It has the plug. I did cancel it because Tl;Dr, it refused to start in my job's parking lot. Had to get it towed back to the shop. Was not happy with the man, chewed him out a little, and with how sheepish he was acting, I'm getting it back quicker than 2 weeks this time. I'll consider your scanner after I get the repair bill lol
Well, best of luck with it! As for troubleshooting, it's an important distinction as to whether your car is a crank no start, or no crank no start. If it's a crank no start, it could be a particular sensor, or the fuel pump, or something like that. A no crank no start could be the starter motor, a relay, the immobilizer, etc.
It sounds like this is your second trip to the mechanic. Try not to chew them out too badly, because they might use aftermarket parts - maybe the OEM part is expensive or difficult/impossible to obtain. Most of the time aftermarket parts are fine, but sometimes they are junk. Forums for your car will probably have information about what aftermarket parts are good, and what aftermarket parts are not good.
Good luck!
I had a lot of power loss/ hesitation pop up recently. No other signs really, but I am paranoid because when I bought it (used, its almost 25 yrs old) the mechanic did warn that it looks kinda worn and keep an eye on signs of gasket failure. That was 2.5 yrs ago? I actually fixed some power loss today- a while back I broke a hard vac hose into several pieces and used gorilla tape to put it back together....realized the freak heat wave melted my tape cocoon and the pieces of hose were just sorta sloshing around in it lol. Got some real hose connectors and high temp tape to be safe and it runs much better now. Still paranoid about the head gasket. I know its coming for me. If my cap leakage doesnt resolve after bleeding coolant I am considering using some gasket sealer just in case.
A vacuum leak will definitely cause hesitation, but in some cases it should clear up somewhat when you kick it in the guts and go wide open throttle. A new vacuum line would be best. It's (probably) not expensive either. But vacuum leaks will definitely cause driveability concerns.
As for pushing coolant out into the overflow tank, this is a classic sign of head gasket failure, I'm afraid. The Commodores I have, while not being known for head gasket failure (thanks to the bulletproof Buick 3800 they used), will push coolant out when it gets hot and then suck it back in when it cools down, which makes catching it in the act a bastard of a thing to do because it'll show normal coolant levels when you check it. Something you can do is if the radiator hoses are absolutely rock hard when it's hot, that's a sign of over-pressure and the radiator cap will dutifully vent excess pressure into the overflow tank (if your car has one. It'll vent it to the ground if it doesn't.) and that's a classic sign of head gasket failure. Normal radiator hoses should be firm when hot, but not rock hard. It's hard to explain, you can only really feel it.
It doesn't need to have oil/coolant contamination, or overheat; it is possible for it to fail to a coolant jacket in the head and the only obvious symptom you get is it pisses coolant out into the tank or on to the floor. Once this happens enough then it *will* start to overheat due to the loss of coolant.
The gold standard test for head gasket failure is a chemical test. You have a tube that goes into where the radiator cap lives, filled with a liquid. You suck air up into this liquid with the engine running and if it changes colour, that indicates the presence of combustion gasses which confirms the failure of the head gasket. The test is not expensive or difficult. It takes literally five minutes. But that will tell you if your head gasket is blown.
Hope this helps.
