7 signs your car needs a tune-up

Updated Aug 16, 2022 | Same topic: Tuning & Mods

Determine the different symptoms indicating that your car needs a tune-up, and the possible consequences if you ignore these signs.

When we’re sick, we often go to the doctor for a consult. We tell the doctor how we feel and the symptoms we’re experiencing so that he or she would be able to diagnose the illness better.

The same thing goes for cars. If we feel that there are problems in the car, we contact a mechanic and tell them the things we notice so that they’ll be able to determine the main problem.

To know if your car needs a tune-up, Philkotse.com gathers the most common signs to look for:

1. A misfiring engine

Misfiring happens when spark plugs fire at the wrong time - when they’re fouled-up or worn. Worn or malfunctioning spark plugs can also lead to sluggish acceleration, hard starting, and low fuel economy.

Usually, spark plugs last for at least 100,000 miles. However, modern engine computers can compensate for fouled or worn spark plugs. This means it may not be the only or main culprit.

new and used sparkplugs

A misfiring engine happens when spark plugs ignite at the wrong time

2. A clogged or dirty engine air filter

According to tests conducted by the EPA, acceleration will be reduced more than the fuel economy when the engine air filter is clogged or dirty.

Engine air filters gradually get dirty over time, which is why there’s a chance that you might not notice that the car is steadily losing performance until acceleration is already sluggish. If you have not changed the engine filter for a long time, that can also contribute to the problem.

Dirty air filter

The acceleration will be reduced more than the fuel economy when the engine air filter is clogged or dirty

3. Presence of engine deposits

Engine deposits are often the result of contaminated or low-quality gasoline that creates problems in the car’s performance. The solution for this problem might be a fuel system cleanse which can be done with a gas-tank additive or by a repair shop.

4. The check engine light is on

When the check engine light in your dashboard is lit, it signals that something is wrong with the car’s emissions control system. Don’t ever ignore this alert. The effects on your car will depend on what the problem is.

The issue can affect engine performance and/or fuel economy. For example, a malfunctioning oxygen sensor will leave the engine computer clueless about how to properly set the air-fuel mixture. This can lead to poor fuel economy.

Additionally, an oxygen sensor with 90,000 miles or more on it can still function properly that it will not cause the check engine light to illuminate. However, it can still affect the fuel economy.

The performance of the engine can also be reduced if there are serious internal problems like worn piston rings, restriction in the exhaust system or valves that won’t seat properly.

check engine light illuminating

When the check engine light is illuminating, it signals that something is wrong in the car’s emission control system

>>> Read more: 6 Important Car Warning Signs On The Dashboard.

5. Unusual sounds can be heard

If you notice new and unusual sounds in the engine like the transmission grinding and clunking, then it needs to be investigated by a mechanic. There are also other obvious signs aside from the sounds. If you struggle to turn your engine over, or it’s stalling and/or there's smoke coming from the engine, then it’s time for a tune-up.

6. Low fuel economy

If you’re getting fewer kilometers per liter, then it can be an indication that there are problems with the spark plugs. It can also be the result of a clogged or dirty air filter that needs replacement or it’s already time that your engine gets a clean-up.

If your car is returning low fuel economy and is also accompanied by a lit check engine light and unusual sounds, then it’s time to schedule a tune-up.

But, remember that a lower fuel economy figure can also be caused by colder weather or temperatures. Colder temperatures make the charging system and your engine to work a bit harder.

So, if you notice reduced fuel economy during the colder months, then it’s probably normal, as long as it is not accompanied by any odd signs or with the illuminating check engine light.

Gas refill

If you also notice that you’re getting shorter miles per gallon, then it can be an indication that there are problems with the spark plugs

>>> Also check: 9 Ways to Get the Most Out of Your Car’s Fuel.

7. Sluggish acceleration

Slower acceleration is caused by several factors: An old air filter, clogged fuel injectors, compromised distributor points present in older cars, or a sludge-filled oil pan. All of these affect your vehicle’s performance. So, it is best to schedule a tune-up to have them fixed immediately.

car speeding up

If you feel that you’re now having trouble to accelerate your car, it is caused by several factors

What to do during tune-ups

Tell the mechanic everything you notice in your car. Describe the problems you have encountered especially when starting and driving the car. Make a list and show it to the mechanic.

Why your car needs a tune-up

Tune-ups will not only mitigate problems impinging driving efficiency, but it also helps in the longevity of your car. If you ever experience difficulty in steering, braking, and starting your car, you’ll know how upsetting and frustrating it is. 

Car tune-up

Tune-ups will not only mitigate problems impinging driving efficiency, but it also helps in the longevity of your car

>>> Related post: Car tuning for improved performance: Yay or Nay?

You wouldn't want your car investment to be put to waste, would you? If ever you feel or notice that something is off with your car, or it is performing differently than how it used to be, then it is best to schedule a tune-up as soon as possible.

Tune-ups will not only help in eliminating the problems you've noticed, but it also saves your car from any long-term damage that might cost you more money for repairs and will shorten the life of your vehicle.

Hanna Sanchez

Hanna Sanchez


Hanna is one of the most competitive swimmers in the country during her day. It was not long before she discovered her passion for the automotive industry as well. Nowadays, she balances her passion through writing as well as coaching.

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