99 GA 3.4L Inconsistent hot air/ overheating

OK Guys I'm a newbie to this forum but not to working on cars. I just bout this car and am having issues with it overheating and not blowing hot air consistently? At idle w/ cap off the temp will stay at ~200 degrees. With the cap on and at normal driving speeds the pressure will hold at 15 - 20psi, but will at times push fluid past the cap? I've tried to burp the system and think that I have all the air out using the purge port. I have replaced the cap and thermostat. One thing I did notice is that one of the coolant line going to the heater core was noticably warner than the other, but I dont think it is plugged because the car ran fine for the first three days after I bought it? Any Ideas? Thanks

Still sounds like you have an air lock. What's the cooling fan doing, should cycle on at aprox. 1/2 guage mark. If it's not doing that or you're getting irratic guage readings that points to an air lock.

Best way to bleed is to bring the engine speed to aprox. 1300-1500 rpm, cap off, coolant bottle in hand. Let it run until the fan kicks in, keeping the level up. If you find all is good again but problem returns after a few days, look into an internal leak.

Thanks for the reply. The fans are running, tho I don't recall when they are coming on. Gauge does fluctuate 185ish to 230ish while driving and sometimes then goes high and pushes fluid out the overflow. As far as air lock bleeding when you talk about the coolant bottle, are you saying to dismount the bottle from it's location and hold it above the engine leaving the coolant lines intact? I'm wondering if I have a head or head gasket issue allowing exhaust gases into the coolant system?

I have a 99 grand am 3.4 and it was spewing water like that i drilled few small holes in the thermostat and it has been fine ever since but it takes a lil longer to fully warm up. If you deceide to try that get a 180 degree thermostat.

Well it aint looking good. I did a combustion leak test on the coolant system and it came back positive. So it would appear that I have a bad head gasket or cracked head! I guess it's time to open up the motor and see what is going on?

The lIM gaskets could possibly cause that problem but if u go that far might as well do headgaskets as well. Does the car run very rough or miss? my 99 ga ha dsimilar problemsand water in oil but ran jus t bout perfect but i tore down the motor and it was a blown LIM gasket 16 more bolts and 1hr replaced head gaskets. Good Luck its not very hard just b sure to USE TORQe on bolts black rtv silicone and thread locker

Well I dug into the motor over the last few days and after pulling the heads found that both were warped. I had to take .016" off of the front hd and .024" off the rear. The good news is that seems for have fixed my problem, I've got HOT air and she ain't overheating (and got my stepdaughter off my a**). Oh, and by the way I did replace the LIM gasket and all hd and manifold bolts and drilled the thermostat. Thanks for the feedback guys, much appreciated.