When all is well, a car is a smooth-running machine. But as soon as you start hearing unexpected noises or smelling unwanted scents, you should pay attention –– because that’s your car sending you a warning of what is to come.
“Our cars have gotten very good at kind of self-adjusting for problems, which means we don’t always know right off the bat when there’s something wrong… But that means that by the time you’re smelling something or hearing something… or you’re seeing drips on the driveway, it’s already gotten bad,” said Bogi Lateiner, a master automotive technician and the owner of Girl Gang Garage, a network that provides hands-on training for women in the trades.
The following are the most common smells and sounds car mechanics say we should never ignore:
- Burning Oil Smells. Burning oil smells have an industrial “factory kind of smell,” and they can result in a number of different potential risks, Lateiner said. If you’re smelling this inside the cab or under your car’s hood, it likely means you’ve got oil leaking out of something like your engine or power steering and then leaking onto something hot, Lateiner said.
Oil leaks are bad for two main reasons: For one, it means oil, which is the lifeblood of your car, is not where it’s supposed to be, and is not “keeping it lubricated, keeping it from getting damaged,” Lateiner explained. It also likely means that oil was leaking out onto something hot and burning off, which can cause a fire.
There can also be visible signs of an oil leak. Noticing what color the leak is can help your mechanic diagnose the problem. If the substance is reddish, for example, the oil leak likely is coming from your power steering system or transmission system, while engine oil is generally a brown color, Lateiner said.
- Burning Rubber Smells. Chad Cantrell, a mechanic at Forest Brook Automotive, said you might smell this when there are brake caliper issues. Brake calipers are a hydraulic clamping mechanism that squeeze the brake pads against the rotors to slow your car down when you hit the brake pedal. When they are failing, they might lock up, which could lock your wheel up and cause your tire to grab the asphalt because it’s turning improperly. Cantrell recommends taking your car to the shop or you’ll to tear up your tire and the car won’t drive straight.
- Sickly Sweet Smells. A common complaint is a “sickeningly sweet, acidic” or “hot syrup smell” coming from the vents or outside the car, Lateiner said. It generally means that your coolant ― which keeps your car running at ideal temperatures ― is leaking and getting onto something hot. Coolant is not flammable, so you do not have a fire risk, but your bill will get more expensive the longer you wait. If you run out of coolant and your engine overheats, repairing that “can cost thousands and thousands of dollars to fix,” Lateiner said. “A coolant leak is relatively inexpensive to fix. But the effects of ignoring it [can get] expensive.”
- Burning Plastic Smells. A burning plastic smell could just mean you drove over a plastic bag and it got caught in your exhaust, which is not a big deal because it should just burn off, Lateiner said. But it could mean a cable or a wire has come loose and is touching your exhaust. You do not want to neglect an electrical issue, which is why you should bring the car in ASAP for inspection, just in case.
- Moldy Smells. If you smell a “dirty sock” odor in your car, that is most likely coming from your cabin filter due to mildew in your A/C box underneath your dashboard, Lateiner said. Cabin filters can get “really gross, especially if you’re in a humid climate.”
A quick car lesson: Often located behind your glovebox, a cabin filter is the filter for the air that you breathe inside your car, while your air filter is for your engine and prevents dirt and debris from reaching it.
- Rotten Egg Smells. If you’re smelling sulfur out of your exhaust, it is a sign you have a bad or aging catalytic converter, which is responsible for cleaning your car’s exhaust system. Lateiner said this smell will typically be accompanied by other alarm bells like a “check engine” light or a rough acceleration. It could also mean your catalytic converter just got stolen; they contain rare metals that thieves target.
- Brake Noises. Because brakes are essential to stopping or starting your car, they should never be ignored. Some squeals or chirps can be an easy fix and are not hazards. A high-pitched brake sound that you only hear when you stop your car in the morning might just be dealing with a little bit of surface rust on your rotors,” which are inside of each wheel and help your car safely stop when you press the brake pedal. But some might be a bigger hazard if left ignored.
“If you hear like a machine gun ‘pa-pa-pa’ kind of sound when turning, that could be a CV axle that’s going bad and that could leave you stranded if it gets worse,” Lateiner said. A grinding noise from your brakes is the “worst” noise to hear, because it likely means your problem has gotten worse and “metal-to-metal does not stop your car very well,” Lateiner said. If you keep ignoring a grinding brake noise, you will eventually “lose all brake and your pedal will go straight to the floor.”
- Clunking Noises. Clunking noises could be due to your bushings, ball joint or sway bar going bad, Cantrell said. Bushings absorb car vibrations and noises, while a car’s flexible ball-and-socket joints help your suspension move up and down as your car travels over bumps. Sway bars are U-shaped stabilizers that keep your car level over fast corners. These are all vital car parts for keeping your vehicle moving forward smoothly.
“Older cars will start making clunks and snaps and pops and creaks and groans… and it’s generally because one of the joints, one of the bushings or one of the things [where] its job is to allow movement, but not too much movement, has gotten worn and is allowing the wrong kind of movement,” Lateiner explained. Ignore these clunks at your own peril. Cantrell says if a car has broken ball joints “the whole car will fall like… the fender will be on top of the tire.”
- Rattling Noises. Cantrell said rattling noises could be a small problem like an “exhaust plate or a bracket that has gotten loose, but they could also be a larger issue like a timing chain tensioner problem.” Timing belts and timing chains keep your engine synchronizing properly, so your car’s pistons and valves operate correctly. When these car parts “go bad, it can lock up your engine,” he said
How to help your mechanic diagnose what’s wrong
You may not be able to speak car like a mechanic, but if you drive your vehicle regularly, you know it better than anybody else, and you should listen to your intuition that is telling you something is not right. When you bring your car to be repaired, go beyond saying something sounds or smells “funny,” and be as specific as you can about when and where you are hearing or smelling what is concerning you. “If you can record the sound and play it for us and make the noise for us… it really does help us figure out what it is,” Lateiner suggested. “It saves time, which translates to saving you money the more you can point us in the right direction.”
Source: HuffPost
