When you drive, your car makes plenty of noises that you have probably learned to ignore because the sounds are just part of the normal operation of your vehicle. However, when you start to notice unusual loud noises coming from your engine when you drive, you need to figure out if the sounds are the signs of a serious problem. The following guide describes sounds that indicate your car is in need of immediate repair.

High-pitched Squeals

Squealing noises when you drive, brake and shut off your engine are unpleasant to hear and can be a sign of a few issues.

When your car's serpentine belt is loose, cracked, frayed or slipping, it produces a high-pitched squeal. The belt connects several engine accessories including the alternator, water pump, power steering and other devices. The squealing also occurs if one of the devices becomes misaligned.

Getting your serpentine belt replaced is a relatively inexpensive repair. Take care of a damaged serpentine belt as soon as possible to avoid having your engine overheat because your water pump and other engine parts are not working properly.

Your car will also squeal if your car's brake pads, rotors and shoes are dirty or badly worn. The noise will occur when you press your brake pedal to slow down. For safety reasons, you should have those brake accessories fixed immediately to avoid getting into an accident because your car failed to stop properly.

Knocking Sounds

When you hear noises coming from your engine like there is someone under the hood trying to get out using a hammer, stop driving as soon as you can. The loud knocking sounds could be a sign that you are using the wrong type of fuel or spark plugs.

Make sure that the fuel you use is the right octane rating for your vehicle. This information should be in your owner's manual. Low quality fuel can lead to increased temperatures in your engine's combustion chambers. Switching to a higher octane fuel may solve the knocking problem.

If you have the wrong type of spark plugs installed, the devices will malfunction and cause loud noises. Instead of trying to replace the spark plugs with cheap devices you purchase from an auto parts store, let a certified mechanic complete the task for you to make sure you have the right product installed in your vehicle.

Whistling

Whistling sounds that come from under your hood generally indicate a vacuum leak in your car's intake system. Your mechanic can determine the exact source of the leak.

If you hear a whistling noise from inside the car, it could be something as simple as worn weatherstripping around windows or your sun roof. If you locate the source of the whistling and feel up to performing a DIY project, you can purchase weather stripping and replace the material on your own.

Hissing

It is unsettling to hear hissing noises when you drive and when you turn your engine off. The cause of the sounds may indicate that your car is leaking coolant that falls onto heated engine parts. You should have a mechanic replace any faulty lines that are leaking fluid.

If you fail to repair lines that carry coolant, your car will overheat. Your car's temperature warning light will indicate an overheated engine. If you ignore the warning light, you risk overheating your engine to an unsafe level. Your car will start to emit steam that rises from your hood as you drive. If this happens, stop driving and let your car cool down.

If you want to check for signs of leaked coolant, open the hood and look around the radiator and heater hoses. However, do not open the caps for the coolant or radiator until the car is completely cool. If possible, get your car towed to a mechanic to fix the leak.

For more information and tips, contact a local auto shop or visit sites like http://www.soundsideauto.com.