The plastic cover under the car fell off. Causes and solutions

First and foremost, sorry for that unfortunate incident, which can be uncomfortable, to say the least. If you are reading this article, chances are that you are seeking to understand why it happened.

So, why did the plastic cover under the car fall off?

Well, it could be that the fasteners(screws, bolts, clips, pins, etc)that were holding up the plastic panel had pulled through and come off the plastic, leaving it with nothing to hold it up.

If not, then perhaps they could have fallen off, leaving it without any fastening. Either way, this usually happens due to some reasons, including washer issues such as if the washers had failed.

Remember that washers play an important role in mechanically fastened parts by keeping the fasteners from loosening or the fastener holes from widening due to one or another reason.

Wrong installation, friction, and corrosion are some of the biggest culprits here. If you plan to sell your car in the future, you can use this “cash for damaged cars” service. You will not have to repair the car before selling it, these guys will evaluate your car in the condition it is in.

More About the Possible Causes of This Problem

As said above, the plastic panel usually falls off because of losing the support of the corresponding fasteners. Again, this usually happens when the screws, bolts, clips, pins, or any other fasteners that the panel is relying on have come off of it due to wrong installation, friction & corrosion, and so on. Here’s more about each issue;

Wrong Installation

The wrong installation means installing the plastic cover onto the car’s undercarriage incorrectly. This can result from lacking the right skills or tools or both that are needed to get the job done correctly.

As such, the fasteners might end up screwed in too tightly, putting excessive tension on the screw holes, washers, and drivetrain in general.

This might cause cracking on the drivetrain, especially around the holes, causing the fasteners to loosen gradually and fall off one after the other to the very last fastener. At that point, the plastic cover can fall off anytime.

Friction & Corrosion

Friction and corrosion can cause abrasion(cutting) as well as wear and tear on the metallic components of your plastic cover installation, thereby affecting its structural integrity.

Consequently, those components(including the fasteners) may shrivel up and lose fit over time. Subsequently, they will slowly lose their hold on the plastic cover until it comes off.

How to Fix a Fallen Car Plastic Cover + Costs

  • Step 1: Clean off the splash shield.
  • Step 2: Jack up the car to get underneath it.
  • Step 3: Clean off the underside of the car and let dry for a few minutes.
  • Step 4: Identify all the fastener holes including those that may still have a fastener.
  • Step 5: Remove a fastener from any hole that has one.
  • Step 6: Re-install the fallen splash shield, fastening it accordingly.

You shouldn’t incur any cost here unless you have to buy some parts e.g. replacement fasteners to replace lost or damaged ones. Luckily, auto-fasteners are generally cheap, costing anywhere from 6-20 dollars.

How Much Does It Cost To Replace Plastic Under the Car?

If you decide to take your car to a mechanic for this task, the amount of cash you’ll part with will depend on how long it will take the professional to complete the task. It will also be contingent upon whether or not there are parts that must be bought.

Usually, the job takes between 15 and 30 minutes, depending on the car. The average hourly rates for mechanics in the States range from $45 to $170, depending on the vehicle and location, among other factors.

Do You Need the Plastic Cover Under Your Car?

Yes, absolutely. Without it, the delicate components underneath your car that stick out or hang down are susceptible to getting damaged by destructive elements like water, dust, debris, etc.

This cover under the car is also known as an engine splash shield and it is made out of plastic and metal depending on the car’s make and model.


Modern cars and trucks often come with a plastic cover that is usually located beneath the undercarriage. This flat panel often protects the vehicles’ underside, which hosts delicate components such as sensors, wires & cables, and so on from potentially destructive elements.

These include water, dust, dirt, debris, and small rocks with which your undercarriage might come into contact.

Unfortunately, the plastic cover is susceptible to falling off due to many issues including wrong installation, as well as friction & corrosion. After all, it’s usually just held up by standard automotive fasteners like screws, bolts, clips, and pins of some sort.

If yours has fallen off, you can quickly install it back by following the simple steps above. Alternatively, your mechanic can help you with that at a reasonable cost. The choice is all up to you.

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