What's that Funny Sound Coming from Under My Car?

It happens all the time. You're in the car and suddenly, "fwuup, fwuup, fwuup, fwuup". What the heck? Is it serious? Should I stop, or can I get where I'm going, and worry about it later?

Internet diagnosis is no substitute for having a real, live mechanic look at your car, but I can give you a few quick ideas to let you make a more informed choice about stopping or driving on when you hear an unusual noise. It may also help you to sound like you know what you're talking about when you DO call the mechanic. This can help prevent repair rip-offs.

Funny sound at the back of the car.

From the rear, you get sounds related to TIRES, BRAKES, EXHAUST, FUEL PUMP, and sometimes (if the car is rear-wheel drive) from the DIFFERENTIAL (that big lump where axles from both rear wheels meet). Rhythmic "fwuup-fwuup" sounds that happen while the car is moving are usually tire related. (Look for lumps or exposed chords, and replace the tire if you find them.) Rhythmic or continual squealing ("screeeeeeeach!") sounds are often brakes. While you don't want brakes to go unchecked for long, you don't need to panic right away.

Some brake repair tips.

Look at your rear wheels. Can you see a flat silver disc when looking through the spokes of the wheel, or holes in the wheel cover? If so, you have DISC BRAKES. Squealing disc brakes are a sign that they're wearing out. Manufacturers put a "wear bar" into your brake pads, and as they wear down, this bar contacts the disc, and squeals. It's annoying, but not dangerous yet. If you see deep grooves on the disc, it MAY be dangerous. If the sound from the rear of the car is more of a "graaaawwwtch..", that is likely metal-on-metal contact, and it means your brake pads (the part of the brake that squeezes the disc to slow you down) are GONE, or there is some foreign matter (like gravel, or a nail) wedged between the pad and disc. This is potentially dangerous, and should persuade you to find a brake shop quickly.

Adjusting drum brakes.