2007 Pontiac torrent air in coolant system no heat

[puzzled]

lost heat.. heat on high idol lost on low rpms.. had thermostat changed, rad flush 3x, combustion/ck heads gd, fans gd, rad cap gd, water pump gd. blend doors gd..
left heater core mechanic reluctant to change..
heater core, coolant temperature sensor . only thing left can think of y air continues and lose heat.
any ideas?

 

[melsg5]

Did he perform a pressure test and if so how long did he monitor gauge?
Did he perform a cooling system hydrocarbon test?
Do you smell coolant inside and have you checked the passenger side carpet for moisture?

 

[ruelbraker]

lost heat.. heat on high idol lost on low rpms.. had thermostat changed, rad flush 3x, combustion/ck heads gd, fans gd, rad cap gd, water pump gd. blend doors gd..
left heater core mechanic reluctant to change..
heater core, coolant temperature sensor . only thing left can think of y air continues and lose heat.
any ideas?

Hi I am a new member had a radiator shop for 22 years and it took me that many years to figure out I did not want to do it any more. If it was my problem i would first look at the door that divides the hot air and cold air had one once that the cable housing attachment was broken and the door would not close all the way also the doors have a seal on them that was not very thick and age could erode the seal but I don't think that would make that much difference. One thing I would do regardless would remove the heater hoses from the engine you would need to check how much pressure your garden hose puts out if it is 14 psi or less you can attach a garden hose to your heater hoses and run water through the heater backwards first then froward if you get no flow the core is plunged this will mean that you have two options first is you could raise the pressure slowly and change the directions you are flowing the water and you can continue until you get a flow or the heater core starts leaking it should leak on the firewall under the hearer box or inside the floor board if this happens you will have to replace your core. Two more thinks to remember the heater hoses have been on your car for a while the hoses maybe stuck to the hose fittings and if you work the hose to hard to remove the hose you can break the fitting off especially on the heater core so I always cut the hoses off the fitting the hoses are cheap and sometimes are long enough that you can cut part off and still fit and be sure what the material the fitting are the newer hearer cores have plastic necks and you can cut a hole in one easy and you don,t want to do that. Last thing if you replace the heater core you will have the option of the factory copper core or the newer aluminum core if you go the aluminum you must keep good antifreeze in your system. I hope this helps Ruel

 

[Cavell]

Just saw an equinox for sale with leaky heater core. $1k which is more then I paid for my torrent. I did the core flush on my last equinox. Had so-so heat. Reversing flow helps. You remove hoses from tee, not firewall. Easy to reach.

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[puzzled]

so..
as of now combustion test
rad flushed, hoses reversed flow ,bled multi times
thermostat
water pump ckd, gd
heads are gd
blend doors
just changed out heater core

did not fix it!
still getting air
still heat high end speed 2000rpm plus and no low end heat

whats left?? mechanic is lost

 

[melsg5]

What does "still getting air" mean?
What position is the engine temperature gauge?
What temperature thermostat was installed?
Has the thermostat been removed and tested in a pot of water, brought slowly to a boil and was observed starting to open when simmering before boil?
Has an IR gun been used on the heater hoses?

 

[puzzled]

air in the lines..yes un gun and on new thermostat ckd

 

[puzzled]

temp gauge just under half..gd
high rpm heat.. loses heat completely on low rmp

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[melsg5]

I understand what the problem is.
Did you test the new thermostat and what temperature thermostat is it?
What did the IR gun show on the heater hoses?
Are you aware there are two bleeders, water pump and thermostat housing?
Exactly what was done to bleed the air from the system?

 

[puzzled]

the mechanic did testing..just said ir was gd. he flushes and bled thermostatic..reversed lines flushed..
not sure of water pump bleed..he never said that..
hows waterpump bleed work

 

[melsg5]

So you can't answer the questions since you trust the mechanic knows what he is doing?
Didnt bother trying another thermostat and you dont know what temperature he installed?
He's supposed to bleed water pump first.
Bring vehicle to operating temperature and then bleed thermostat.
Is your mechanic ASE certified?

 

[puzzled]

hes been business over 20yrs..
i did ask to try another new thermostat..he said it was fine.. as for bleeding water pump then thermostatic..im insure if did.. but i will reask..thank u

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[melsg5]

There is always the option of another shop or you can try bleeding the air out of the system.
Google "GM 3.4 cooling system bleed ".

 

[davidawg]

lost heat.. heat on high idol lost on low rpms.. had thermostat changed, rad flush 3x, combustion/ck heads gd, fans gd, rad cap gd, water pump gd. blend doors gd..
left heater core mechanic reluctant to change..
heater core, coolant temperature sensor . only thing left can think of y air continues and lose heat.
any ideas?

Did you try flushing your heater hoses and heater core

 

[melsg5]

Did you try flushing your heater hoses and heater core

Read post 5

 

[puzzled]

heater core replaced now too..
going go different mechanic mine..ran out ideas..
still air in coolant
drive no heat on high rpm or low now
lower gear and 1 gear.. really gd heat
so confused, me and mechanic.
never heard that!

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[Cavell]

I got an 07 torrent in July. Had a stuck open thermostat. And a number of elec issues. we have driven it maybe once a week and I always hear a heater core gurgling at start. Heat is good At all vehicle speeds. I have done 3 equinoxes for headgaskets so I know how to bleed the system. Always use the WP bleed screw and sometimes even park on hill with nose up. But I’m not sure I have a problem. Guess I have no real crisis yet to look at it.
i think the bleed screw is sheared off? Ha, gotta look again.

 

[puzzled]

long journey.. in end ..one mechanic said head gaskets were gd..different mechanic.. they were going and erg sensor.valve
expensive lessons.. apparently the previous person put block sealer in to hide problems..
fixed now and all new parts added lol

 

[melsg5]

Thanks for the update, sorry it was such a long journey

 

[sobitthen]

I have same issues, swapped core last summer, smelled AF once in a while, did the cheat where cut metal lines under dash and spliced with short pieces of hose, no need to pull whole dash that way, just part of console and gas pedal. I could not locate the thermostat housing bleeder, only found the water pump one, swapped water pump at same time and that front engine mount, she was riding low...
Anyhow will look again for bleeder on thermostat housing.. -25F to -40F wind chills for the next week starting today, hope there was trick here to find..
Had same issue, if rev up heat, if idle, she cools down, haven't brought thermal gun out yet, but hand test thought both hoses were close to same temp, hot...
My back certainly hopes there isn't similar issue with bad head gaskets, temp gauge sits just under half, drove for a year now, think would know..
With pandemic, did not get a lot of miles in to know had heat issues until few weeks ago, only drive couple miles every other week for supplies.