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      Your concern might be complex to diagnose and may require additional equipment to pinpoint the cause. In this case, you'll receive Digital Inspection results plus a quote to perform deeper diagnostic/test procedures.
      Home / Symptoms / Burning Plastic Smell

      Hey, Why Does My Car Smell Like Burning Plastic?

      The burning plastic smell is caused by the following:

      If you are short on time and want to fast-track the process to professional help, click
      Four common causes for a plastic burning smell from the vehicle and their related parts.
      Another cause of a burning plastic smell could be any type of electrical system overload. Plastic coatings on wires can become heated beyond their limits. Burning can also occur when there is an electrical short circuit. Since most modern cars and trucks have a substantial amount of computer, electrical, or sensor wiring to ensure all essential control functions in your vehicle are working, it is vital to keep them running correctly. Be prepared to share with your trusted shop how they can best reproduce what you’re experiencing during their testing.

      Common Causes For a Burning Plastic Smell?

      The burning plastic smell is typically related to any electrical system overload. Plastic coatings on wires can become heated beyond their limits. Burning can also occur when there is an electrical short circuit.

      • Melted fuse box: The fuse box holds many fuses and connectors and has a vital role in the car's electrical system by protecting circuits and components. However, it can burn if there's an electrical overload or short circuit, producing a burning plastic smell.
      • Faulty blower motor: The blower motor is a mechanism that forces airflow in the vehicle and is essential for A/C and engine cooling. However, it can overheat due to internal electrical issues, causing a burning plastic smell.
      • Faulty alternator: The alternator is crucial to the electric system in a car; it's basically the powerhouse that generates and recharges the battery. Unfortunately, it can overheat and burn internal components, causing a burning plastic smell.
      • Road plastic on the exhaust: Road plastic like shopping bags or plastic debris can bounce on the exhaust and get stuck from the heat. In this case, the plastic keeps burning and producing a telling smell.
      • Relay failure: Relays are vital components in the electrical system; they transfer electricity from the control circuit to the main circuit, basically making a small switch activate a bigger car function(like turning a switch to activate the headlight). However, they can overheat due to exaggerated power drawing, causing a burning plastic smell.

      A burning smell coming from the car is typically an early sign of damage. Unfortunately, turning a blind eye to the problem puts expensive wiring, harnesses, connectors, and computer controls at risk.

      First, search under your vehicle for plastic bags stuck in the exhaust. In some cases, the plastic melts, and the burning smell travels through the heater and air-conditioning vents. If the problem persists, serious car problems might evolve.

      Since most modern cars and trucks have a substantial amount of computer, electrical, or sensor wiring to ensure all essential control functions in your vehicle are working, it is vital to keep them running correctly. Be prepared to share with your trusted shop how they can best reproduce what you’re experiencing during their testing.

      Let's Get To The Bottom Of It!

      Are you noticing problems with your car's stereo, lights, or starting process?

      Problems with your car's stereo, lights, or general accessories accompanied by a burning plastic smell can have to do with the alternator. The alternator is a component under the vehicle's hood that generates power for extra accessories, such as the radio, cabin lights, etc.

      However, alternators can develop issues and cause overheating. Commonly, damaged alternator terminals can melt and burn wire connectors, causing a burning plastic smell.

      Have you checked if there's something stuck under your car?

      Debris stuck in the car (like a plastic bag) starts melting as the engine heats, especially on long drives or while cruising a steep hill. Then, fans from the electric cooling and air conditioning condenser overheat because of built-up road debris, causing a high load or electrical short, which is a common problem.

      Do you feel the smell coming from under the car's hood?

      A car's weak or overloaded battery might cause meltings on the fuse box cover. The cover is typically plastic and works like a removable lid containing connectors and relays under it.

      In this case, the excess load made the wires and connectors overheat. As a result, the cover melts, producing a burning plastic smell. Since the battery sits under the hood, the smell might be more noticeable in the vehicle's front area.

      Does the smell appear when turning the heater or A/C on?

      The A/C has components like the blower motor, which are vital to its operation. The blower motor helps move air through the HVAC (Heating, Ventilation, and Air Conditioning) system. This component is part of the electrical system and has various wires and connectors around it.

      The blower motor wires will overheat when using the heater while the cabin air filters are restricted. The air filters can become clogged with dirt, especially if they're too old. Then, the overheating will burn nearby plastic components, causing a smell through the heater and A/C system.

      Are you noticing any electrical failure in your car?

      If, besides the burning plastic smell, you're noticing issues activating some of the car's systems, like internal lights, windows, and sunroof, the issue might be an electrical failure. Each of the car's systems runs on electricity and has plenty of wires and connectors that can burn and stop working. So, if you notice a specific system not working, it might be the culprit causing the smell.

      Plastic generally doesn't handle heat very well. Your car has many complex plastic-y electrical switches, like relays, which constantly transfer high loads. Unfortunately, this part can fail and cause burning plastic smells.

      Find Professional Help

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      If you are a shop owner and sick of business directories that are based on the cost of repair, AutoTechIQ is for you. If your customers receive Digital Inspection results then AutoTechIQ is definitely for you. Check out the certification page or how to rank in your area.

      Vehicle Health Inspection Proof

      Explore the following typical inspection results that show a potential cause for the symptom and select the one you believe is similar to your vehicle's issue.

      • Plastic burning on the exhaust
      • Faulty blower motor
      • Melted fuse box and cover
      • Relay failure
      • Bad alternator
      Plastic burning on the exhaust causing the burning plastic smell from the vehicle

      Lifting the car and inspecting its underside is essential. The image above shows the exhaust pipe with plastic melt marks, possibly from road trash. The garbage was sticking to the hot exhaust, making the car immediately produce burning smells.

      Splash shields are parts that prevent water and other objects from sticking under your car. In this case, the owner removed the plastic shield because it was damaged. Without replacing it, the car's underside became vulnerable to plastic bags, etc.

      Does the issue look like this? if not accessible your shop will document it

      Typical Makes

      That need Burning Plastic Smell significantly more often than average vehicle makes

      • Volkswagen
      • Audi
      • Ford
      • Cadillac
      • Chevrolet
      • GMC
      • Toyota
      • Acura
      • Honda
      • Make: Volkswagen
      • Model: Beetle, Jetta, Golf
      • Fuse Block Replacement
      • Is this the make you are driving?
      Fuse box VW

      Typical Fixes to Address the Cause(s)

      The following chapters bases themselves on experiences from our auto repair shop; we'll describe related problems' causes and fixes.

      • "Fuse Box Replacement" fixes "Melted Car Fuse Box and Cover"

        • Fuse box replacement by the glove box

        The AutoTechIQ ranking for Safety, Cost Avoidance, and Environmental Impact is

        Safety
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        Cost Avoidance
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        Environmental Impact
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      • "Blower Motor Replacement" fixes "Bad Blower Motor"

      • "Alternator Replacement" fixes "Bad Alternator Symptoms"

      • "Splash Shield Replacement" fixes "Plastic Burning On Exhaust"

      • "Relay Replacement" fixes "Car Relay Failure"

      Sometimes a problem is more challenging to describe than it initially looked like. If you are not sure your problem is described by this article, please find below similar vehicle symptoms, which might describe better the issue you are experiencing.

      Vehicle Symptoms

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      Typical Fixes Pages