What your car is trying to tell you -- Page 2

Knocking in the front of car
Do you hear knocking when you accelerate from a stop or when you brake? "That's really a warning that there is something seriously wrong in the suspension or steering," says Cerullo. "That's got to be repaired. That wear could cause something to pop out or cause accelerated wear to the rest of the steering or the tires."

Loud knocking from the engine       Click here to listen
"The key word is 'loud,'" says Sclar. "Immediately pull to the side of road and call for road service," she says. While it could be something minor, Sclar notes that it could also be a loose bearing or a faulty piston. If that's the case, she says, continued driving "can destroy your whole engine."

Pinging from the engine
Does it sound like someone's banging on the engine with a hammer when you step on the gas? "That happens most often on modern cars when there's a problem with the timing in the engine," says Cerullo.

It could just be cheap gas. But if you tank up with premium and still have a problem, you could need a tune-up, says Cerullo. "It certainly should be brought to the attention of a technician," he says.

Possible culprits include a defective exhaust-gas recirculation valve or engine overheating. "It's a wake-up call that something needs to be done," he says. But you don't need to worry if you only hear it when you're putting the car through a one-time stress situation, such as pulling a heavy trailer uphill on a hot day.

Grinding from the brakes
"If you step on the brakes and hear a grinding, that's serious and needs to be attended to immediately," Cerullo says. The most likely cause is worn brake pads.

Squealing from brakes
"It may not be serious, especially if you're fairly sure your brakes have been checked recently or are new," says Cerullo. "Something should be done, but it's not as urgent as the grinding noise."

Squealing from the tires       Click here to listen
If your car tires squeal when you turn, that "will indicate problems with wheel alignment," Cerullo says. And it's definitely something to check. "It could cause tire failure," he says.

Thumping or bumping from a tire       Click here to listen
Congratulations! You've got a flat.

Engine runs after the car is off
It's called dieseling, says Sclar. "You've either got too-high octane fuel or you might have bad gasoline," she says. "Or sometimes your idle speed is set too high." If a new tank of gas from a different station doesn't clear up the problem, visit your garage.

Crackling sound after you shut off the car
No problem, says Cerullo. As soon as you turn off the engine the catalytic converter immediately begins to cool, causing a crackling sound, he says. "That you don't have to worry about."

Shimmy, shimmy, shake
OK, you've been a good listener, got the car into the shop early and repaired the problem with minimal financial damage. But you also need to pay attention to your auto's nonverbal messages.

Do you feel a vibration or shimmy in the steering wheel? This could be a couple of things, says Cerullo.

First, it's possible that the wheel balance weights have come off and the tires are out of balance. One clue: It's OK at some speeds, but not at others. Maintain a speed that minimizes the shimmy and get it checked out. "Ignoring it causes premature tire wear," Cerullo says.

It also could be caused by worn shocks, MacPherson struts or steering linkage, he says. If the problem shows up after you hit a bump, as opposed to a shimmy that shows up at a particular speed, "that's usually wear," he says.

Hitting the brakes should stabilize it, but get it checked out pronto. "It could cause steering failure," Cerullo says.

Bottom line: Listen to your "talkative" auto in every way that it tries to communicate. In addition to the safety component, understanding your car's language can save you money. Sclar learned that costly lesson before she researched and wrote her book.

She got stuck with over $200 worth of radiator work on a new car that was singing. The real culprit was a $4 radiator cap.

Dana Dratch is a freelance writer based in Atlanta.