Three weeks ago my 07gx with 160k over heated. I was able to pull off the road but not before a little hesitation when pressing on the gas pedal so I coasted into a parking lot and shut her down. Luckily I was across the street from auto parts store so I bought a thermostat and coolant and got to work. I haven't had a problem with over heating, I've driven 1k since and been great except for....
1) when I start the car there is the sound of water flowing behind the dash drivers side. Very loud
2). Smells of coolant when defrosted is on or climate control off.
Doesn't over heat, a/c works, heat works,all fluids are fine and did a flush and refill the week after. Should I burp the system again bad heater core or condenser? Thanks for your help.

 

Yes, you should burp the coolant system again. The sound of coolant from the dash usually indicates air in the system (if there was no air you wouldn't hear the sloshing). Do you get hot air from the heater without A/C and without revving the motor?

As for the smell of coolant, check for leaks. You really shouldn't smell any coolant this long after messing with your coolant system.

 

Yes there is heat at idle. I'll burp it again and check heat again as well.

 

Did your engine block get covered in coolant when it overheated or replaced the thermostat? I would try cleaning that up if so. I brought it to a car wash, covered up the air filter, set it spot rinse, and rinsed off areas where coolant dried.

Double check your connections.

On my Volvo I had to replace my heater core when it started coming in through the vents. Do you notice any gunk on the interior windshield? You'll notice a residue on the windshield if you need a new heater core sometimes.

 

Yeah when I pulled the Lower hose off, so I'll clean the bay it needs it.
Yeah there is residue on the windshield. I had a Volvo as well and figured it was the heater core. but because I haven't found any puddles of coolant I was hoping I didn't have to do that.

 

It could be an extremely tiny leak and the coolant is just burning off, but leaving the residue on the windshield. That's the same exact issue I had on my Volvo no huge puddles, but a sweet smell and crap on the window. New heater core fixed all that.

Not sure how difficult it would be to replace in the G though.

 

If the smell is not coming out of the AC vent's you may be OK. Usually that means a new heater core.

 

Thank you all. Unfortunately it's the heater core. Checked under the drivers mat again today and it was wet not very but still wet.