I have had all kinds of over heating problems since I bought this car 3 months ago.I did a compression test after I was getting a p0300(random misfire).I also changed the plugs,wires cap and rotors.It still didnt fix the intermittent low idle and miss at start up.It's worse when the AC is on and I crank it up.It clears up after about 5 seconds.I am reading somewhere that the IAC,injectors or carbon build up in the intake could be the problem.
The Compression test all showed around 185-190psi.Fair enough.Mind you , when I thought I had a head gasket problem I used bars leak.That must have clogged up my radiator.Besides the compression test, I also did the solution test that identifies head gasket problems and it passed(the pump and solution).I have also used this solution called IRONTITE to clean out the junk in the rad.That seemed to have worked because the temp is at 195-200 at idle and with the ac on.

This is the second problem I am having....................Today I busted the upper rad hose and the car started to overheat while on the highway.This slowed me down but the engine was still running.I was trying to make it home .The car felt like it was revving but not moving.(I could only got about 25mph)I got home and changed the hose and filled it up with coolant and everything is normal.In research, something is telling me the cats were getting hot and that must have slowed down the car(back pressure or clogging while engine temps are hot).
Any ideas?