10 Car Noises to Be Concerned About

Craig Cole
by Craig Cole

With a twist of the key or poke of its start button your vehicle’s engine should fire up with the urgency of a physician responding to a code blue.

Of course it should also idle as smoothly as a sewing machine running a line of chain stitches. If this isn’t the case you ought to take note because something serious could be awry.

The same is true for the rest of your car or truck. It should operate as silently as a napping kitten and feel smoother than satin underwear. Modern vehicles are engineering marvels built to exacting standards, but as with anything crafted by man, things will go wrong and often in spectacular fashion. If for some reason your car is making uncouth noises here’s a small sample of what could be going on.


1. Hissing

Sure, there might be a bundle of rattle snakes living under the hood but if your car or truck’s engine makes a hissing sound it could also be an indication of a leak, either in the cooling system or a vacuum line. If it’s the former overheating is a concern, the latter, drivability and fuel-economy issues could result. A trip to the mechanic is in order.


2. Clunking

If your vehicle clunks while driving over bumps or pot holes something is definitely out of order.

Bad ball joints, worn control-arm bushings or faulty stabilizer link-pins can cause uncivilized sounds, but other chassis components could be to blame as well. Even a loose exhaust system can flop round and make percussive noises.


3. Porcine Squealing

If your car’s engine is making a shrieking sound it could be an issue with the serpentine belt. Either the rubber has gotten old and brittle or the tensioner could be failing. If the latter is to blame the belt may not have the appropriate pressure applied to it, causing slippage and ultimately ill-mannered commotion. Fortunately this repair should be relatively simple and inexpensive so there’s no excuse for putting this off. Get it taken care of before the belt snaps or pops off when you’re driving home at 2:00 in the morning during an ice storm, because, you know, that’s when it would happen.


4. Metallic Screeching or Guttural Groaning

If there’s a screeching sound when you apply the brakes it’s a good chance the pads have reached the end of their useful lives. Many are engineered with small metal tabs that rub against the rotor when the friction material is worn away to a certain point. The squealing sound is an indication that it’s time for a brake job.

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If you put off this necessary maintenance for too long the noise could progress to a demonic growling. It occurs when the pads have been worn down all the way to the rivets or steel backing plates, a very bad situation. If a similar but less harsh rumbling noise happens all the time while moving it can signal a bad wheel bearing.


5. Clickety-Clack

If your front-wheel-drive vehicle sounds like an Amtrak train while moving at low speed with the wheels turned it could be an indication that the constant velocity or CV joints are failing. They’re located on the ends of the drive axles.

And these are some of the hardest working parts in a car. They send power the wheels and deal with vertical inputs from the road all while allowing you to steer. There’s a lot going on in a small area so cut ‘em some slack. A similar noise coming from the back of a rear-drive vehicle can be an indication of a bad universal joint.


6. Growling or Moaning

Also during turns, if your vehicle starts growling like a starved lioness it may be an indication that the power-steering pump is not long for this world. And you may not be either if you ignore this issue.

True, many new cars and trucks are equipped with electrically assisted steering, arrangements that often negate the need for a traditional hydraulic setup. Still, lots of vehicles just a few years old are outfitted with such systems and if they’re starting to go south it’s best to get this issue taken care of before you lose boost and can’t turn properly.


7. Under-Hood Percussion

If you hear a rattling, pinging or hammering sound beware. This racket is associated with three separate but related combustion problems: detonation, pre-ignition and spark knock, all of which can be extremely harmful. They often occur during acceleration or while the engine is under load.

Essentially what’s happening when one of these problems manifests is abnormal ignition. Instead of an even firing of the air-fuel mixture within an engine’s combustion chamber there are multiple flame fronts. When these pressure waves collide they produce a pinging or clattering sound. Detonation is the perhaps the most severe issue and can literally destroy pistons.

Running higher octane gasoline, changing the air-fuel mixture, retarding ignition timing or de-carbonizing combustion chambers can rectify these problems.


8. Clattering or Knocking

If your vehicle’s engine makes a clattering or knocking noise that increases with RPM it could be in serious trouble. The former, which is usually a “tap-tap-tap” sound, can be indicative of a lifter that isn’t pumping up or a sign that the valve clearances need to be adjusted. This isn’t necessarily a fatal issue, but it’s one you should have checked out by a qualified professional sooner than later.

However, if the noise is deep and hammering get out your wallet. This can point to a bad rod bearing, which is a serious job to replace. But wait, it gets worse! It can also indicate that your engine has spun a bearing, something that requires pulling the entire lower end — and likely the whole powertrain — to address.


9. Cap’n Crunch

If you drive something with a manual transmission (thank you!) and you’re starting to hear a crunching sound while changing gears it can be a symptom of several different problems, ones usually associated with high mileage.

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For starters, gear grinding can be indicative of a worn out synchronizer, the transmission component that enables easy shifting from one ratio to another. If these are dilapidated they will not be able to equalize the speeds of the different shafts inside the transmission and the dog clutches will grind. Likewise, a dragging clutch could be the culprit, one that’s not fully disengaging when the pedal is depressed. Both of these issues often require extensive service work to correct.


10. Howling

If your rear-wheel-drive car or truck is making a howling sound that seems to be coming from out back, this can be a symptom of a problem with the differential. A variety of noises can be produced by one of these components in different driving situations, from acceleration to deceleration to steady-state motoring. Pinion preload, worn gears or bad bearings can cause these noises.

Recent Updates

November 8th, 2021: updated text in Clunking Sounds for accuracy. Updated the Metallic Screeching or Guttural Groaning section for accuracy. Updated links to new articles.

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Craig Cole
Craig Cole

Born and raised in metro Detroit, Craig was steeped in mechanics from childhood. He feels as much at home with a wrench or welding gun in his hand as he does behind the wheel or in front of a camera. Putting his Bachelor's Degree in Journalism to good use, he's always pumping out videos, reviews, and features for AutoGuide.com. When the workday is over, he can be found out driving his fully restored 1936 Ford V8 sedan. Craig has covered the automotive industry full time for more than 10 years and is a member of the Automotive Press Association (APA) and Midwest Automotive Media Association (MAMA).

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  • Anna Anna on Jun 21, 2023

    My 2007 jeep Patriot 2.4 liter fwd started making a loud industrial like sound recently. It gets worse when I accelerate and pulling hills and I haven't drove it since I heard that sound.

  • Marcia Marcia on Sep 28, 2023

    My issue is with a 2008 Mazda3 hatchback with 147,000 miles. I drive very few miles per month/year, maybe 25 miles a month so it's been a pretty good car. The other day my engine light came on so I checked all the usual, topped off any needed fluids, checked the gas cap then removed the negative battery cable & turned off the dash engine light. All was well after making a test drive. Today I started out to the grocery store & at low speed (30-35mph) I heard a loud single clunking noise from under the car followed by the engine light coming back on. I immediately turned around & went home. The clunk occurred again when I slowed down to turn around in a driveway. Any thoughts or input would be greatly appreciated.

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