Diagnosing Car Problems: How to Figure Out Vehicle Problems

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If your car's acting up, it's important to know how to diagnose it. This blog post will discuss tools and techniques you can use to figure out what's wrong with your car. We will also talk about some of the common causes of car problems. So, if your car is giving you trouble, read on for help!

Common Signs of Car Problems

Many of us overlook the importance of diagnosing our car until we feel unusual things happen. However, we shouldn't let the issue worsen before we take action. If you experience these common signs, don't think twice to diagnose it yourself or bring your car to a mechanic:

  • The engine is running rough or stalls out
  • Strange noise coming from the engine
  • The car won't start, or it starts but then dies soon afterward
  • The brakes don't work properly
  • The car is hard to steer
  • There's a leak of some kind

Causes of Car Problems

Pinpointing your car problems might be left you clueless because of numerous possible causes, even if you have a diagnostic tool. Many people find diagnosing a daunting task because specific generic trouble codes are associated with many issues. However, here are some of the most common causes for your reference.

  • Faulty spark plugs or wires
  • Clogged air filter
  • Dirty fuel injectors
  • Low oil level or dirty oil
  • Cracked engine block

If you encounter any of these problems, it is crucial to diagnose the issue before jumping to conclusions. Immediately addressing the issue could save you a lot of money and headaches in the future.

How to Diagnose Car Problems?

For those who aren't skilled in auto repair, figuring out automobile issues can be frightening. Fortunately, simply using your sense of sight, smell, and hearing is enough for most people to know certain symptoms that indicate particular problems with most vehicles. So what are the things to look out for?

1. Check Engine Light

check engine light

If your check engine light illuminates, it's a good indication of something wrong with your car. Bring it in for service and have the problem diagnosed. If you have an OBD tool, you can diagnose the issue easier by plugging it into your car diagnostic port. 

However, if you don't have a diagnostic tool, you can still diagnose by checking and observing your car's behavior.

2. Listen to the Engine

man checking engine

If you're not familiar with how your car's engine should sound, take it to a mechanic and have them listen to it for you. They will tell you if anything is wrong based on the engine's sounds. Listening to your car can tell you about what's going on under the hood. Keep your ears active by listening to odd sounds like:

  • Creaking

A creaking noise often indicates that a car needs an alignment. You will mostly hear it when turning the steering wheel left or right. The steering wheel should be turned in the car's direction. It's as simple as that. It'll only make it more difficult for you to drive safely if the steering wheel feels disconnected or has a lot of resistance.

  • Clunking

Clunking noises can mean anything from loose suspension parts to worn-out engine mounts. This noise usually happens when you go over a bump. Ball joints and bushings should be well-lubricated and move smoothly to eliminate the clunking noise.

  • Grinding

A grinding noise is never a good thing and usually means that something is wrong with your car's brake pads or rotors and should be addressed as soon as possible. If you're hearing this sound, take your car in for service as soon as possible to avoid further damage. You can also do some remedies by simply adding more brake fluid or replacing your brake pads.

  • Popping

If you hear popping noises, it could indicate something as small as a gas cap not being screwed on tightly or as serious as a cracked exhaust manifold. It is usually caused by incorrect ignition timing and indicates that your vehicle requires a tune-up.

  • Whining

A high-pitched whining noise could indicate a problem with the engine, such as low oil pressure or a failing belt. It typically occurs when the engine is under load, such as accelerating.

  • Bubbling or Gurgling

This noise usually indicates that there's air mixing with the fluid. It could be a leak in your cooling system, allowing air into the radiator and increasing the likelihood of overheating. A blown head gasket can allow exhaust to enter the cooling system when the engine runs, causing bubbling or gurgling sounds.

3. Look Thoroughly

a man working under his car

In addition to listening to your car, you should also take a good look at it. Looking at your car can help you diagnose problems before they become bigger issues. Here are a few things to do:

Examine Under the Hood

Check under your hood for any problems. Make sure you understand where the fluid levels should be. Check to see if the hoses and cables are attached to the components they should be connected to.

Inspect the Dashboard

While the car is parked, perform a quick inspection of the dashboard and center console components. Test the components such as turn signals, windshield wipers, AC controls, and audio system controls to ensure operation.

Check for Fluid Leaks

If your car is leaking fluids, it's a sign that something is wrong. The most common fluid leaks are engine, transmission, or power steering.

Watch Out for Oil on the Ground

If you see oil on the ground under your car, there is likely a leak in the engine. This situation needs to be addressed as soon as possible, as a lack of oil can cause extensive damage to the engine.

Check Coolant Leaks

If you see coolant leaks under your car, there is likely a leak in the radiator or hoses. This situation also needs to be addressed right away, as a lack of coolant can cause the engine to overheat.

Inspect Smoke from the Exhaust

If you notice smoke coming from your car's exhaust, it's a sign of something wrong with the engine. The most common causes of smoking exhausts are worn-out spark plugs, a bad ignition coil, or a leak in the head gasket.

Inspect Your Tire

The tire problem is one of the biggest problems of a car yet the simplest one. However, if your steering wheel starts to shake, your car feels like it's "pulling" to one side, or you hear strange noises coming from your wheels, you will likely have a serious tire issue. 

Check your tires' air pressure first, as a simple fix could be as simple as inflating them. But, if nothing happened, check out for your shocks.

Failed shocks frequently cause a car to tilt off-balance, which is obvious, but you'll also notice a rough ride and a pulling sensation. If a wheel bearing or steering linkage fails, you'll notice a distinct pull. If your car is making strange noises, chances are it's something you can fix yourself or have checked by a professional mechanic.

4. Check for Unusual Smell

auto mechanics check engine

Another way to diagnose your car's problems is to use your nose. Keep your nose active by sniffing around the engine and looking for trouble. Unlike noise or motion, unusual scents are simpler to detect since they're typically more apparent. 

There will always be background noise and natural vibrations in a car, but the odor is generally more or less neutral. Watch out for any smell like:

  • Burnt Rubber

A problem with the brakes usually causes this smell. Check your brakes and brake pads to see if they need to be replaced.

  • Sulfur or Rotten Eggs

A problem with the catalytic converter usually causes this smell. Water and sulfuric acid are sometimes used in combination to fill automobile batteries. As car batteries near their end life, the water may evaporate, upsetting the proportions and making the sulfuric acid more noticeable. 

When the catalyst converter deteriorates, it emits an offensive odor that you can smell through the exhaust pipe.

  • Sweet Smell

A coolant leak usually causes this smell. Coolant, or antifreeze, is crucial to maintain your engine's correct temperature. Leaking coolant increases the chances of overheating and serious engine damage, so if you smell sour milk, have your car inspected as soon as possible.

  • Smell of Mold or Mildew

If the interior smells like mildew or mold, the possible problem is the air circulation system. The smell may originate from the cabin air filter, especially if it hasn't been changed. Several AC or heating issues can cause this odor. 

To identify the leak, check your floor mats, the trunk, and the area around the windshield. If you find water, clean it up and take your car in for a checkup. This can cause aircon problems.

  • Smell of Gasoline

A common sign that your car has a problem is the smell of gasoline. Many reasons could cause this, from a leaking gas tank to a faulty fuel pump. Have a professional mechanic check the fuel system for leaks and have them repair it as necessary.

Exhaust gas contains carbon monoxide, which, if inhaled, can cause loss of consciousness and even death. 

Warning: If you notice any of these smells, it's time to take your car in for repairs. Not only are they unpleasant, but they can also be dangerous. So keep your nose open and watch out for any strange smells while driving!

Possible Car Problems and Diagnosis

Car Vibrating

Several issues can cause shakes and vibrations, so check them all before doing any repairs. You first need to inspect the wheels and tires because vibrating could be coming from misaligned or out of balance, causing poor handling and reducing fuel economy while increasing tire wear. 

Power Steering Not Working

If you have lost power steering in your vehicle, the cause is most likely a broken belt or a belt falling off its track. It could also be due to a steering fluid leak or an internal problem with your pump or gearbox. You must check the power steering belt, fluid level, and hoses to diagnose this issue. 

Car Won't Start 

This can happen if there's a potential problem with your battery, alternator, starter solenoid, or wiring. Check to make sure all of your fuses are in good condition, and none have been blown. Also, make sure your ignition switch is in the ON position. If all of these things check out, you likely have a problem with your starter.

Windows Not working

The window is the most often neglected part of our car. Some of us think that windows don't need maintenance, but they do. The common problem with car windows is that the switch goes bad. To diagnose this problem, try wiggling the switch to see if it makes contact. If it doesn't, then you need to replace the window switch.

Car Overheating

Your car's engine runs hot, and it can cause a lot of damage if it's not taken care of. This problem has several causes, from a blocked radiator to low coolant levels. To diagnose the root cause of your car's overheating, check the radiator, hoses, and thermostat to ensure everything is functioning properly. 

These components shouldn't be blocked or damaged. If the problem persists, there may be an issue with your water pump or fan.

Engine Misfiring

A misfiring engine is often caused by a spark plug not firing correctly. Have a mechanic check the plugs and replace them if necessary to resolve the problem.

Tools You Can Use

Diagnosing your car yourself will be a lot easier if you have tools. However, having these things in your toolbox doesn't guarantee that you will solve your car problem. It is still important to have enough professional knowledge before diagnosing your car. 

But if you are confident enough with your skills and you're ready to do it yourself, these are the tools that you can use:

  • OBD2 scanner- Reads error codes from your car's computer system.
  • Voltmeter- Tests the voltage of your battery and electrical system.
  • Pressure gauge- Measures the air pressure in your tires.
  • Screwdriver set- Checks the tightness of screws and bolts on your car.
  • Socket wrench set- Removes bolts, nuts, and other parts of your car.
  • Torque wrench- Tightens screws and bolts to the correct specifications.
  • Pliers- Helps you grip objects that are difficult to hold with your hands.
  • Flashlight- Helps you see in tight or dark spaces.

Diagnosing Car Problems FAQ

1. How much does the diagnostic test cost?

Diagnostic test costs may vary depending on the type of car, the needed tools, and the garage.

2. Can I diagnose a car myself?

Yes, you can do it yourself, especially if you have a diagnostic tool. A scanner will help you find and address the issue quickly.

3. Where can I bring my car for a diagnostic test?

You can bring your car to any qualified and experienced technician to ensure that you solve your car problem. 

4. What will happen if you drive without diagnosing the car?

It depends on the condition of your car. If your car has severe engine problems, it may lead to a serious accident. So, it is important to check your car before leaving for a drive. 

5. How often do I need to diagnose my car?

Diagnosing your car is crucial to preventing accidents. Most accidents happen due to irresponsible car owners that don't bother checking their cars. You should do a once-over diagnostic every time you get an oil change. However, if you're experiencing any of the common signs listed in this article, take your car to a mechanic for a complete diagnosis.


One of the most crucial things to know is how to diagnose a car problem. Without understanding what's wrong with your vehicle, you can't make an informed decision about which direction to take in terms of repairs or replacement. However, there are some tools to make the diagnosing process easier.

By being aware of the common signs that something is wrong with your car, you can be proactive in getting it fixed before it becomes a more significant issue. And, if you do experience one of these problems, don't hesitate to take your car in for a full diagnosis—you may save yourself from some expensive repairs.