I'm new here and it's a pleasure to be amidst the Pontiac GP family. I love my car, but like so many here, it also comes with a few mechanical/technical issues that it has picked up with age (and lack of quality service). I wanted to look for some solutions to some of the problems I have had, so I wanted to compile a brief history of the car while I have owned it.
I purchased a used 2006 Pontiac Grand Prix 3800 V6L Series III about a year and a half ago at just over 100k miles on it, previous owner seems to have neglected much of its service. I had to put new brakes on it, turn the rotors, replace plugs + wires, oil change & filters when I got it. Regular service and oil changes during my ownership of the vehicle.
It overheated in December, after it has been consuming an unusually high amount of oil, when an elbow feeding coolant into system burst and spilled the coolant fluid out over the motor and highway. In march (three months later) it began overheating again. I was told by my mechanic that it was a faulty thermostat. I replaced the thermostat. Three months later, in June, it began overheating when idle, but would cool down when returned to motion. Dealership held car for two days, and when I came back to seek the answer for why it was over heating again, I was told that I had either cracked the engine block, or blown a head gasket, in either case would amount to a significant cost - translation: get a new motor (car has about 135k mi on it at this point). So I put a used motor in with 92k miles in it about 8 weeks ago. It was never explained to me why it was overheating in the first place to have even caused the supposed engine damage initially, or why it was able to be driven in its condition (in excess of 150 mi) supposedly with a broken motor, or a motor with no lubricant (blown head gasket). My check engine light has remained on, and a message "Check Gas Cap" comes on once motor has been running for approx. 3 minutes. I replaced the gas cap, and the message still displays, check engine indicator still illuminates.
One issue, prevalent since I've owned the car, with Air conditioner is that it only cools when on recirculate mode, and then the compressor seems to turn itself off, and then back on during operation. Is this normal? I took it to a new mechanic shop 4 weeks ago to check on what I suppose (correctly) is a wheel bearing that has worn out. I have the bearing assembly replaced, and while it is elevated on the rack, new mechanic points out several issues that the dealership and other mechanic shop did not inform me of: it is slowly losing some of its trans-axle fluid from the pan gasket, and radiator fluid looks like muddy water (indicating significant amount of rust in radiator). So, my question is, whether the radiator condition could have been the source of the overheating (and still pose that risk even now) and that I needlessly purchased another motor, and that a matter so simple could be overlooked by two sets of mechanics? And what could be causing the check engine indicator to illuminate?
I look forward to meeting everyone and of course some thoughts on what may be going wrong with my car.
