Caring for your vehicle can be a challenge. If you’re new to cars, you might be confused by all the different parts and their maintenance requirements. For example, if you’ve heard of fender liners, you might wonder: what are they? Does my car have them? Do I even need them?
Here’s a hint: if you’ve ever noticed something flapping around near your car tire and pulled out a sheet of plastic, you’ve come into contact with a fender liner.
In this article, we’ll go over the basics of what fender liners are, what purpose they serve, and how often you’ll need to get yours replaced.
Cars need fender liners. Fender liners provide essential protection to your car’s engine to help improve its lifespan. This is especially important if you live in a place where the temperature drops below freezing in the winter and slush covers the roads.
The outside of your car is weatherproof (to a certain degree). But the internal components of your vehicle can deteriorate if they are not protected. A fender liner keeps your engine protected from the elements by shielding it against dirt and moisture.
When an engine is exposed to these elements, it can retain long-term damage like rust. This can lead to expensive internal repairs. You may even have to get a new car rather than fork over the money for the damage.
Because of fender liners’ particular needs, it’s not a job you should attempt on your own. Instead, bring it into a qualified mechanic for repairs.
In short, a fender liner is a simple preventative measure to protect the interior of your car from damage. Investing in a measure like this and making sure it is up to snuff can extend your vehicle’s lifespan while also keeping you safe behind the wheel.
In this section, we’ll go over this topic in a little more depth. This includes what a fender liner does and how to recognize when yours needs a repair.
What is a Fender Liner?

Even if you don’t know much about cars, you probably know where the fender is. After all, most of us have gotten involved in a “fender bender.”
A fender liner, also called a fender inner liner, is a plastic lining that goes in the car’s interior between the fender and the engine. This extends up over your car’s tires into your wheel well. Fender liners are typically fastened to your car with special clips or screws.
Before the modern era, fender liners were usually made of metal. If you own an older car, you may still have a metal one. These days, they are typically made of thermoplastic. This material is highly resistant to rust and wear.
What Does a Fender Liner do?
A fender liner’s purpose is to protect the engine from all the road’s dirt and grime. This includes mud, dust, snow, water, general grit, and chemical agents like gasoline.
This is important because when these agents come in contact with the engine bay, they can cause damage and corrosion. While the outside of a car is made to repel these contaminants, the engine is not. If the engine suffers damage, it can lead to drastic and costly repairs.
This also holds true for other interior parts of your vehicle. Fender liners also protect other components accessible through the bottom of your car, including your wheel wells and headlights. These parts can also suffer long-term damage from prolonged exposure to dirt, snow, and moisture.
Where is the Fender Liner on Your Car?

Technically, your car has a couple of fender liners. There is one directly behind each front wheel. They aren’t visible regularly, but if you remove a tire, you might be able to see yours up inside the wheel well. These curved plastic pieces fit up over your tire to protect the interior of your car.
Who Needs a Fender Liner?
Everyone who owns a vehicle needs to make sure it’s outfitted with an up-to-date fender liner. But they are essential for anyone who lives in a cold climate. As we discussed above, cold weather is more likely to cause damage to fender liners. Freezing temperatures and dirt and slush flying under the liners can all hurt the car.
How do I Know When My Fender Liner Needs to be Replaced?
Suppose you have an older car manufactured more than 20 years ago. In that case, it’s a good idea to ask your mechanic about your fender liners. This is because older cars often have metal fender liners. While this might seem sturdier and less prone to damage, metal is more corrosive than plastic. There is a good chance that an old fender liner made of metal is rusted and letting moisture into the engine bay.
Even if you have a newer car, you should still have your fender liners checked for damage regularly. This is especially true if you live in a cold climate where slush and mud tend to get splashed up under your car. But even if temperatures don’t drop where you live, you should still have them checked regularly. Any debris in the road can cause cracks or deterioration in a fender liner.
If your fender liner is cracked or missing a piece, you may be able to tell just by listening. If you notice the loud sound of dirt hitting the bottom of your car as you drive, you might need to replace your liners.
What Causes Damage to a Fender Liner?
Fender liners are often damaged during winter, especially if you live in a cold area. Freezing temperatures cause cracking and weakening in the plastic lining. Meanwhile, driving through significant slush, mud, or water or over a curb can also cause damage.
General moisture can also cause damage to a fender liner. This is because, like most other car parts, they corrode with excessive water. Newer plastic ones are more resistant to corrosion, but they will eventually wear away and need to be replaced.
But that’s okay — fender liners are made to be cheap and easy to replace, which is why they protect the expensive, permanent inner parts of your car.
How Much Does a Fender Liner Cost to Replace?

If you are worried that replacing a fender liner will be expensive, you can set your mind at ease. These parts aren’t costly. The fender liner’s cost will vary slightly depending on what type of material you use and what model is best suited for your vehicle.
Any professional mechanic should know how to replace a fender liner. It is a reasonably quick job and shouldn’t take long to do.
Why is a Damaged Fender Liner Dangerous?
We’ve talked about how a damaged fender liner can let moisture and grit into the car’s interior parts. This can lead to expensive repairs. But is driving with a damaged fender liner actually dangerous?
The short answer is — yes and no. Although your car won’t have a mechanical failure or suddenly shut down, it will eventually become less roadworthy. This interior damage could make it dangerous to drive.
Damage to your fender liner doesn’t only affect your engine itself. It can also damage your wheel wells and headlights. If moisture or dirt causes your headlight wiring to corrode, you’re looking at a more annoying and expensive repair. Of course, there is also the obvious danger of driving with less light at night.
How Do You Know What Kind of Fender Liner is Right For Your Car?
We’ve touched on the different materials for fender liners and how they’ve evolved over time. Until a few decades ago, most fender liners were made of metal. These days, they’re usually made with a tough plastic alternative like a thermoplastic.
In some cases, they may even be made from thick rubber. Although these materials are more fragile than metal, they are far slower to corrode, providing longer protection to your car.
It’s essential to get your fender liners checked and replaced regularly. But how do you know which one is the right choice for your car?
The short answer is that you don’t have to. Replacing a damaged fender liner is a job that requires special knowledge, so you shouldn’t attempt it on your own. Your car mechanic will know which model is the right choice for your car and can make a recommendation based on that.
If you want to do your research ahead of time, you can always read up on the different types of fender liners and ask your mechanic what they think. This also gives you a chance to make a price comparison. Regardless, it’s a great way to know more about your car and how to keep it safe.
