecoffinecoffin Member Posts: 1
    Had the same problem with my 2002 Montana. Motor was over-heating but only cold air was being blown.

    On my first visit to the garage, the mecanic said it was my thermostat and changed it. The problem went away for two weeks and came back.

    Went back to the garage and this time he flushed by cooling system. This worked for about two weeks and the problem came back.

    I decided to change garages. This time the mecanic identified the problem! There was a tiny hole at the bottom of the radiator where air was entering and thus creating a blockage in the cooling system.

    Apparently, the reason why the problem was going away for two weeks previously was that air in the system was removed when the mecanic would change the thermostat or flush the line and it would take about 14 days to accumulate sufficient air to cause the problem to return.

    I am happy to report that the problem has not returned yet. Mecanic appears to have identified the smoking gun.

    You may want to check this out (very difficult to detect these holes because they do not necessarily cause a visual leak of Prestone on your driveway).

    Best regards,

    Eric
  • armesarmes Member Posts: 32
    You used to be able to take the fuse for the ECM ( computer ) and wait 30 seconds or so, put it back in and start/drive the vehicle for a few miles while it relearned everything. Now you have to go to the dealer and have them check/reprogram through there computer systems. Need to have engine codes read to find out what makes the check engine light come on. Most local auto parts stores will read the diagnostic codes for free. Garages charge $ 40 to $ 60 to check diagnostic codes. ;)
  • armesarmes Member Posts: 32
    I have a 02 that started overheating the same way. They told me I had leaking head gaskets. Spent $1300 for that and still had the problem with overheating and floaters in the radiator. Floaters turned out to be engine oil. I was coming from a small crack in the oil cooler. It was bleeding oil into the cooling system because the oil pressure was higher than the water pressure in the cooling system. They took the cooling lines off the cooler and bypassed them together. This isolated the oil cooler to oil only. After the engine warmed up, the crack opened up and oil started coming out the water ports on the cooler. Replaced the cooler, cleaned all the oil out of the cooling system ( hard to do ) and the problem went away. Cost $245 fo a new cooler. They installed it for free ( they got 1300 the first time for unneeded work )!!! The oil had coated the inside of the cooling system and reduced the ability to transfer heat. :mad:
  • julieinidjulieinid Member Posts: 1
    All I did was flush the radiator on my 2001 Pontiac Montana now it over heats like crazy! can't even make it out of driveway, what's goin on?
  • carfixer4ucarfixer4u Member Posts: 3
    Hi,

    Did you bleed the system? If not, some air is in the system and it overheats easily. So, have a look at two places which are identical. The first one is on left side and the other one on the right side. Try to see on top of the return heater hose along the valve cover on the top left side and near the thermostat on the right side. You will see a small screw on top of each place. These screws are the bleeders. Do you get them? Because these bleeders are at a higher level than the radiator, then some air is emprisoned in the system when the radiator is emptied. What you need to do is this:

    1) Feel the system with antifreeze through the plastic bowl on the right side (driver's side);
    2) Open both bleeders. If antifreeze does not appear, start the motor;
    3) Always watch two things: a) the temperature light or gage; and b) the airflow from the heater - put it on warm at maximum. A trick: when the air is warm, the motor is cool - if the air is cold, then the motor overheats...
    4) Let the motor running. You will see some antifreeze going out of both bleeder (you can go one bleeder at the time after a while, in quick alternance);
    5) When antifreeze will go out on a current basis (you will see some splashes coming from a mix of air and liquid), then no more air is in the system. So, make sure to do this thing for both bleeders.
    6) Be careful: if the temp gage is going up, just stop the motor a few minutes with the bleeders open. It could be useful too, in the process of evacuating the air, to press the gas pedal and have the motor running between 1500 and 2000 RPM. This accelerates the process.

    If you doing this for the very first time, you will have to coordinate several things at once. So don't panic. Follow the temp gage and never let it going up to the maximum. Stop the engine if it goes up 3/4 of the maximum (so a line or two above the midpoint on the temp gage). In some cases, you might need to repeat all the operation, as some air could take a couple of minutes to be totally evacuated.

    Yours,

    Denis
  • jennpagejennpage Member Posts: 1
    I have a 2006 Pontiac Montana....I live in Georgia so it is almost always humid down here. Recently my van started acting weird... Sometimes when I have the air conditioner on and I stop at red light or stop sign then press the gas pedal to go....it acts like it does want to go until I turn off the air conditioner. Then it acts fine. This does not happen all the time usually when it is very hot out. I don't think it is the transmission because it is not jerking or giving me any other signs to indicate it. Does anyone have any suggestions or may know what is causing this? Thanks :0)
  • gmcustsvcgmcustsvc Member Posts: 4,252
    Hello Jennpage,
    Have you had anyone diagnose your concern? Can you please email me your VIN and current mileage? You can get my email by clicking on gmcustsvc. Thank you,
    Mariah GM Customer Service
  • meanunclejerrymeanunclejerry Member Posts: 1
    This just happened on my daughter's 2000 Montana. The solution is to replace the alternator. It has 3 sets of diodes ; 1 for keeping the battery charged and the others for running your electrical systems.When the temp outside goes up, there is a problem with them sticking. replaced hers and everything's fine now.
  • pashukopashuko Member Posts: 3
    yes my 2003 pontiac montana on a long run wit the a/c on it throws the water to the inside and the carpet gets all wet wat can i do
  • ray80ray80 Member Posts: 1,655
    First and easiest thing to check if so equipped is the cabin air filters.
  • herbietteherbiette Member Posts: 1
    Ok I have a 2000 Pontiac Montana with 152K and while sitting in the van today with the car off keys in pocket the air conditioner came on and ran for aprox 5-10 seconds. I was puzzled and over the span of two hours it did this 4 times and each time it came on for about 5-10 seconds. Any ideas??? Again the car is off keys are not in the ignition and the air conditioner is on off. I'm wondering how long this has been going on and how often is it doing it....is it harmful to the van?
  • johnlocjohnloc Member Posts: 1
    Just happening looking into this forum for my overheating problem, I thought this might help someone else later as a pay back for others' useful inputs.
    I had this problem before and was thinking of changing the blower, but my friend at a GM dealer just changed the air filter at the heater core, I do not know exactly the location of it, it could be under the glove compartment where you can find the heater core, I believe. After that I had very strong hot air after that clogged air filter replaced.
  • jflettjflett Member Posts: 1
    ok was it the pump or the rad itself as i own a 2000 and it is doing the same thing just paid had thermostat changed heat for 24 hours and cold again thinking of a flush but afraid to do so if this is not the problem so just to double check if it was the rad or pump as your headline says pump but details lead to rad????
  • custominstallscustominstalls Member Posts: 1
    Your original post said:

    Last week, the heater stopped blowing in my 1998 Pontiac Transport van when I start it using the (ProStart) remote control starter. The van starts fine with the remote, but the headlights and heater don't work until I actually go in the van and turn the key to on. The heater is left turned on the mddle blower setting all the time, so it isn't a problem that it got turned off previously. Any ideas what would cause this? Thanks for any help!

    The PROSTART REMOTE CONTROL STARTER is a system that duplicates starting the vehicle with the key using a remote hence the name "remote control starter". At the ignition switch there are 2 accessory wires that need to be energized for the heater to work properly during remote start. When you are entering the van and turning on the key you are now energizing the second accessory wire that the PROSTART system is not connected to. This is a common installation error we see on a regular basis. There is a separate heater circuit that will not function unless it is properly connected. If the heat works fine when you start the vehicle with the key and not with the remote starter the problem is with the remote starter installation. If you have no heat with the key or the PROSTART system, that is a separate issue completely.
  • jjallen07jjallen07 Member Posts: 7
    GMCUSTSVC! Maybe you can tell me why my van doesnt put out hot air when climate control is on hot and also why when you go to HOT the air flow goes to about 20% . The GM tech up here said there was a damper he wired in a way to make more air flow but you could fool me with what he did. WE dont see any true improvement and it gets cold up here in MICH.

    Thank you :mad:
  • jjallen07jjallen07 Member Posts: 7
    Your post to jjallen07 is confussing me .. I am jjallen07 and own a 2004 Montana and DO NOT HAVE A REMOTE Start.....Have a large air flow problem when i go to heat. HAve good air flow in COLD Mode but only maybe 20% airflow in HOT. A GM TECH wired a damper in a position that was suppose to give us beter air flow but it didnt...takes for ever to get the car heated up (25 to 30 mins) and then it is only warm enough to keep from freezeing. If we didnt have rear heat/air i think it would be undriveable in the winter...... :mad:
  • newt25newt25 Member Posts: 1
    I have a 2000 Ponitac Montana. The A/C works on the back vents and on the right side dash vents, but NOT the left side dash vents. I only get luke warm air from the left vents. Any help would be appreciated.
  • reikureiku Member Posts: 2
    Ok I am sorry up front if there is am answer to my issue. I really did read a lot of threads. That being said. I have a 2002 Montana. The ac blows warm. The temp knob works to turn on heat just fine. I pulled out the unit with fan sped temp and placement of air flow. It's electronic. I checked board and saw no burn spots. The wire hat ears that attach seem fine as well. The compressor does not come on as far as I cam tell seeing as I never feel or hear drag. I had a friend that tried to charge it with freon. Assuming it was low side port that between engine and radiator by the heat shield to exhaust? I was told it would not take any. I checked the condenser for leakage and see none. I read compressor will not run low on freon. Is that right? Is there anything that would cause the compressor not to run. The ac worked I turned it off the shortly later tried to turn it back on and nothing Texas heat is unbearable this time of year. Any help would be amazing.
  • laboymclaboymc Member Posts: 1
    Hi,

    I have a 2000 Pontiac Montana and the A/C when I turn it on won't turn until I reach speed 4 or 5 and when it does it goes on and off. The air is cold and I don't have problems when the air comes out, which comes out cold. The problem I am having is that it doesn't stay on. What is the problem when something like this occurs?
  • howard741howard741 Member Posts: 2
    I have the same problem with a 2002 Montana. In the cooling mode, the cold air on the right side is excellent, but the two left vents for the driver are "half-cool". I suspect that a damper or flap is not opening or closing all the way, and thus allowing outside warm air to be mixed with cold air, but only for the left side. Anyone have suggestions on where to start under the dash?
  • eaglepepeaglepep Member Posts: 1
    As you may have noticed that the first post in this topic the owner complained of water coming out of the vents. The 2003 model of the Montana had serious condensation issues with the airconditioning. GMs solution was to install an aftermarket kit that activates the blower when humidity levels get too high in the condensor box. The reason they came up with this solution was to PREVENT Legionellosis (Legionnaires' disease, an advanced form of pneumonia) from forming in the condensor box. SO THE ANSWER TO YOU QUESTION IS THAT IT IS NORMAL FOR YOUR AIRCONDITIONER BLOWER TO KICK IN FOR 5 TO 10 SECONDS EVEN WHEN THE KEYS ARE NOT IN THE IGNITION. HOWEVER, this can lead to a dead battery it you live in a high humidity area! The only way to prevent this is to install a deep cycle marine battery. ALSO BE WARNED: IF YOUR FAN EVER QUITS AND THE FUSES IN THE FUSE BOX ARE OK, YOU HAVE TO CHECK THE FUSE FOR THE AFTERMARKET KIT, FOUND BEHIND THE KICKPANEL OF THE PASSAENGER SIDE DASHBOARD.
  • jessikay444jessikay444 Member Posts: 1
    I just bought a 2001 montana nd it makes a whining noise when turnin kinda idols high nd today it over heated on me the heater works selectively and to fix the problem as soon as possible any ideas??
  • jpfjpf Member Posts: 496
    Check for low engine coolant. Most likely it's the intake manifold gasket. Good luck.
  • howard741howard741 Member Posts: 2
    Review the message board back to message 60 and come forward. Some good insights here relative to overheating and to heater and cooling problems. My left right A/C vent temperature problem (see # 79) was partially cured by removing all the plastic under the sterring column. Then lubricating all levers. I also repositioned a ground strap that was interfeering with one of the moving levers. Back to your over heating issue: If you are in a warm climate, remove radiator cap, add water hose, run heater, idle engine, open drain on radiator. Check cabin air filter for cleanliness, vacuum as required(2 of them), remove thermostat or replace. Keep us informed on your progress. Howard741
  • zuccyzuccy Member Posts: 1
    I have a 2007 Montana with just over 100k and I started having the exact same problem. I checked the rad fluid level and it all seems ok. Did anyone ever find out what the exact problem is ?
  • nygentnygent Member Posts: 1
    edited November 2011
    Anyone know if the 2003 Montana has Bleeder Valves for the Cooling System? If yes, locations of these?

    Possibly have air in system likely due to intake gasket leak although not sure yet. Also have P303 misfire but unknown if related to gaskets. For now I need to be able to get air out of cooling system due to temp guage spikes and warning light of Hot Coolant.

    Any other methods for bleeding air appreciated. Heard one person suggest parkin vehicle on hill with front end higher than rear then using funnel in radiator filled with coolant to then bleed valves, keep funnel filled...repeat. then run engine bleed valves while funnel still filled. Do until no more air escapes valves.

    Finally if air bubbles come from radiator cap opening it indicates likely intake gasket leak. Is this a good idicator of intake gasket leak?

    Thanks
  • jjallen07jjallen07 Member Posts: 7
    edited November 2011
    I had taken out my filters along time ago thinking it was that. I have also had it to the dealership twice. They diabled the air restrictor flow damper but that did not help. Still have VERY LOW AIR FLOW in HEAT ONLY. Heater Core replaced, Thermostat replaced, GM even checked the fluid flow. I can tell you that the CORE gets hot, as I have experienced the heat when touching it while trying to trouble shoot the air flow. A/C is ok. Think there is a flow ristriction that GM doesnt even know how to fix. IF I could i would remove some of the "flow doors". I believe that this is a design flaw that after several years of heat and cold, the plastic DAMPERS warp and do not function correctly. ....... :Just a note, that "fix" cost about 600.00 to do nothing....Thank God we have a REAR AIR/HEAT on the van or it would never get warm.... :sick:
  • montana999montana999 Member Posts: 5
    I have a 2000 Montana with 280,000 km ( 175,000 mi ).
    2years ago I changed the rad. (It was heavy with sludge ).
    I flushed the heater core.
    I changed the thermostat.
    All new hoses and new antifreeze.
    Works good now.
  • adillardadillard Member Posts: 1
    hi kenni

    i have an o2 montana, been having heater problems as well like everyone else that owns one of these vans. my van does not have a rear heater will it still have an aux. heat pump, this morning it just blows cold air and is now over heating it is full of coolant. and when u turn the knob to change it from defrost to floor or vent u can hear it changing and it blows plenty of air it is just cold air instead of hot . my husband thinks it is the thermostat sticking causing it to over heat but u have to take the top part of the motor apart just to gret to the housing . i am really tired of this . do u have any ideas thanks
  • kenniekennie Member Posts: 38
    edited December 2011
    I am no expert and can only provide recommendations from experience. I have a feeling there are a few potential problems from more likely to less likely: plugged aux pump (if you have one), medium head gasket leak, minor head gasket leak, plugged heater core, interior heating vent door not operating properly. Your motor is not overheating it is not the thermostat.

    Can't remember the last messages i've posted but I was able to get heat back by flushing (myself) the heater core... of course in the most environmently friendly way - probably more-so that any garage would spend the time to do - see my previous posts on this. Lots of crap came out of my system and i figured I had the problem fixed. I took appart and cleaned the aux pump as it was completely blocked - another reason for no heat. I blead the system of any air, replaced the thermostat (but this is not really related to the heater core in this case) and bob was my uncle... best heat ever.

    About 4 months later, I started getting rough idling... and could smell antifreeze.... I knew right away my head gasket let go and stopped running the van immediately. The cost to have my head gasket replaced (including new radiator - because I pull a ski boat with my van 3000k/yr on holidays) was around $3000 at a local shop. That explains why I was getting air into my system in the years previous causing overheating, poor fluid flow, limiting heat, etc. but it must have been minor enough that I did not see antifreeze in the oil or smell antifreeze in the exhaust so I didn't know.

    If your motor is overheating your head gaskets might be going and causing air to enter your system not allowing the fluid to flow. This is major problem with this van, BUT there are things you can try before going down this road. Just keep an eye on the oil (look for brown color - signs of antifreeze in oil) and smell of antifreeze in exhaust. The exhast will show signs of white/grey and if this is the case don't run the vehicle... you'll bend your push rods or damage your shaft and then your motor is pretty much toast. This could be a cause of overheating. Second reason is a failing thermostat.

    1) run the vehicle and monitor the hoses going to/from the heater core - do they heat up? Is the return heater hose from the core heating up just as fast?

    2) Unless your vehicle is overheating, this is not a cause of your heat in the van but, release any air you have in your system using the two pins (one on tube coming out of water pump and the other near the thermostat housing while the vehicle is idling. Be careful, you just want the air to escape, not the fluid. See how much this helps, notice how much air comes out... if there is allot it could be a head gasket leak.... but if you clear it and then the air eventually comes back, you'll know. 3) Might be worth changing the thermostat. If you don't have alot of patience, this is a real pain in the [non-permissible content removed] and probably I would not do this again myself. But if you are taking it in for this then maybe you should have them do a diagnosis

    3) If you have an auxillary pump (from the sounds of it you don't), lookup pictures on the internet for location. It is a magnetic motor driven pump at 10oclock of your antifreeze overflow container on RHS of the vehicle compartment... you can't miss this as it has a couple wires going to a sensor between the bumper and the rad. I cleaned mine and it was horrid... don't think any flow was getting to the heater core and is the only route to get there. I have given instructions for this in previous posts as well. If you do this, you might as well do #4 too.

    4) use my proceedures to flush the heater core.... see my previous posts and i have given detailed instructions how to do this being highly environmently friendly. If your heater core is truely plugged, you will know because you will be able to tell what the flow is when you flush it.

    Final comment:
    These are ONLY suggestions based on my experience. If you want to save yourself some headaches after bleeding the system of air first and it does not help the heat, I would book an appointment to have your heater core flushed and your aux pump cleanned. My feeling is that your thermostat and pump and potential gasket leaks have little to do with the heat in your van if your van is not overheating. It is a pretty simple thing, there is likely no fluid flow through your heater core or not enough to allow you to get any heat. If you put the blower on the lowest spead and the engine is running at operating termperature you should feel some heat... if you feel none after some time it is either flow problem or a door is stuck... I highly doubt a door is stuck but again, i'm no expert... I can see the door binding and not fully closing or opening - this is possible. The vents work on air presure so if you hear them moving you should know they are working.

    If GM came out with a new extended pontiac montana van I would buy it in a second. Yes, i've replaced head gaskets but it is the most versitile vehicle on the road as long as you are willing to be constantly fixing things - no more than any other vehicle in my opinion. Good thing about it is that it keeps running and I can pretty much fix everything myself if i'm feeling broke to save dealership prices. If you are not that way then this van could be a money pit for you.

    Keep us posted on what happens !
  • radtadradtad Member Posts: 1
    I am having an issue with my 130,000 mile 2006 Montana not sharing its heat. The van does not over heat and is running at a normal operating temperture. It will give off a little heat and three seconds later blows cold. For awhile it would give off warm when you were driving and it would go cold at stops. It has even stopped doing that. Serpentine belt broke two months ago and replace it. Just replaced the EGR valve and the cat. I also had to replace the fan knob that got broke. Any Ideas I am thinking maybe thrmostat, or a blockage in the heater core maybe?
  • kenniekennie Member Posts: 38
    You can see my other posts on this... there are quite a few. But based on what you are telling me I would guess that there are two aspects to your problem -maybe a third. I've experienced EXACTLY the same thing with this van. The head when it is cold out -15bones is not great even right off the factory line - so you can't have a high expectation off the starting line. If you are rear heat and the vehicle is purchased in canada or cold climate area then it probably has a auxilary coolant pump. It is located inches from the front/left corner of the coolant reserve when you are facing the vehicle. The pump is actually a motor with a magnet that drives a fan that pushes fluid into your heater core and to the rear heater core. If you have one of these they get bungged up... my van is a 2000 and this was my problem... the fan was no longer turning and was completely bungged up... your van is a 2006, I can't imagine this happening so soon but it is possible. I flushed my heater core myself and cleanned the aux pump and all was well - i have extensive posts on Edmonds on what I did number kennie. If your motor is not overheating then I cannot see what a thermostat change would do to help... it is already opening/closing if you are not overheating. The only other thing could for you to add coolant or bleed air out of your system using the two pins... possibly you are not getting enough flow but I doubt this would cause your low heat issues. When I sped up the engine I had more heat... this would explain that you are not getting enough fluid FLOW through your heater core... thus the aux pump or core bockage. When I flushed mine (both ways) allot of debris came out. Good luck.
  • kmongerkmonger Member Posts: 1
    I am not sure when this issue has started as I don't run the a/c when I drive. My husband does when he drives. We are pretty sure we have a leak but can't find it. Any suggestions?

    Also, when we put freon in it gets cold and blows cold air out the front but blows hot air out the back. Does anyone know what is causing this? Please help we need air in the back for the 4 kids. My husband touched a pipe or hose on the bottom of the van while he had the air on and it was really hot. Any idea's or help please!
  • reikureiku Member Posts: 2
    ok last summer I hade a radiator that the trans. cooling lines cracked and trashed the trans. I had the trans rebuilt and the radiator replaced as well as the fan assembly. I had not issues at first but after a couple of months I started having problems with overheating. I assumed since the hoses had not been replace that I was loosing coolant and would just add. Now about 3 months ago I noticed that I had what appeared to be a rust colored back flow into the overflow res. Now recently the van started overheating again and i noticed that there was poor flow of liquid. I replaced the thermostate. Oh yes it is hard to get to thermostate but I removed nothing but the hose and used a wrench on the back bolt. So yes it is possible with patience. Anyway, I still had issue. I did not know that the system needed to be bled. I was traveling the next day down the road after replacing the thermostat. It overheated so i pulled over and turned of the engine. I waited several min trying to let it cool enough to get me home since I was a couple of miles out. I could not get it started. after several attempts and almost an hour a gentleman stops and got it started. I got home and turned it off as soon as i stopped moving in my drive. I let it cool and started the engine and was in the process of trying to bleed the air out. The engine started making a wierd noise and was shooting water and air out of the radiator opening. I quickly shut the van off. I waited till the next day and now the thing will not catch. I know I get spark and gas as it tries to catch but will not stay running. I have read several post but have not seen someone post the same problem. Any ideas? Thanks Lisa
  • meghan101meghan101 Member Posts: 2
    My 02 montana sat for 6 months i got it about a month ago, havent ran it that much, but changed the coolant, thermostat, and now it over heats, have bled it and everything, was fine for a week or so, started it up today and its over heating and white smoke is coming out the tail pipe, went away after 20 mins, now when i say over heating it doesnt red line but comes close to it. also have given it an oil change, havent seen anything or smelt anything different in the oil. signs and people have said head gasket is this the case or should i try something else. would hate to pour more money into it then i already have!
  • nogm4menogm4me Member Posts: 13
    I am not totally familiar with the Montana van per se, but I do know that 2006 was the time frame of the evil Dexcool engine coolant. There is a class action lawsuit that has now expired that speaks to the chemical reaction of this coolant when heated and exposed to atmospheric air for a prolonged period. ie: as when the coolant level has become low. The material turns gelatinous and can stop up the heater core and other critical cooling hardware. It happened to me when engine service was being performed. The other reply has the person diligently flushing out the cooling system and replacing it with some of the more excellent non automotive manufacturer producers of coolant. The global coolant has superb all-around properties and compatibility. You may wish to convert to better coolant.
  • lanateclanatec Member Posts: 1
    I have a 2002 Pontiac Montana that will not switch from heat to A/C. I have been able to run A/C all summer but when I switch to heat, it blows luke-warm air. Then when I switch back to A/C, cold air comes out of the upper vents but the lower vents still blow warm air for a while. This started happening last winter - couldn't switch from heat to A/C because I wouldn't get cold air. Finally got the cold air from the A/C but now can't switch back to heat. Initially the level 5 on the heating fan switched stopped working and prior to that I would have to turn the heating lever all the way to 5, would hear a pop or click sound, and then it would switch from A/C to heat. Could this be the problem (not being able to get to level 5) or could it be something else - interior heating vent door perhaps?
  • jjallen07jjallen07 Member Posts: 7
    Just a update to this post .... I have finally figured it out. Just recently, the Hear/A/C control center on the dashboard started to act up. The different levels for blower speed started to not work. Then I smelled an electrical burning smell...finally the blower stopped working and the knob for the blower speed selector broke. I went to the salvage yard and picked up a control unit for a 2001 montana and installed it.....NOW I HAVE GOOD AIR FLOW!!!!!!!!! GM could not even figure this air flow problem.......

    This raises some serious questions about the safety of the wiring harnesses in this car. I have had to replace the rear break light assembly due to the houseing burning out. Now I find this on the heater control center. The fuel gage does not work properly...This too is noted as a electrical problem.....UMMMMMMMMM
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