Had some symptoms of air in the cooling system - getting hot at idle/stopped, getting on the gas and temp falls to normal again. Heater blows cool/cold when temp is getting high. Never goes full overheat mode, but needle moving 3/4 of the way up the gauge and can hear cooling fans turn on. Doesn't get hot enough for the car to complain on the DIC or throw any codes (for now of course).
Anyways, had the system pressure tested and came back fine. Also had a combustion gas test done, and again came back fine. Had the system bled of air, but was told air is still getting in from somewhere. Car is doing better-ish for now, but I can hear gurgling from the driver's seat when cold and getting on the gas. I'm guessing the problem will come back.
I'm not getting any extra smoke in the exhaust, and car runs/idles/drives just as smooth as ever. Power is still there. I'm also not losing any noticeable amount of coolant, seeing puddles, or smell any coolant smells. Oil looks fine, coolant doesn't appear to be making it in the pan.
So it seems air is getting sucked/pushed in, but not sure how or from where. The place I had do the tests was stumped. Can it still be the head gasket if the combustion gas test and pressure test are both fine? If it is just fresh air getting in, how/where could it be forced in?
I have 110,000 miles, never had the coolant system flushed - still running Dex (probably original). Thermostat is original, but not sure if a faulty one could cause air pockets.
Any thoughts or directions would be massively helpful and appreciated!!! I'd love to keep my old girl up and running since I can't buy a newer one!
