2009 Holden Cruze Problem with car

Start with the Check Engine light. That means the Engine Computer detected a problem, set a diagnostic fault code, and turned the light on to tell you. Your mechanic will connect a scanner to read the code, then give you an idea of where he needs to start looking. The codes never say to replace parts or that they're bad. They just indicate the circuit or system that needs further diagnosis.

There's no way to verify a leaking cylinder head gasket by just guessing. There would also be additional symptoms. The shaking is a major clue something is wrong, even without the Check Engine light, and it should never be ignored. You could have nothing more wrong than worn spark plugs and wires. Since you likely don't know the recent maintenance history, that is the logical place to start. There are even diagnostic fault codes that can tell you which cylinders are misfiring.

As for cost, we don't get involved with that here because there's way too many variables. We don't even know what's wrong yet.

I understand your concern, but I taught Automotive Technology for nine years, and three of my top students were girls. The guys had a lot of respect for them.

I will never defend a dishonest shop or mechanic, but way too often they get blamed for selling unneeded parts or services because people don't understand their cars and what it takes to diagnose their problems. Some mechanics have your best interest at heart and want to do everything possible to insure the car is repaired right the first time. That means replacing questionable parts that MIGHT still be okay, ... But do you want to risk breaking down in the country on a dark Saturday night? They don't want to risk their reputation either. Some mechanics have your wallet in mind when they try to reuse some parts that probably should be replaced. They're gambling those parts won't fail, and you'll appreciate them saving you some money. If one of those parts does fail soon after the initial repair, you assume they don't know what they're doing, and that isn't fair either.

The best way to approach any repair is to look at the mechanic as your advocate, not your adversary. There is nothing in it for him to not fix your car correctly. He knows you'll lose confidence in the shop and never come back. The biggest thing you can do is to provide as much useful information and detail as possible so he doesn't have to take the time to learn them himself. Also understand there's many problems that don't act up all the time. Those fault codes can help, but he really needs to have the problem occurring to troubleshoot it. That often means leaving the car for a day or two.

If you don't really trust the diagnosis you're given, get a second opinion from a different shop, but don't tell that second mechanic where you just were or what their diagnosis was. If they're friends with that first shop, they'll be inclined to just agree with their diagnosis without really investigating thoroughly. If the first mechanic was wrong, the second one will be too. If the two shops don't like each other, the second mechanic could be tempted to "find" a different cause, to make the first shop look bad. With no such information to cloud their diagnosis, it stands a better chance of being right.

Eventually you'll build a trusting relationship with one shop. They put more effort into keeping a repeat customer happy so they keep on coming back in the future. They'll learn your car's history and your maintenance habits, so they'll be better equipped to know how to keep your car running at its best.

Also keep in mind that cars today are WAY unnecessarily over-complicated and full of unnecessary technology. Most guys also know very little about these machines we trust to get us back home, so the fear isn't in being a girl; it's in not having the years of continuing training to understand all the things that commonly go wrong with them.