As more and more people travel on public roads every year, the roads become subject to more and more degradation. Unfortunately, this means that there is an increasing buildup of dust, debris, and other hazards. For this reason, auto manufacturers started putting on an engine splash shield to cover the undercarriage of the car from the road. Engine splash shields are also useful for off-roading vehicles that see increased road hazards on the terrain.
This guide will cover everything you need to know about engine splash shields. We’ll go over their function and purpose, explain whether or not they are necessary, and finally we’ll go over how to fix a damaged engine splash shield if you find yourself with one. We will also cover the costs of replacing an engine splash shield. Let’s get started.
What is an Engine Splash Shield or Skid Plate?
The engine splash shield, also sometimes referred to as a skid plate, is a piece or pieces of steel, metal, or plastic, that protect the undercarriage of your vehicle. Every car has their own unique splash shield designed specifically to match its unique contours. Some engine splash shields only cover the very front of the car, while others cover the entire underside of a vehicle.
You might have also heard of an engine splash shield referred to as a skid plate, underbody cover, undercarriage cover, or a myriad of other similar names, but they all refer to the same thing. The most common terms are splash shield and skid plate. Typically, people will use the term skid plate to refer to a metal or steel piece, and use engine splash shield to refer to a plastic piece.
Whatever you call it, the splash shield functions by stopping road debris, dirt, water, snow, ice, mud, and pretty much anything it can from hitting any important part under the car or in the engine bay. It also makes the car more aerodynamic and reduces road noise.
What is a Skid Plate’s purpose?
The main purpose of the skid plate, as we just mentioned, is to prevent anything on the road from entering into the engine bay. This isn’t just limited to the elements like rain, snow, and mud. As anybody in a major city will tell you, roads are often filled with broken bits of asphalt, random bits of trash, and even fallen car parts from previous drivers with cars in less than optimal condition. Any of these can potentially get kicked up by your tires and hit something on your engine and cause serious damage.
All engines are designed and configured differently, and some engines have incredibly vital components like oil filters or turbochargers located on the bottom of the engine. For example, the 2015+ Subaru WRX features a low mounted turbo that actually sits under the engine. Needless to say, it’s important to protect expensive parts like those from unnecessary damage.
Engine splash shields also help keep the engine bay cleaner. By stopping dirt, snow, rain, mud and other elemental debris from splashing up, the bay stays much cleaner. Keeping the engine bay clean and void of dust and dirt helps your air filter last longer and stay cleaner. For cars with intercoolers, it’s crucial to keep the bay clean of dust and dirt. If it gets too dusty, some of that can make its way into the intercooler, making it work less efficiently and reducing cooling.
They also help with aerodynamics and noise insulation. By giving air a smooth path to follow instead of allowing it to get trapped in the engine bay, splash shields help make cars more aerodynamic. The shields also reduce the amount of road noise that infiltrate the cabin, making for a more pleasant driving experience.
Is an Engine Splash Shield necessary?
Is an engine splash shield necessary? That depends. For the most part, skid plates are not completely necessary, but they are very helpful. Chances are, during your average commute you won’t drive over any objects that would actually fling up into the engine bay and cause damage. In addition, the minimal aerodynamic improvements and noise insulation don’t make huge differences.
However, there is also virtually no reason not to have a skid plate. They add only minimal extra weight and have the potential to prevent serious damage. They also keep the engine cleaner, which like we mentioned helps with intercooler and air filter longevity. Engine splash shields also prevent water from entering the engine bay and intake from below, potentially preventing hydrolocking from occurring. There are basically no downsides to have a properly functioning engine splash shield.
If you like going mudding or off-roading, then you will definitely want to keep your skid plate intact. You are much more likely to have issues with rocks and objects that could potentially stick into your engine when off-roading. Getting stranded in the mountains or woods is not a good predicament, and splash shields are cheap insurance. If you do damage your splash shield, we highly recommend replacing it as soon as you can.
Engine Splash Shield Repair and Replacement
Speaking of engine splash shield damage, let’s talk about what to do if yours gets damaged and needs repair. While this is not the most common of issues, it can happen from time to time depending on road conditions and off roading. Like we said above, if you do have damage on your splash shield we highly recommend replacing it ASAP.
Diagnosing a damaged Skid Plate
People will typically notice a damaged skid plate when doing work under the car, hearing it scraping on the ground when driving, or after seeing the engine splash shield hanging down from the car. Most of the time, the damage is caused by driving over a foreign object like a curb or road debris.
Diagnosing a damaged engine splash shield is easy enough. If you suspect damage, simply jack up the car if you can’t already fit under and inspect the skid plate. If it is cracked, has hanging or missing pieces, or has lost structural integrity and is flopping around, it’s time to replace. Keep in mind, plastic underbody covers will have some flexibility, but they should still be relatively sturdy.
Damaged and Hanging Engine Splash Shield Repairs
If you inspect your skid plate and notice that it is damaged it’s time for a repair. Luckily, the repair is very easy and you do not have to be very mechanically inclined to successfully do it.
Your first step is to inspect the damage and see how severe it is. Since you probably won’t have a spare engine splash shield on hand, you will want to see if you can do a temporary repair to keep it functioning until you source a replacement. It won’t be pretty, but some duct tape on a plastic shield will probably do the trick for a few days. If the damage is too severe, you can always remove the shield for a few days while you get a replacement, just be cognizant of what you are driving over.
Once you have a new skid plate (more on purchasing one below) you can go about removing the old one. Most splash shields are held on by screws, push-clips, or torx-screws. Depending on what you have, remove all fasteners and you can remove the splash shield.
Next, take the new splash shield and install it to the car using new fasteners. If your replacement is not a direct fit you may need to cut some areas to ensure proper fitment for your car. That’s it, you have successfully repaired your broken or hanging engine splash shield. We told you it would be pretty easy.
Engine Splash Shield Repair costs
Now let’s talk about engine splash shield repair costs. If at all possible, we highly suggest doing this repair yourself. It is very easy and will save an hour of labor, which can be upwards of $150/hr. For a direct OEM replacement, depending on vehicle size, you are likely looking at between $50 – $150. Aftermarket skid plates can go as low as $15. We recommend going with OEM if you can find them, as they are not very expensive and are going to have very good fitment. But then again, skid plates are pretty minor, and perfect fitment is far from necessary for them to function.
As long as it works, a $15 skid plate is probably fine for road use, but if you do a lot of off-roading you might want something more heavy duty. Speaking of which…
Skid Plates for Off-Roading
If you plan on taking your truck or car off-roading into hazardous areas with any frequency, we definitely recommend making sure to inspect your skid plates often. You might not hear or feel it, but broken tree branches, stumps, rocks, and just about everything in the backcountry is capable of puncturing them.
If you are serious about doing more advanced off-roading and backcountry driving, and your engine shield is plastic, you might consider upgrading to a steel or metal one. Reinforced skid plates will take a lot more abuse, and will do a far better job protecting against hazards. The last thing you want is a broken radiator or smashed oil filter when repair services aren’t nearby or practical.
Engine Skid Plate Summary
While the engine splash shield might not be the sexiest part of your car, it’s still important. Will your car suffer catastrophic failure without one? Unlikely, but it does have the potential to stop unwanted hazards for banging into your engine, causing serious damage. In addition, you will also see extended air filter and intercooler life due to the lack of dust and debris.
Hopefully, you will never have to replace your skid plate, but if you do now you know how. Let us know your thoughts in the comments below!