Why Is My Oil Filter Leaking?

Your engine needs oil to run, and even with frequent changes, it’s possible for debris and impurities to find their way into the lubrication system over time and wreak havoc. That’s where the oil filter comes in.

Filters protect your engine from major damage and provide an easy point of maintenance that can extend the life of your vehicle by years if they receive proper attention. An oil filter leak can compromise these gains, but if you understand what causes a leak and how to avoid it, you can take steps to keep your engine in prime condition longer.

Clean motor oil is important because if the oil were left unfiltered for a period of time, it could become saturated with tiny, hard particles that can wear surfaces in your engine. This dirty oil can wear the oil pump’s machined components and damage the bearing surfaces in the engine.

How do oil filters work?

The outside of the filter is a metal can with a sealing gasket that allows it to be tightly held against the engine’s mating surface. The base plate of the can holds the gasket and is perforated with holes around the area just inside the gasket.

A central hole is threaded to mate with the oil filter assembly on the engine block. Inside the can is the filter material, most frequently made from synthetic fiber. The engine’s oil pump moves the oil directly to the filter, where it enters from the holes in the perimeter of the base plate.

The dirty oil is passed (pushed under pressure) through the filter media and back through the central hole, where it re-enters the engine.

Why Is My Oil Filter Leaking

Choosing the right oil filter

Choosing the correct oil filter for your vehicle is of the utmost importance. Most oil filters look very similar, but small differences in the threads or gasket size can determine whether or not a particular filter will work on your vehicle.

The best way to determine which oil filter you need is by consulting your owner’s manual or by referencing a parts catalog. Using the wrong filter can cause oil to leak out of the engine, or an ill-fitting filter could just fall off. Either of these situations could lead to serious engine damage.

Why Is My Oil Filter Leaking?

An oil leak can leave a few drops or a big puddle under your engine. Ignoring a leaky oil filter can quickly lead to expensive engine damage.

There are seven common reasons why an oil filter leaks. Knowing the possible causes will help you determine what steps you should take to correct the problem.

Double Gasket

The most common mistake is the dreaded oil filter “double gasket.” This happens when an oil filter is replaced. The old filter gasket sticks to the engine, and the new oil filter and gasket are installed on top of the old one.

After removing the old filter, check that its gasket is still mounted on the filter. If you accidentally double-gasket an oil filter, hopefully, it will blow out (creating a nasty mess) as soon as the engine starts and not as you’re driving down the road.

Worn Valve Cover Gasket

Your car’s engine may have one or two valve gaskets that create a seal between the valve cover on top of the engine and the upper part of the cylinder head. If this valve cover gasket becomes worn, it could fail to keep oil from leaking.

The valve cover gasket can also harden and develop cracks over time, which can cause leaks. If you notice oil leaking from the top of the engine, it could indicate problems with the valve cover gasket. Typically, this part lasts between 20,000 and 50,000 miles before needing to be replaced.

Loose Drain Plug

A loose drain plug is another common reason your car might be leaking oil. Drain plugs, which are attached to the oil pan, allow oil to drain from the engine. If the drain plug becomes loose, the accumulated oil may leak.

If you notice oil leaking directly underneath the drain plug, this component may be causing the leak. You may also notice leaking oil soon after an oil change, which may have caused the drain plug to loosen.

Damaged Threads

An oil filter’s baseplate threads are softer than the threads on the mounting nipple and can be cross-threaded if the oil filter is screwed on crooked when it’s installed. You’ll need to install a new filter if the threads are damaged.

If you screw on the new filter without any problems, and there are no apparent oil leaks, it’s still a good idea to have your mechanic check out the filter mounting nipple threads for damage.

Faulty Oil Filter

Oil filters help the engine oil stay clean by filtering out contaminants and debris. Over time, pressure can build up in the oil filter, which can cause it to rupture and leak. Installing the wrong oil filter or failing to install it properly can also cause oil leaks. Like a loose drain plug, a faulty oil filter may become apparent after a recent oil change. Ensure the oil filter is correctly installed and sealed to prevent an ongoing leak.

Wrong Filter

Check your owner’s manual for the correct filter number for your specific engine. A filter may feel as though it is tight when installed, but the threads may not be exactly the same as the mounting nipple. This will cause the filter to loosen up and leak over time.

Also, the wrong filter may have the incorrect by-pass valve. The by-pass value opens to protect the engine from oil starvation if the filter becomes clogged. If you’re not sure you are installing the correct filter, leave it to your mechanic.


What to do if your oil filter is leaking?

Check the rubber mounting gasket to make sure it is not cut, nicked, twisted or damaged in any way, and is properly seated and snug in the filter baseplate. Always install a new filter if the gasket is bad.

Can you drive with leaking oil filter?

No you could not drive it without certain damage to the engine. All the oil will likely be gone in moments. Oil pumps are very good at their job and the oil filter is directly after the oil pump. Remove the filter using a tool made for the purpose, then fit a new one.

Is oil filter housing leak serious?

If you’re sure it’s actually leaking, it’s a good idea to do the repair. The potential for damage is high, and you don’t know when it will get bad enough to start dropping onto your belt. If you’re sure it’s actually leaking, it’s a good idea to do the repair.

Can too much oil cause oil filter leak?

Yes, Overfilling an engine with oil can put additional pressure on seals and, over time, can cause an oil leak.

How much does it cost to replace a leaking oil filter?

However, you might find that it develops a leak from the gaskets or it may develop a crack in the oil filter housing itself, which will require replacement. The average cost to replace the oil filter housing is $171 to $655 depending on the make and model, and a few cars may be higher than that.