Truck Smells Like Burning Plastic—What Could Be Wrong?

Does your truck suddenly smell like burning plastic while you’re driving, and you want to know what could be causing it? You’ve come to the right place, for we have researched this question, and we have the answer for you.

The most common reason for the burning plastic odor inside your truck is that there is burning plastic somewhere. If any of the electrical components of your truck comes into contact with the exhaust manifold, the surface layer of the wire will start to melt and smell like burning plastic.

Other possible reasons include the following:

  • A plastic object stuck on the surface of the exhaust
  • Worn heater
  • There is a short circuit
  • Faulty fan
  • Loose belt

Let’s talk more about the different reasons why there is a smell of burning plastic inside your truck in the succeeding sections.

Read on!

Big black dual rear tire diesel truck, Truck Smells Like Burning Plastic - What Could Be Wrong?

The Smell Of Burning Plastic

The smell of burning plastic inside your truck is often a group of similar odors that smells like each other. It can smell like burning chemicals, rubber, burning electrical, or the smell of throwing a plastic straw into a bonfire.

Fortunately, most of these odors that you smell inside your truck come with a visual component or symptom that you can check to verify the source of the smell.

What to do when you smell something burning?

The smell of something burning while you’re driving your truck is never a good sign. Slow down and look for a good place to park your truck. Start to look for any signs of smoke coming from anywhere on your truck once you are in a safe place.

Open the hood of your truck and check the engine bay. Be careful when opening the hood of your truck in this situation because it can be too hot to handle.

Look for smoke inside the engine bay. Any smoke coming from inside the engine bay is likely the source of the odor that you’re smelling inside your truck.

If you don’t see any smoke, wait for your truck to cool down before driving off. Set up an appointment with a professional mechanic or bring your truck to a service center. They should locate the source of the smell and take care of it for you.

Plastic Object Stuck In Exhaust

Plastic Object Stuck In Exhaust - Exhaust pipe on pickup truck car close up  Car pollution concept

It is not unusual to encounter plastic bags on the road. Some of these bags can be caught in the exhaust pipes as you drive on the road. The temperature of the exhaust pipe will immediately melt a plastic bag and create the smell of burning plastic.

You can stop at a safe place and check under your car to confirm the presence of the plastic bag under your truck. Do not attempt to remove the plastic bag with your bare hands because the heat will burn your hands.

Wait for your exhaust pipe to cool before attempting to remove what is left of the plastic bag.

Faulty Seat Heaters

Faulty Car Heaters - Detail of the heated seats button in a car.

Some models of trucks and cars have seat heaters. Some even have steering wheel heaters. Seat heating is not new. You can find seat heaters in vehicles going all the way back to the 1970s.

Car manufacturers achieve seat heating by installing heating pads on the seat bottom and the backrest. A circuit connects the heating pads to the heating control on the doors or instrument panel.

Unfortunately, despite the long history of seat heating in automobiles, there is no regulation to oversee the manufacture of heating pads for car and truck seats. Because of this, the heating pads can get too hot even though their maximum temperature can be set by the manufacturer in the ECU (electronic control unit) of the vehicle.

When the heating pad gets too hot, it can burn through the foam and the leather cover of the seats. What you could be smelling is the odor of burning leather or melting foam.

Bring your truck to a professional mechanic to verify the problem and fix it for you. A heating pad that produces too much heat is a fire hazard inside your truck.

How to identify a short circuit in a truck?

There is a short circuit - Short circuit in the car. Male electrician holding a charred wires.

An electrical short circuit happens when the electrical current flows to where it should not go.

This can happen when there is an error in the electrical harness of your truck. Maybe you had some wiring work done, and the mechanic did not properly reinstall the wires.

The most common reason you have an electrical short circuit is when small animals chew on the wire covers, exposing the wire underneath. This can lead to accidental contact between wires that should not come into contact, leading to a short circuit.

Wires that come into contact with the exhaust manifold or exhaust pipes will start to melt and expose the copper inside, leading to a short circuit.

In most cases, the fuses in your truck will automatically protect the circuits by breaking the flow of electrical energy in case of a short circuit. However, there are some situations where the fuses will not be able to stop a short circuit.

Short circuits generate heat on the affected circuits. This is where the burning smell comes from. If the short circuit is next to combustible material, it can cause that material to ignite and start a fire.

A short circuit can also cause an electrical malfunction in other electrical components of your truck, like the heating pads of seats or fans. It can also prevent the engine of your truck from running properly. It can even prevent it from even starting.

Bring your truck to a professional mechanic as soon as possible to locate the short circuit and fix the short circuit before it creates an even bigger problem.

Can a faulty fan produce a smell of burning plastic?

Faulty fan- Old radiator cooling fan motor of truck engine

There are fans inside your car that help your truck to run smoothly.

A fan blows cold air into the passenger cabin of your truck. Fans help prevent the head unit from overheating. And a fan pulls air through the radiator fins when your truck is not running fast enough to prevent the engine from overheating.

Fan blades are always made of plastic, ensuring the fans will be light enough to be efficient. These blades are held in the correct position by a small metal axle which is, in turn, held in place by plastic.

Natural wear and tear can cause the metal axle to misalign. Even the slightest misalignment can cause the plastic fan blades to tilt and rub against the surface of the grills that protect the fan.

This rubbing creates friction that can eventually melt the plastic fan blades. This can create the smell of burning plastic.

Another situation is when the temperature of the radiator becomes too much for the radiator fan. The radiator fan can slowly melt and misalign, causing the plastic fan blades to rub against the radiator fins. The smell of burning plastic will come from the melting plastic because of an overheating radiator and from the fan blades rubbing against the radiator fins.

Bring your truck to a mechanic to check the system fans for issues and replace them if necessary.

How to diagnose a faulty serpentine belt?

The accessories of your truck often receive power from the engine. These accessories include the power steering pump, the AC compressor, the oil pump, and the alternator.

A serpentine belt connects these accessories to the crankshaft. The rotational movement of the crankshaft provides power to these accessories.

As the serpentine belt nears the end of its service life, it starts to become loose. A loose serpentine belt will start to move outside of the pulleys and tracks. This will cause it to rub against the different surfaces of the accessories to that it provides power.

Some of these surfaces are made of plastic. The constant rubbing of the serpentine belt on these surfaces at high speed will generate a lot of heat.

Once this happens, you will notice smoke coming from the engine bay along with the smell of burning plastic. You will also notice the smell of burning rubber because serpentine belts are often made of rubber.

Replacing the serpentine belt of your truck is an easy DIY. However, if you’re not confident enough to do it yourself, you can bring your truck to a mechanic to do the replacement for you.

Bando USA Serpentine Belt is available on Amazon through this link.


The smell of burning plastic inside your truck comes from burning plastic. You need to find where that smell is coming from as soon as possible because most of the causes behind the smell can potentially become a bigger problem or lead to worse damage.

If you enjoyed reading this article, you might find the articles below equally enjoyable to read:

Debadging Toyota Tundra Without Damaging Paint [How To]

Chevy Truck Not Shifting Gears—Why And What To Do?