Oil leaking from oil filter

Most common causes of oil leaking from oil filter

If you’ve just done an oil change and notice oil leaking from the oil filter, chances are you failed to remove the old oil filter gasket or the filter is over/under tightened.

#1 cause — leaving the old gasket in place

When you remove an oil spin-on filter, the old gasket can sometimes sticks to the oil filter mounting boss. If you don’t remove the old O-ring before installing the new filter, you’ll wind up double gasketing the oil filter, guaranteeing an oil filter leak.

#2 cause of oil filter leak — under-tightening

The gasket must compress in order to seal the filter and

Under-tightening is a common cause of oil filter leaks

prevent leaks. Most filter manufactures include tightening instructions right on the filter box. Those instructions usually call for you to spin the filter on until it contacts the mounting base and then turn the filter a specified number or turns by hand. The turns vary based on the gasket design.

#3 cause — over-tightening

Some oil filter gaskets are square-cut O-rings, while others are traditional rounded-edge O-rings. It doesn’t take must torque to seat and seal either type. However, it’s much easier to split/crack a rounded O-ring, causing an immediate oil leak. Never use an oil filter wrench to tighten a spin-on oil filter.

Over-tightening can damage the O-ring used to seal the oil filter to the oil filter housing

Old oil cooler gasket can look like a filter leak

If your engine has a turbo-charger, it most likely has an oil cooler as well. In many cases, the carmakers simply add an oil cooler between the oil filter housing and the oil filter.

The oil cooler-to-oil filter housing usually contains a gasket and that gasket can leak over time. The oil drips down and looks just like a leaking oil filter.

If you’ve changed the filter and tightened it properly but still get an oil puddle on the ground, check for a leaking oil cooler gasket.

Diagnose an oil cooler gasket leak

Spray the entire oil filter/cooler area with brake cleaner.
Dry with compressed air.
Install a new filter
Puff baby powder around the oil filter housing, oil cooler and oil filter gasket areas.
Drive the vehicle and check the powdered areas in a few days to find the source of the leak.

Typical oil cooler location

©, 2021 Rick Muscoplat