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How To Do A Tune Up On A Car


Most car owners are familiar with the term ‘tune up’. However, many of them are uncertain what it means and what exactly it does for their car. The origins of car tuneups date back to the dawn of cars, when everything was mechanical. Unlike modern cars, older engines had carburetors that prepared air and fuel mixture. With time, these devices would get dirty and covered with built-up. This meant they needed to be cleaned on a regular basis. Also, adjusting things like choke, idle speed and air-fuel ratio was necessary. Additionally, an ignition system used the distributor with mechanical switches to fire a spark in a specific cylinder. They would wear out over time and needed replacement. In the end, a mechanic would adjust all these parts together to work at optimum efficiency.

Are Tune Ups Necessary?

Modern cars have a fuel injection system, various sensors and a distributorless ignition, making it work at optimum efficiency most of the time. Without moving mechanical parts, there are no wear related issues. Still, all of this doesn’t mean that your car is maintenance free. While older vehicles required a tune-up every 10,000 to 20,000 miles, a more modern vehicle is can go anywhere from 50,000 to 100,000 miles between tuneups.

Some benefits of performing a tune-up are idle improvement, better fuel economy and increased overall performance. Additionally, there is a less chance of mechanical breakdown. Not performing regular tune ups on your car can cause an excessive build-up inside the engine. This can lead to failure of engine internal components and emissions related systems, such as EGR or the catalytic converter.

What Are The Signs That Your Car Needs A Tuneup?

spark plug wires

Although tune ups are best done as preventive maintenance, you should also do it if you notice any of the following symptoms.

  • Illuminated ‘check engine’ light shows a problem with fuel, ignition or emission control system. As there are many possible causes for this, it is best to check stored codes with a scan-tool.
  • A sudden decrease in fuel economy is a sign that your car is not performing as efficient as it should. If you feel that your car needs more frequent fill-ups, although you are travelling the same distance, you might have a reduced fuel economy. Usual causes for that are either engine related problems or increased rolling resistance, such as low tire pressure or jammed brake.
  • When not running at its best, your engine will have less than expected horsepower. As a driver, you will notice this as a sluggish acceleration and poor throttle response. If you feel like your car is not pulling away as fast as it did before, have it checked and tuned up as soon as possible.
  • Engine running and driveability problems are certain signs that your car needs immediate attention. These include misfires, juddering and various engine vibrations. In most cases, the cause is within ignition related issues. Take care of this with no delay, as driving your car like can cause additional damage.
  • Smoke from the exhaust is a definite sign of combustion problems. Depending on the color, this can mean either that the fuel mixture is not good or that the engine is burning oil or coolant. In both cases, this will damage the catalytic converter other exhaust components in the long run.

What Does A Tuneup Consist Of?

Although traditional tuneup procedures are not applicable on modern cars, there is still a range of components that need regular replacements to keep your car up to spec.

A good and strong spark is essential for engine optimum performance. Spark plugs have a metal tip or electrode that wears down overtime from heat and pressure. The most common symptom of worn out spark plugs is a random misfire, usually occurring under acceleration. As this is very damaging to the catalytic converter, it is best to replace spark plugs with every tune-up. Use only those spark plugs that meet manufacturer specifications, with correct thread length and heat range. On modern cars, a spark plug gap needs no adjustments, as it comes pre-set from the factory. Before installing a new spark plug, apply a small amount of anti-seize compound on the thread. This will help when replacing the plugs in the future. However, be careful not to get anti-seize anywhere else but on the plug threads.

worn spark plug

Ignition wires are next important parts that need regular replacement. They wear out because of heat exposure and oil contamination. Symptoms of a worn or failing wire are rough idle, loss of performance and even a misfiring cylinder, if the wire fails completely. To prevent installing the wrong wire on the wrong plug, replace one wire at a time. While most vehicles use ignition wires, some newer cars have coils on plugs. With this setup, ignition coils mount directly on the spark plugs. Even in this case, there is a spark plug boot that wears down and needs periodic replacements.

An engine air filter is another component that needs replacement on every tune-up. It ensures the longevity of your engine by removing dirt particles from the fresh intake air. However, air filter gets clogged over time and becomes less effective. Eventually, the flow resistance rises, impacting the engine performance.

The fuel system needs to be clean and free of dirt. Deposits in your fuel system can lead to rough idling, engine hesitation, and overall poor performance. They can also reduce your fuel economy. In addition to changing a fuel filter, you may use a fuel system cleaner treatment. This can help remove contaminants and increase performance and fuel economy.

Lastly, an oxygen sensor or O2 sensor is something that may need periodic replacement. Depending on the age and engine type, your car may have one or more. This important part helps monitor air and fuel mixture, directly affecting both fuel economy and drivability. With time, soot and carbon in the exhaust gas clogs the sensor, giving inaccurate readings. This can cause low gas mileage, rough idle or loss of power. Although it is unnecessary to replace the oxygen sensor on every tune-up, consider a new one if you notice some of these symptoms.

How Much Does It Cost To Get A Tuneup?

The cost of tuneup depends on several factors and can vary a lot. One thing to consider is the type of car and the engine installed, as this affects the amount of replaced parts and spent time. Doing a tuneup on a small 4-cylinder engine is much simpler than doing a big and complicated V8. Other than that, the scope of the tuneup, being a simple or an extensive, will have a big impact on the overall price. Lastly, choose the garage with care, as the labor prices can vary from one place to another.

dirty engine air filter

Generally, you can see anything from $50 for a simple tuneup on a small hatchback, to up to $1,000 for an extensive and detailed tuneup on a big luxury car or SUV.

Save money by performing a tuneup yourself with a automotive workshop manual for your car.


About Bojan P

My name is Bojan - I am a car enthusiast, specialised in the vehicle diagnosis, repair and maintenance with 10 years of practical, hands-on experience. In addition, I have a Masters degree in mechanical engineering.

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