The most common engine issues and how to diagnose them

15 / 09 / 2021


While there are many critical components like braking systems and ADAS systems in a motor vehicle, none are more fundamental than the engine—unless it is an electric vehicle with an electric motor, that is. 

After all, without an engine, automobiles cannot generate the power required to move their wheels.

As an experienced auto mechanic or someone training to become one, mastering how to spot, troubleshoot, and fix engine issues is perhaps the most critical skill you can acquire. 

Instead of spending too much time identifying what could be the problem, being able to diagnose issues early on or pinpoint the exact issue in a faulty engine can save you plenty of time and effort. 

What’s more, it’s this kind of expertise drivers expect when they consult technicians for repairs for their vehicles today.

In this post, therefore, we dive into some of the most common engine issues you can expect in any vehicle, and how you can troubleshoot these issues.

The most common engine problems in vehicles

At the outset, it’s important to recognize that not all problems in vehicles are caused by the engine itself—faulty spark plugs, catalytic converters, and fuel pumps contribute to numerous issues as well. 

When considering engine-related malfunctions, however, overheating is one of the primary issues many technicians find themselves treating. To operate efficiently, engines need to work within the optimum thermal window or risk performance and longevity issues down the line. 

Another common problem is the loss of acceleration or power from the engine. While transmission issues can also cause acceleration issues, in many cases, it’s a result of engine defects like poor fuel and air mix ratios, a blocked exhaust manifold, and clogged air filters. 

In rare cases, drivers may even encounter misfiring engines, which can lead to high fuel consumption and a loss of general performance. This could be attributed to decalibrated engine timing, faults in spark plug wiring, malfunctioning ignition coils, and vacuum leaks.

How can you diagnose engine problems early on?

As an auto mechanic, understanding the symptoms of engine trouble is key—spotting the problem at an early stage can limit damage to the engine and prolong each vehicle’s lifespan.

Even if the damage is already done, knowing what the signs are will help you get to the root of the problem much faster and identify which repairs have to be performed. 

  • The check engine light

The check engine light is the first indication of a malfunctioning engine. Unfortunately, many drivers ignore this signal, which often leads to severe engine troubles down the line. 

This could mean a few things: a misfiring engine, a faulty gas cap, or even a broken catalytic converter, to name just a few of the most common issues.

The check engine light also lights up in different colors and various blinking patterns, with each color and pattern being a code that denotes various issues. As an automotive mechanic, you can decipher these codes to diagnose and fix engine issues without too many complications. 

  • Exhaust smoke

Engine trouble can also be deciphered by the smoke being released from a vehicle. 

The amount, color, and smell of the smoke can point to different issues in the engine. Faulty catalytic converters, excessive fuel in the combustion chamber, and faulty fuel filters, for instance, are some of the most common issues that lead to excessive smoke.

  • Strange noises

Misfiring in the cylinder can cause various unfamiliar popping noises in the engine. 

What’s more, if the engine doesn’t have adequate lubrication, it may even make a grinding noise while the vehicle is being driven.

You may also hear loud bangs; these generally occur when the engine is being started, owing to unburnt fuel leaking from it and combusting in the exhaust system.

Diagnose and fix engine problems effectively to provide high-quality mechanical services

The engine is the most critical part of any automobile. 

As an auto mechanic, you need to possess the skills to spot any issues related to the engine in its earliest stages and perform the necessary repairs to improve the reliability, safety, and longevity of each vehicle.

To get a deeper understanding of engines, the common problems that affect them, and recommended fixes, up-to-date automotive training may be a useful place to start. 



    Order Summary


    Product Name



    • Subtotal

    • Total

    • *Tax will be calculated at checkout