Common signs of car problems

May 10, 2020

One of the most common mistakes people make is relying on technology too much: if there are no warning lights, it means that the car is OK, right? No, it doesn't. It only means that the car has not detected faults that are pre-programmed in its computer. If you feel that something is wrong with your car, you are smarter than any computer, don't rely on warning lights; have it checked out.

You can save a lot of money and keep your car safe if you can recognize early signs of car problems. We have seen many situations where expensive repairs were avoided because problems were caught early.

Gear oil leak

Gear oil leak from the transfer case (PTU).

For example, check this photo, the owner of this SUV noticed a bad sulphur smell coming from under the car. He also saw a couple of drops of fluid on his driveway. When he brought the vehicle to have it checked, it was the transfer case (known as PTU) fluid leaking. The shop was able to save the PTU by repairing the leak and changing the fluid in it. It saved the owner over $1,000 that he would have to pay to replace the PTU if he continued driving.

Your car needs to be inspected by a qualified mechanic in a repair shop where it can be lifted on the hoist at least once a year or sooner if required in the maintenance schedule. It also needs to be checked out if you feel there is something wrong with it. It's impossible to mention all possible signs of car problems, so we listed only a few common signs. The owner's manual for your vehicle can also provide some answers.

1. Abnormal noises

Separated ball joint

This ball joint has separated while driving

It's one thing when your glasses are rattling in the overhead sunglasses holder, but if something makes creaking, rattling knocking or other noise when you drive, how do you know if it's not coming from loose lug nuts (nuts that hold the wheels) or a ball joint that is about to break off or brakes that are completely worn out? We have seen this happen, see the photos. For your safety, if your car makes any abnormal noise, take it to a repair shop to investigate. If you suspect the noise is coming from the wheels, pull over when safe and check if the lug nuts are tight. The owner's manual has the instructions. Here are a few common examples:

  • Squeaking or grinding from the brakes: could be anything from completely worn-out brakes to a sticky brake caliper or simply brakes that need to be serviced.
  • Engine sounds louder: An oil level could be low, (see how to check it) or the air filter
    Completely worn out brakes

    The arrow points where the brake pad should have been. It h completely worn out and fell off.

    box might not be closed properly or there is an exhaust leak, or something else.
  • Ticking noise from the top of the engine: Common culprits are worn out rocker arms (e.g. in Pentastar V6) or a collapsed hydraulic valve lifters (lash adjuster) or other parts of the valve train mechanism. A low oil level or very dirty oil can also cause valvetrain or timing chain noises.
  • Squealing or chirping noises from the engine compartment: A worn-out serpentine belt can make noises like this, especially in wet weather. A bad belt tensioner is another possibility.
  • Humming noise when driving: A bad wheel bearing can cause a humming noise that becomes louder with speed or when changing lanes. Cupped tires can also cause a humming or rumbling noise.
  • Rattling, knocking or creaking noises coming from the steering, front end or rear suspension: there are so many possible causes, and many of them could be safety related. Have the vehicle checked out ASAP.
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2. Warning lights on the dash

Check Engine - Service Engine Soon light

Check Engine or Malfunction indicator light (MIL)

If any warning light comes on, check what it means in the owner's manual. Some of the most common warning lights are:

  • Check Engine light: it might come on if the gas tank cap is not closed tight or for other emissions-related problems. It also might come on for many more serious problems, for example, when your engine is very low on oil. You won't know whether it's a serious problem or not until a mechanic scans the vehicle computer, reads trouble codes and diagnoses it. Read more: Check Engine light: what to check, common problems, repair options.
  • Low tire pressure warning light: it means just that - tire pressure must be checked. It could be that one of the tires picked up a nail or is simply low on air, or something is wrong with the tire pressure (TPMS) system or sensor. Any local repair shop can help. Many gas stations have an air pump that you can use to check the tire pressure.
  • Battery light: a warning light that looks like a car battery typically means that either your engine is not running or the charging system doesn't work. The main component of the charging system is an alternator. Read more about the alternator.
  • ABS light: it means that something is wrong with the antilock braking system. A mechanic must scan the ABS computer and read the trouble code that will help diagnosing the problem. Examples of ABS problems are a bad wheel speed sensor, cracked or contaminated wheel speed sensor tone ring, loose wheel bearing, faulty ABS module.

3. Steering wheel shakes when braking at high speed

This often points to warped or rusted brake rotors (usually front rotors), but could be a few other things, for example, something with wheels or tires or a bad tie rod or steering damper. In either case, it must be checked. If after the inspection, the mechanic confirms bad brake rotors, they might need to be machined or replaced.

4. Vibrations

Various problems with wheels and tires are the most common

Damaged tire

This damaged tire was causing a vibration; it's unsafe to drive.

source of vibration that is felt between 50 and 65 mph (80-105 km/hour) and doesn't change whether accelerating or decelerating but only changes with speed. For example, see the photo. If you feel that it's a problem with your tires, but the repair shop has already tried re-balancing your tires and the vibration is still there, ask for Road Force balancing; it's more advanced. Problems with the driveline and engine mounts are another common source of vibrations An engine that misfires will also cause a vibration.

5. Change in the vehicle's performance

Any difference in the way the vehicle drives or feels should alert you. Does the brake pedal seem to go down too far or is it too stiff? Definitely have it checked out. Does the transmission shift differently? If you notice a jolt or the transmission shifts harshly, there could be a simple software update that might improve shifting quality and prevent other problems. The transmission fluid must be checked too. Does the engine hesitate on acceleration? Does it lack power? Does it run rough at idle? It might need a tune-up or there is some developing problem that has not yet resulted in the Check Engine light.

6. Signs of overheating


Overheating can result in expensive repairs.

Overheating is bad not only for the engine but for any mechanical device. If you notice the engine temperature rising above normal, have the cooling system checked. If the message "Transmission Overheated" comes on, it's good to know what caused it. Many transmission problems are also caused by overheating. Many owners install additional transmission fluid coolers to prevent overheating the transmission when towing. If one of the wheels appear hotter than others, have the brakes checked.

7. The steering is off-center or the car pulls to the side

If when driving straight, the steering wheel is off-center, or the vehicle pulls to one side, have the wheel alignment checked. Often this happens after hitting a large pothole. Tires and tire pressure, as well as brakes, must be checked too. Normally, when you drive straight on a level road, the steering wheel should be centered and the car should hold the straight direction well. The car may pull slightly towards the slopped side of the road, this is normal.

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8. Uneven tire wear, damage to the tires

Damaged tire

This tire is unsafe to drive.

Watch out for uneven tire wear or visible damage. If tires wear unevenly, it indicates possible problems with the wheel alignment, steering or suspension. Any kind of damage to the tire must be checked, as a damaged tire might be unsafe to drive on. The tire in the photo is still inflated, but with damage like this it's not safe and must be replaced.

9. Leaks

Leaking coolant from the radiator

Coolant leak.

Leaks are not always obvious as they often intensify when driving, but stop when the vehicle is stationary. However, drops of oil or fluid on your parking spot should be a cause for concern. If you find a leak, note its position, so the mechanic can find the source of the leak easier. Sometimes, leaks are visible under the hood or when looking underneath the car. Any leak means loss of fluid, and a lack of oil/fluid can cause problems.

10. Unusual smells

When some fluid is leaking under the hood, often the first thing you would notice is a burnt oil or coolant smell. If your brakes are overheating, you might also notice a burning brake smell. A gear oil leak like we described in the beginning of the article will produce a bad sulphur smell. An exhaust smell is an indication of a possible exhaust leak. Any abnormal smell coming from the car indicates a problem that must be checked.

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