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Discussion Starter · #1 ·
2007 G6 3.5L, Manual Climate Control, 48,000 trouble free miles (until now)

Problem: No heat for the first 10 to 15 minutes of driving. Temp gauge rises as usual so the heat is there, just not getting any. Once the heat does make it into the cabin, it's HOT. I noticed this evening that the heat comes and goes as I drive. I can also do the remote start and after 10 minutes of sitting idle, still no heat. By no heat, I mean none, zero, zilch, pure cold air :(.

The fan works in all positions and all of the functions to change the direction of air work fine.

Any suggestions on what the problem is would be appreciated.
 

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Discussion Starter · #3 ·
Although I'm not a mechanic, from my past experience a thermostat problem with no heat would show up in the temp gauge not moving much (thermo stuck open). The temp gauge rises as normal, reaches about 200 deg then stays there for the most part.

A thermostat stuck closed would cause the problem of overheating, and I would estimate heat in the cabin rather quickly. Nothing smells hot and the temp gauge stays right where it's suppose to.

That said, maybe newer cars operate differently that what I'm used to working on.
 

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Check your coolant level. Sounds weird right, but on my old Lumina I had a problem with not getting warm air and it turned out that my coolant was bone dry.
 

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Check your coolant level. Sounds weird right, but on my old Lumina I had a problem with not getting warm air and it turned out that my coolant was bone dry.
BUMP!

Low coolant level means fluid isn't making it to the heater coils until you raise the RPMs.
 

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Discussion Starter · #8 ·
Update!

After I wrote my reply on the reason I didn't think it was the thermostat, I drove the car to work....same syptoms as before (although I didn't expect it to change). As I watched the temp gauge fluctuate (just a few degrees as the thermostat opened and closed), it was blowing cold air when the temp was hotter ~215 and warm when the temp was ~200. As I pulled into the parking lot at work, I saw the temp gauge spike to the max (red zone). I was still moving about 10 to 15 mph. I shut the car off and went into work.

My thought after seeing that is that the thermostat stuck closed, as I prevously described in my above post. After work, I drove the car to the parts store about 10 miles then home on the interstate about 30 miles....watched the gauge the entire way (while texting, shaving, reading the newspaper, and fumbling with the radio....no, not really :D). It read normal thru the entire trip. Now that I've had a chance this weekend, I looked a the coolant level....it is low, maybe down 2 inches in the reservoir, but there is still fluid visible.

Obviously, I'll add the coolant and see what happens, but I still have a couple of questions.

Will this minimal amount of fluid loss cause this problem (are newer cars more sensitive to this than older models)? Or, is it back to the suggestion about the thermostat?

By the way, I really do appreciate the responses!

Kurt
 

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If you have a leak in the cooling system then your system probably won't draw the remaining fluid out of the reservoir. Check the level after a few miles of driving. I still think its a low coolant problem, keep us informed (just in case we're wrong about the level).
There should be a bleed valve to ensure proper fluid level.
 

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Or the coolant system could be clogged...

When I had my symptoms with my old car it was bone dry not just a little low.
 

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If you have a leak in the cooling system then your system probably won't draw the remaining fluid out of the reservoir. Check the level after a few miles of driving. I still think its a low coolant problem, keep us informed (just in case we're wrong about the level).
There should be a bleed valve to ensure proper fluid level.
On the new cars the reservoir is part of the cooling system, nothing to draw from.
 

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Discussion Starter · #13 ·
No Heat - Problem Found

Sorry I've taken so long to provide an update; when you have 3 alternate vehicles available and you're busy, you just get in another one and drive it for awhile.

I did add about 0.75 gallons of coolant, which solved the problem of no heat. I now have plenty of heat. Thanks to all those who took the time to provide feedback on this problem.

But, as I suspected would be the case if I was low on coolant, I have a leak.

It looks to be coming from the water pump, although it's very hard to tell. I removed the belt to check for any slop in the water pump. There does not appear to be any radial slop (runout) but there is substantial axial slop (end play).

Is the end play normal? Is there any other "known" areas that might leak in the area of the water pump? I don't see coolant coming from any hoses.

Any suggestions and/or feedback on the leak would be appreciated.
 

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Uhh...as far as I know, there really shouldn't be any play in the shaft on the water pump.
 

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What happened to me

bout a year ago in the winter every morning i would drive and hot air only came out when i was moving. it was freezing so red lights were def not fun because the warm air would immediately go cold. turned out to be as simple as filling up the antifreeze. hope it works for ya :)
 

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Discussion Starter · #17 ·
No Heat Final Update

Once again, sorry for the extended delay. Removed air cleaner and other accessories looking for the leak; couldn't find anything. Then, I remembered the car had a 100,000 mile powertrain warranty. Read the manual....anything coolant related was covered.

Took it to the dealer and they replaced the crossover tube(s)? gasket. Tried to charge me $400 but I refused until they proved to me it WASN'T under warranty :mad:. It was....and it's fixed for $0, out of my pocket anyway!

Thanks for everyone's suggestions....most were right on.
 

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I'm having a similar issue with my g6. 07 2.4l manual controls. Heat does not come on at all. Temp gauge seems to be fine all the time. I believe it sits right in the middle constantly. I just came across this thread so I have not checked the thermostat or coolant levels. That's on the agenda this week. Also I'm having a problem with my air location. When I put it on defrost it only blows through the defroster as it should but when I change it to anything else for example normal front vents it will blow but also blow out of the defroster vent. Sometimes harder than others. Is there one actuator in particular that needs to be changed and also anyone have a how to for the job?
 
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