NHTSA Complaint #11541076 — 2005 BUICK RENDEZVOUS

I bought my car from a used car lot. I had it about 3-4 months and out of the blue it overheated very quickly, the warning light was on, some type of loud buzzer was going off so I pulled over and let it cool off, it took about 45 minutes but it started back up. I checked all the fluids and coolant levels and everything was ok. This continued to happen for about 3 weeks, quickly overheat, lights, alarms pulled over, checked fluids over and over. After about 3 weeks it would quickly overheat and then shut off on its own and several times it happened so fast I barely got off the road.i took it to a mechanic that drove it around a little until it overheated which at this point only took about 3 minutes to happen. He said there was air in my radiator and he released it and it was fixed, I drove about 3 miles and it overheated again so I returned to the same mechanic and after about 6 minutes he came and told me it was a head gasket but they didn't repair those there so I called the next closest mechanic who looked at the car for about 3 minutes, stuck an air hose in the radiator and he said it was blowing out gas fumes from the radiator meaning I had a cracked head. I had to tow it 200 miles to my house, my wife drove it back and forth to work which was only 1 miles from home, she was able to do that for about a month and then the engine would start stalling at different times such as slowing to turn, pulling in to park, and some times it would stall while driving in busy 4 lane roads. Well, a little over a month went by with all these things happening all the time and finally one day she came home from work and started to pull in the parking spot and it shut off again, we had to push it into the spot but once it shut off that day it has never started since