Hey guys I've been having problems with my alero 3.4L for the past few weeks since I've changed my lower intake gasket and flushed my antifreeze and I'm honestly out of ideas on what to check next!
So yeah basically what's going on is that when I start up my car everythings fine my heater throws out decently warm air as my car is warming up but as soon as the coolant temperature starts getting close to the thermostat temperature all of a sudden my car just starts blowing out Ice cold air from outside for like 10 to 15 seconds and my temperature gauge goes almost to the 3/4 mark and then it drops down back to half and my heater starts throwing out really hot air again all of a sudden! Its so freakin weird and its driving me crazy trying to figure out whats going on! I've tried bleeding the coolant multiple times but it doesnt help and my coolant tank is full to the max cold line so it isn't low on antifreeze.
Also other things i noticed but im not sure if its related to the problem or not so im theowing it out there to see if it helps but if my coolant is hot and pressurized is my coolant level on my reservoir supposed to go up or down? Because the other day i checked it and i noticed it was like 1/2 an inch under the fill line so i thought maybe i have a leak somewhere? For the mean time i was gonna add some more antifreeze and as soon as i loosened the cap and let the pressure bleed out i looked at the tank again and all of a sudden my coolant level is back to where it should be? I never noticed that before so i dont know if its normal or not. If i had to take a crazy wild guess tho I'd say i probably have a bad hose somewhere and when it builds pressure the hose expands slightly like a balloon and holds more antifreeze than normal but thats just a crazy guess
