Eight car noises you should never ignore

Linda Melone

Turning up the radio to drown out your car's noises can cost you money in a couple of ways. Skipping maintenance to fix those noises can result in a crash, which can raise your insurance rates when you have to file a claim.

Plus, ignoring your car's warning sounds for too long could result in heftier repair bills than you if you'd taken your car to the repair shop right away.

"It's important to keep up any and all vehicle maintenance to ensure you have a vehicle that operates properly," says Erin Lewis, assistant vice president insurance services at Foundation Financial Group in Jacksonville, Fla.

Listen to your car if you hear hissing or sizzling under the hood.

Not all maintenance issues give you a noisy warning, however. Worn-out tires, for example, may not give you a clue that anything's wrong until they blow out. "Always be aware of the condition of your tires to be sure that they are adequate for your driving conditions," Lewis says.

In addition:

• Be sure head lights, tail lights, brake lights and turn signals operate properly. • Replace windshield wipers when they're worn out. • Know the condition of your brakes. • Repair any damaged glass that obstructs your view. Can you hear me now?

Listen to your car when it makes noises. "It could be trying to tell you something," says Victor Broski, service manager at Newport Motorsports in Costa Mesa, Calif.

Here are the top eight car noises you should always listen to. (Repair costs listed here can vary according to the type of car, the severity of the problem and any related damage).

1. Grinding manual transmission when shifting.

Spend money to fix it or shift slower, which lets you drive the car longer and delay this expensive repair. It’s more than likely a synchro in the transmission, a part that "synchronizes" the different gears spinning at different speeds.

How serious? Moderate; no time pressure, but get it fixed within a year. Estimated cost to repair: Thousands of dollars.

2. Hissing or sizzling under the hood.

This probably is caused by a leak in the cooling system, which is under pressure. It's usually accompanied by steam or coolant leaking or spraying -- a warning sign before it runs out of coolant and overheats. Pull over as soon as possible. Use extreme caution when lifting the hood, as hot steam or coolant may burn you.

How serious? Very. Estimated cost to repair: $500 (less if it's just a radiator hose and not the radiator).

3. Engine knocking.

The deeper (and louder) the sound is, the more expensive it'll be to repair. This may be a rocker arm (a lever within the engine), piston (transfers force from expanding gas in the cylinder to the crankshaft) or rod bearing. Pull over as soon as possible.

How serious? Very. Estimated cost to repair: $2,000 to $10,000 or more (depending on car and extent of damage).

4. Explosive bang.

Diagnosis: Probably a tire blow-out. You'll experience erratic steering or wandering. Prepare to pull over immediately. Make sure you have air in your spare tire.

How serious? Very. Estimated cost to repair: Cost of a tire, plus mounting and balancing (roughly $18).

5. Rattling from beneath the vehicle.

This may be the catalytic converter breaking apart on the inside. Sometimes the loose part gets stuck and the rattle temporarily stops. Or the sheet metal around the exhaust rattles. Or the exhaust pipe has lost a muffler hanger and the exhaust pipe is hitting something under the car.

How serious? Not very, unless you need an emissions inspection. Estimated cost to repair: $400 to $1,500 (exotic cars may be higher).

6. Roaring that increases with acceleration.

This could be caused by a timing belt roller or a serpentine belt roller. You won’t be able to tell the difference, but your mechanic will. There's a big difference in potential damage to your wallet, depending on the belt roller doing the damage. A serpentine belt repair costs $200 to $300, while the timing belt causes more extensive engine damage that could cost $4,000 or more. Replace the roller on schedule if not before, and you'll avoid the problem altogether.

How serious? Medium to very. Estimated cost to repair: $200 to $4,000.

7. Squealing wheels when applying brakes.

Some cars have a metal tab that rubs the brake rotor when the brake pads get low. It’s a warning that the brake pads are getting thin. Or it's brake pad material itself.

How serious? Medium, but get it done within 500 miles. Estimated cost to repair: $150.

8. Scraping or grinding when applying brakes.

You didn’t pay attention to the squeal. This usually means you've worn through the brake pad material, you're now hearing a metal-on-metal noise. The brake job just tripled in price. How serious? Very. Estimated cost to repair: $450 and up.

Free Insurance Quotes