06 equinox with no heat..well sort of

I recently bought a 06 Pontiact Torrent (equinox) about a month ago it overheated after i had noticed the heater was no longer blowing warm. i replaced the thermostat and that seem to solve my problem.
last night i noticed at idle i had no heat again. the heat kicked on when i was driving and the car ran fine the whole way home. this morning i checked the coolant level and topped it off and let it idle in my driveway. same problem..no heat unless i revved the engine. the car isnt overheating at this point...but im afraid it might. i have a full warranty and roadside (thank god). any ideas before i wave the red flag and go in for service?

Possible air in the system? Is the pressure cap ok? A weak cap will cause this.

From the sound of it, it looks like you have a slow leak causing an air pocket....

By replacing the thermostat and bleeding the system, you removed the air pocket caused by the leak....but since the leak was not repaired, the air pocket has formed again....

Air pockets can prevent flow of coolant through the heater core....revving the engine can sometimes force the coolant through for heat.....when the air pocket gets too large, than there is no circulation at all through the heater core, which acts like a bypass for the cooling system....now the vehicle will start to overheat.....something leaking this slow could be the weep hole at the w/p, clamp on a heater hose, or lower intake gasket of the top of the engine.....I doubt it's a head gasket since it took almost a month for the problem to reoccur....

thats good news to me as i def dont like the thought of a head gasket job even under warranty.if it is the weep hole in the water pump will i physically see it slightly leaking while its running?
i placed a clean piece of cardboard under it last night after a good drive and didnt find anything so far. im going to continue to look. i also hear a swooshing sound on acceleration like water in a tube with air so air in the system def makes sense.
im a backyard mechanic myself with alright skills. is this something i should let the dealer check out and do you think this would be covered under warranty or is it going to cost out of pocket? i can continue my search for the leak or i can take advantage of the warranty i paid for...i just dont want to be handed a bill for something not covered that i could have figured out myself. any suggestions?...thanks by the way. this site has saved me a ton of money over the years and taught me a ton

If you haven't had to top it off. I would drive it and watch if you are losing any coolant.
If you can park it uphill, pull the cap and start it with the heater on full blast. Let it idle for a little while to see if you can "burp" the air out.

This is the tool that easily removes air pockets from engines:

http://www.lislecorp.com/divisions/products/?product=606

You install the funnel, start the vehicle, add just enough coolant so there is coolant at the very bottom of the funnel.....let the car run ....as the coolant heats up, coolant will rise slightly in the funnel.....when the level then drops quickly, that means the thermostat has opened and is pushing air out.....the level will drop well below the funnel....add coolant until the radiator is full to the neck and remove the funnel and attach the radiator cap...do this with the car running, and do it quickly.....careful the coolant will be hot......if you shut the vehicle off while trying to do this, you will get a surge of coolant coming out of the radiator....

Look at the top of the engine, under the throttle body on the driver's side and under the PS pump on the passenger side.....there are depressions in the top of the engine on the driver's side....look for coolant in a depression on top of the engine under the throttle body...if found, it's the lower intake gaskets....

pe boys wanted 40 bucks for that funnel system. i saw it on ebay for around 20 so i didnt go that route. i burped the system and sure enough i have heat again at idle. a lot of air bubbles came out actually. i suspect there is still a little more air in it since i do still hear that "swooshing" sound on acceleration. im going to burp it again today. i also replaced the pressure cap with a stant 9$ figured it was worth it.
i looked on the manifold and all around the top of the engine and didnt see any dex-cool, everything looked really dry. i still dont see anything from the hoses or spots underneath the truck. im going to keep looking and keeping an eye on the coolant level and go from there. thanks for teaching me how to burp the system...hopefully thats it :smokin:

This looks like a real small leak....may need to add coolant dye and use a black light.....

not sure if its a related problem but yesterday morning while getting on the highway the car was hesitating on acceleration. felt like a misfire but didnt make any noise. check engine light went on.
Caved in and took it into dealer this morning. i have full extended warranty so i figured let them deal with it. we will see what turns up...and what gets covered. they did shuttle me back home which i thought was cool and they are going to pick me up when and if the car is done today. hopefully if not ill get a loaner for the weekend.

my thoughts are...could it be that the head gasket is leaking slightly into the cylinder? mixing a slight bit of water in the combustion chamber causing the slight misfire? this could be why i havent found a leak anywhere and it seems like my air in the coolant problem is continuing slowly?

oh well let them figure it out. ill post my results on here so maybe they can help someone else in the future

water pump, under warranty and ignition tuneup..not under warranty but ill do plugs and wires myself. lets hope im good after this

my thoughts are...could it be that the head gasket is leaking slightly into the cylinder? mixing a slight bit of water in the combustion chamber causing the slight misfire? this could be why i havent found a leak anywhere and it seems like my air in the coolant problem is continuing slowly?


Actually my theory is this. When you have a head gasket leak the pressure flows from the cylinder to the coolant system, not the other way around. So a miss when you have a bad head gasket is due to the fact that when you attempt to compress the cylinder gasses, it just blows into the coolant system and forces coolant out. I had a 3.4L engine that had a bad head gasket and my first clue was a miss when I started it up. Then I had the almost overheat thing and knew it was a bad head gasket.

well the tuneup got rid of the hesitation problem. however the warranty didnt cover the water pump so i did it myself. pretty easy job actually. dealer wanted 400 bucks. the part cost me 60 bucks and it took about 2 hours and i took my time since i had all day to do it.
it worked for a week or two. im back to same problem again so the dealer mis- diagnosed it (cost me 100 bucks for dealer to look at it). im about ready to drive this thing through the dealership window :banghead:
im going to start a new thread on it in hopes someone else has had the same problems and figured it out

blkmonday, how did you end up finally fixing this? I am having the exact same problem and all I keep seeing is that others have ended up replacing the head gasket.

Check the top hose to your coolant reservoir. I pulled mine off and stuck a coat hanger into the reservoir. Turns out it was clogged and not allowing the coolant to recirculate back into it. Fixed my no heat at idle! Something so simple. SMDH! :banghead: