We spend so much time in our cars that we get used to things, like the steady sound of the engine at normal operating speed. When something sounds different, we know right away. It's a good thing because strange sounds can signal something going wrong inside the engine. You shouldn't ignore the five noises: popping, knocking, hissing, squealing, and rumbling.
- Popping: a leaking or failing exhaust system can lead to popping noises, like small backfires. When the exhaust leaks the engine performance decreases because gasses that should go out the tailpipe are backing up into the combustion chambers. They should only have gas and air at a precise mixture for peak performance.
- Knocking: If you've ever stepped on the gas and heard your engine knock as your car is slow to react, you'll know the knocking sound. This means your engine systems aren't working properly. A leaking exhaust and a clogged air filter can both cause engine knocks.
- Hissing: The most common cause of hissing is a leaking coolant system hose that has cracked and needs replacing. Those hoses can blow after or during the hissing if a car overheats. Oil leaking onto the engine block can sometimes hiss. You'll smell burning oil along with the hissing.
- Squealing: If your brakes need new pads, you'll know because they start squealing. Belts sometimes squeal if they are wearing out or need adjusting. Older cars could have two or three belts running different accessories. Newer cars have one belt running several accessories.
- Rumbling: If you ever hear low rumbling, your fan belt might be rubbing a hose. Failing exhaust systems can also cause rumbling near the catalytic converter.
Getting to the source of the squealing quickly can save hundreds of dollars in repair costs. Cars usually have sensors that trigger lights inside the dashboard. These lights should never be ignored. Experience is the best way to understand the sounds coming from your car. The best thing you can do when you hear a strange sound is don't Ignore it. Even if the car still runs well the sound could be the start a serious mechanical issue. Chances are it's a quick fix if you catch it early.