When To Replace A Toyota Filler Cap

If you're here, you may be wondering if your Toyota has a bad gas or oil filler cap. The good news is that it's quite easy to identify a bad filler cap. We'll show you how to do this.

Signs Of A Bad Oil Filler Cap

Oil filler cap installed

Image Credit: MyStupidProjects

When an oil filler cap goes bad:

  • Oil can leak out from under the cap and get all over other things in the engine bay
  • Air can be sucked into the engine, which means dust and water vapor can be sucked in

Either scenario leads to problems, some of which you can notice while driving.

  • Unreliable performance of the water pump and other belt driven accessories
    • If oil seeps out, it can contaminate the serpentine belt and cause it to slip.
  • A cracked oil filler cap can cause a vacuum leak. This can result in:
    • Check engine light coming on
    • Decreased engine performance

Signs Of A Bad Gas Filler Cap

Fuel filler cap installed

A gas filler cap covers the fuel tank filler tube. When you fill up your tank with gas, you remove the filler cap before putting the gas nozzle into the tank. Because it is used so often, the seal on the gas filler cap can deteriorate. Or the cap itself may become damaged. When that happens, fuel vapors can escape from the gas tank.

Since you probably use your gas filler cap on a regular basis, you may notice some damage right away. But that's not always the case. Sometimes it can be easy to overlook certain gas filler cap damage, such as a deteriorated seal. So it helps to keep an eye out for the signs of a bad gas filler cap:

  • Gasoline smell
  • Check engine light coming on

Inspecting A Toyota Filler Cap

You don't need any fancy tools to identify a bad filler cap. All you need is a set of eyes and a few minutes. Here's how to inspect a filler cap:

  • Find the filler cap.
    • If you're checking the gas filler cap, it's where you fill up the car with gas.
    • If you're checking the oil filler cap, it's under the hood, usually on the driver's side.
      • Make sure the engine is cool first.
  • Without removing the filler cap, turn it to the right. If it doesn't feel snug after tightening:
    • The threads may be bad.
    • The rubber seal may be bad.
  • Remove the filler cap and then give it a thorough visual inspection.
    • Look for cracks or holes.
    • Inspect the rubber seal. If it's cracked or loose, it's bad.
    • Check the threads. If they look worn, then they're bad.

When In Doubt, Replace The Filler Cap

Toyota filler caps

If you're not sure whether your filler cap is bad, it's a good idea to replace it anyway. There's no harm in investing in a new filler cap. It's better to spend a few dollars on a replacement filler cap than deal with check engine lights or an  oil soaked engine bay. Maybe a new filler cap is all you need to resolve some of the issues you've been experiencing.

We offer wholesale pricing for genuine OEM filler caps. For example, take a look at this gas filler cap for select 2006-2010 Toyota models. It's usually about $30 at dealerships, but you can get it from us for only under $23. Look up your Toyota model in our catalog of filler caps to get what you need for your car!

Written by Jason Lancaster