Why Do Oil Filters Leak?

Oil leaks can be a real pain. There are many reasons that an oil filter might leak. We'll cover the 2 most common reasons in this blog post.

1. Bad Seal On The Oil Filter

oil filter seal

When an oil filter seal fails, oil starts leaking out of the filter. The purpose of having a seal on the oil filter is to keep oil from leaking out. An oil filter seal can fail for a variety of reasons:

  • Age: Oil filters aren't supposed to be on your car for a long time. So if an oil filter seal becomes brittle, it's definitely time to change the oil filter.
  • Low quality: If you use an aftermarket oil filter, chances are good that the seal on it is made from low quality materials.
  • Wrong size: This is also an issue sometimes found on aftermarket oil filters. If the oil filter is too big or too small, it'll fail to keep the oil sealed in the filter.
  • Manufacturing defect: It's possible for your oil filter to have a defective seal. 

2. Improper Installation

The oil filter is a simple part, but it absolutely needs to be installed the right way. If it's installed wrong, leaks will develop. At most shops, the technician performing the oil change and filter installation is the least experienced and knowledgeable tech in the building. That's why improper installation is fairly common with oil filters.

If an oil filter isn't installed correctly, some of the following issues will develop (and cause oil to leak out):

  • Cracked or worn housing from over-torquing or cross-threading
  • Damaged threads
  • Damaged seal

The Best Way To Avoid Oil Filter Leaks: Only Use OEM Oil Filters

OEM oil filters have a much lower chance of springing a leak than aftermarket oil filters. The reason for this is that aftermarket oil filters are not up to the same quality standards as OEM oil filters.

  • OEM oil filters meet factory specs and standards
  • Toyota uses quality materials to build its oil filters
  • OEM oil filters are always inspected for quality before leaving the factory

An OEM Toyota oil filter has a better chance of preventing leaks than an aftermarket oil filter. So it makes sense to go with the option that's less likely to fail. Only use OEM Toyota oil filters for your next change. You'll be glad you did!

There are a few aftermarket oil filters that match OEM quality (like we discussed in this blog post). Yet, your safest bet is to use an OEM filter each and every time.