Worried that your oil filter may have gotten clogged up? You came to the right place. This diagnostic guide will help you determine if you need a new oil filter. The easiest DIY way to check your oil filter is to look at the oil dipstick and evaluate the state of the oil. If you think that this is something you can do on your own, this diagnostic guide is just what you need.
What are the Signs of a Bad Oil Filter?
When an oil filter gets too dirty, it stops filtering the oil and lets it through to the engine via the bypass valve. When dirty oil that contains harmful contaminants runs through the engine, a bunch of engine problems can crop up. These include:
- Sluggish acceleration
- Dropping oil pressure
- Metallic sounds coming from the engine
- Sputtering engine
- Black or dirty smoke coming out of the exhaust
- Burning oil smell
- Grinding metallic sounds
The most obvious way to check your oil filter would be to pull it out and then visually inspect it (like you would with an engine air filter). However, that’s actually not a good thing to do. Oil will leak everywhere and you won’t be able to see the filter that well anyway.
The only way to determine if your oil filter needs to be replaced is to check the oil. If the oil still looks clean, then the filter is still doing its job. So if you notice a few of the aforementioned symptoms in your Subaru, it’s worth taking a few minutes to check the oil.
Checking the Oil Dipstick: What to Look For
Park your car on a flat, level surface. Turn off the engine and let it cool. Open the hood and then find the dipstick. Pull it out and then wipe the oil from it with a rag. Put the dipstick all the way back in and then pull it back out. Observe both sides of the dipstick.
You should be looking at two things:
1. The Oil Level
On the dipstick are two markings. These markings could be pinholes, crosshatches, the letters L and H, the words MIN and MAX, or something else. The area between both markings indicates an acceptable oil level. If the oil on the dipstick either exceeds or falls below the markings, then the oil level is too high or low, respectively.
If the oil level is low, then there may be an oil leak somewhere. Check all of the places where oil might leak out, including:
- Front main seal
- Rear main seal
- Timing cover
- Oil drain plug
- Oil pan gasket
- Valve cover gaskets
- Oil filter mount
If you can’t find an oil leak, then it’s possible that the engine is just burning the oil. This is quite common in older vehicles, actually.
The oil level doesn’t really indicate the state of the oil filter, but it’s always helpful to check it to ensure the health of your engine.
2. The State of the Oil
More specifically, look at the color and the consistency of the oil.
If the oil is thick and dark, then it’s loaded with dirt and contaminants. It’s a good indicator that the oil filter is no longer working and is letting oil through to the engine via the bypass valve. If the oil is still runny, but it’s dark, then it’s probably nothing to worry about because additives can turn the oil dark. Dark brown oil is usually okay, while black oil is bad.
Ultimately, the consistency of the oil is more telling than its color. Thick and sludgy oil is a surefire sign that the oil filter is too clogged to work properly. If you think you need to change the filter, you also should change the oil.
If it turns out that you need to replace your oil filter, we have good news for you: you can score genuine OEM Subaru oil filters at wholesale pricing on our website! Not only that, but also we offer free parts lookups and fast shipping. Get your replacement oil filter today!