Consumer Reports: Can you trust your car mechanic?

It's a common experience: You bring your car in for routine maintenance or a recall service, and the mechanic tells you there are much bigger problems that need attention. But do they really?

Consumer Reports says be skeptical when searching for a good car mechanic. Here's advice on how to avoid unnecessary and expensive repairs.

Lisa Leone says she is no expert when it comes to cars. So when her car started to shudder, she brought it to her dealer's mechanic and was told some scary news.

"I had done damage to this major part in the car, and it was probably going to cost me $4,000 dollars in the end," she recalled.

Suspicious, she brought the car to another mechanic for a second opinion. In the end, it turned out that a simple reboot of the car's computer solved the problem.

"Part of the reason mechanics may pressure or mislead you is because cars are more reliable these days, and fewer repairs mean lower profits for those garages," said Mark Rechtin, Chief Cars Editor at Consumer Reports.

Some mechanics may even lie about what they find under the hood when you bring your vehicle into the shop.

Some common scams include:

- Faking a leak: Putting drops of coolant on your engine to mimic a broken radiator.

- Recommending an unneeded full brake replacement with rotors and calipers, when simply replacing the brake pads and resurfacing the rotors will do.

- Calling for a transmission flush, which under certain circumstances can actually cause damage.

"Also check your owner's manual for your car's maintenance schedule, especially if you suspect that a mechanic is trying to trick you by suggesting you replace an expensive piece, like a timing belt, before it's really necessary," said Mark.

For any repair, be sure to get an estimate in writing. And if you still question it, seek out a second opinion from a trusted mechanic.

And be on guard if you get a recall notice. Some unscrupulous dealers may refuse to do the free fix unless you agree to other expensive repairs or maintenance.

Refusing to do a recall service until you have other unrelated repairs done is unethical and against Department of Transportation regulations.

Dealers who do so should be reported right away to the government. Go to safercar.gov and click on "File a complaint."