Burning Rubber or Plastic Odor

If you find your nose plagued by the pungent aroma of a burnt plastic or rubber while driving, you likely are overheating your brakes or have a clutch that is slipping.

1. Check the Common Items
Oftentimes, one of two common causes are responsible for your brakes overheating; an emergency brake left engaged while driving, and the "breaking-in" of new front pads.

If you haven't had front brakes recently installed, check that you have disengaged your emergency brake. Driving a short distance with the e-brake applied can cause the rear shoes to overheat and to give off a strong odor. If this is the case, simply disengage the brakes and proceed to drive normally. (However, if you have gone quite some distance with the e-brake engaged, you should have the rear brake lining checked.)

Alternatively, if you have just had new brake pads placed on your vehicle, it would not be unusual for you to notice the same burnt rubber smell for a brief period as the brakes "break-in." If the smell persists however, (more than an hour or two), your front brake calipers may be stuck on. This usually occurs when the pistons in the front calipers rust or wear out and begin to seize. Always ask your mechanic to check the calipers and other braking hardware (or do so yourself) when changing your brake pads.

2. Dig a Little Deeper
If your e-brake is disengaged and you haven't had new pads installed recently, you might need to look a little further for the source of the smell. Check to insure that the e-brake cable is truly disengaged and didn't accidentally break or become rusted and locked on you. A few simple tests can help find an answer here.

You can simply jack up the rear of the car so both wheels are slightly off the ground. Place your transmission in neutral, and try to manually spin the rear wheels. If the wheels are difficult to turn or won't move at all, the brake is likely engaged. For further testing, you can find an open area where you can safely drive a straight line at about 20-25 mph and then release your foot from the gas. If the brake is stuck (engaged) the car will slow rapidly rather than rolling freely until you apply the brake.

If you have tested and found that the brake cable is definitely disengaged, you may want to have a qualified mechanic look at your clutch (standard transmission vehicles only). When a clutch wears or is incorrectly aligned/adjusted it may slip and overheat causing a smell similar to the one caused by overheating brakes.