What is a tune-up, and when do I need one?

Keep your car's engine running smoothly with a little preventative care.
Repairman doing an oil change on car.
Avoid potential car drama by getting an occasional tune-up. Pixabay

This story originally featured on Car Bibles.

Doing an engine tune-up isn’t as common as it used to be, but it’s not lost in time. While today’s cars are loaded with all kinds of sensors and highly regulated ECUs, you still want to go ahead and perform a tune-up every now and again. At the very least, it’s a way to bond with your car and get you under the hood and give you a better understanding of how everything works in harmony to provide motion. 

A tune-up can also be a crucial form of preventative maintenance that helps you get the jump on catastrophes and keep costly repairs at bay, and it might even help you sort out problems that the onboard diagnostics system isn’t equipped to detect. If you aren’t working with an OBD system, you definitely need to be performing a tune-up religiously, as it will tell you a lot about your engine’s current running condition. 

So, what the heck is an engine tune-up exactly? In truth, it’s one of those things that can mean different things in different situations. We’re here to talk about exactly what a tune-up is and what you’ll want to know before you dive in. 

What is an engine tune-up?

An engine tune-up is essentially the process of freshening your car’s engine by simply going through a few key areas to make sure everything is clean and in working order. We say it means different things in different situations because the exact steps that are required for one engine can be very different from another. 

For example, say you have two identical engines. One with no running condition issues, relatively low miles, and that has been well-maintained. The other is the exact opposite and has high mileage, misfires, leaks, and showing signs of serious neglect. The tune-up process for the low mileage engine is going to be much simpler than it is for the abused. 

How does an engine tune-up work?

If the engine is in relatively good condition, a tune-up really only consists of a few basic steps. First, you’ll want to inspect the fluid levels, their condition, and perform an oil change if necessary. You’ll also want to inspect the serpentine belt and hoses for any signs of age (i.e., cracking or damage) and replace them if necessary—something you can expect to do on a neglected engine. Of course, a fresh set of spark plugs and a thorough inspection of the ignition system are in order, along with cleaning the major fuel and air delivery components. 

In the case that an engine has known issues that are causing rough running conditions, you’ll want to jump on them first. Something like a misfire can be linked to a bad plug that you’re replacing anyway, but you’ll want to make sure a faulty coil or plug wire isn’t left in place as it can let your efforts go in vain. The same thing applies to any fluid, vacuum, head gasket, or manifold leaks that can be causing you heartache.

The exact steps required for a tune-up can vary greatly depending on the age of the vehicle as well. For example, modern engines use coil packs, whereas older engines feature a distributor with plug wires, meaning that classic might need a new cap, rotor, and plug wires, while the new kid on the block only needs fresh coils. Furthermore, the process of cleaning up the carburetor, ignition points—if present—is vastly different than cleaning up a mass airflow sensor, Oxygen sensor, and throttle body. The point is that you will want to keep these basic points in mind and research your exact engine to find out what steps are necessary.

I will say that, regardless of the engine, you want to take the time to inspect each of the spark plugs as you remove them from the engine. Learning how to read them will give you the best insight into the engine’s overall running condition, if changes need to be made, or if any serious issues need to be addressed. On that note, you’ll also want to make sure the new plugs you’re installing are gapped correctly, as that will directly impact engine performance. 

What’s the difference between a tune-up and engine tuning? 

Engine tune-ups and engine tuning are two very different things but often go hand-in-hand. As we know, a tune-up is a process of freshening up the engine’s vital components to ensure everything is in working order. Tuning an engine is tweaking certain variables to enhance performance. 

Tuning an engine primarily consists of changing ignition timing and fuel curves, which is generally handled by computer programmers or performance chips on modern vehicles. While the process of doing so is always warranted when aftermarket parts are installed, even the slightest changes can dramatically impact an engine’s performance characteristics. That’s why it’s commonly done on any kind of performance application regardless of the exact specifications.

I say it goes hand-in-hand with a tune-up because certain tuning procedures benefit greatly from the steps we follow while giving an engine a tune-up. For example, dialing in an engine to perform best with a different intake manifold, throttle body, hopped-up ignition components, or new turbo will go smoother with fresh oil, plugs, and filters than with dirty/faulty components that can throw off the baseline. Furthermore, those modifications can even warrant the use of aftermarket components and different variables like wider or narrower plug gaps. 

In other words, one hand washes the other as tuning needs to be done on a fresh engine, and many new, clean parts may be installed along the way. 

Is an engine tune-up necessary? 

Routine tune-ups are necessary if you intend to preserve engine performance. However, you don’t always need to perform one unless it’s been a while since you have. For example, a coil pack failing just a few hundred miles after your last tune-up only requires replacing the single faulty component and not running through the entire system. It won’t hurt anything to give a comprehensive tune-up in this case, but it’s not exactly necessary. 

The entire idea of a tune-up is to protect or restore engine performance. You’re changing or cleaning the parts we discussed to ensure the engine has the best tools to work with to provide motion. Making sure that the induction system is clean, the ignition is hot, and there’s nothing to hinder the flow of air and fuel through the engine cycle is the key to getting max performance and efficiency out of an engine. 

Here’s the thing, though, you don’t have to wait for problems to arise to give your engine a tune-up. It’s good practice to inspect everything I’ve discussed routinely to get the jump on poor engine performance. The engine type, how hard you are on vehicles, and your existing maintenance drills can determine how often you do so. Those with an exceptionally old or performance-oriented engine might want to run through the machine every weekend, while someone with a newer car or something that doesn’t see much abuse can do so every other oil change. You might not need to replace plugs, coils, or even clean things up each time, but the idea is to keep a close eye on these components to keep performance and efficiency from suffering. 

FAQs about tune-ups

Car Bibles answers all your burning questions.

Q. How often should I tune-up my engine?

A. How often to perform a tune-up depends on a few variables. Some suggest performing a tune-up every 20,000 to 30,000 miles, while others say every 10,000 to 12,000 miles is best. If the engine is driven relatively lightly, then you can likely get away with longer intervals between tune-ups. However, the harder you drive the vehicle, the more frequently you can expect to clean things up. 

Q. How much does an engine tune-up cost?

A. How much you will spend depends on what needs to be addressed and what components your vehicle needs replaced. On a relatively well-kept engine, you might only need to add a few extra bucks onto the cost of a regular oil change to cover cleaners and a fresh set of spark plugs. Things are a little more costly for a neglected or hard-used engine that may need those components along with new coils, belts, sensors, and gaskets. 

Q. How long does a tune-up take?

A. How long it’ll take you to tune up your engine depends on the layout and how proficient you are with working on it. If it’s your first time, expect to put aside a few hours to learn the lay of the land. The more you do it, the better you’ll get at it, and the time it takes to complete can easily shrink to under an hour—depending on the application. 

Q. What do I need to buy for a tune-up? 

A. Surprise, the answer is “it depends” yet again. Engine tune-ups vary depending on the condition of the engine and your regular routine. If you’re only performing tune-ups every 20,000 miles or so, you can expect to buy spark plugs, an oil change, sensor cleaners, and a serpentine belt at the very least. Of course, the more frequently you perform a tune-up, the less you can expect to buy each time. 

Video on engine tune-ups

No, I’m not leaving you to the wolves to sort out all of the details. I’ve actually found a video that does an excellent job of summarizing the entire process as it relates to the average newer vehicle. Keep in mind that it is just a general take, and you should do some research on the exact steps necessary for the vehicle you’re working with to best prepare.