The 2013 Kia Optima uses a cartridge-style oil filter mounted on top of the engine
The 2013 Kia Optima's oil filter is not a spin-on canister like many older cars. Instead, it's a cartridge filter housed in a plastic cap on the top of the engine, near the front. This design is common on modern Kias and takes about 10 to 15 minutes to change once you have the car safely raised and the old filter removed.
The filter sits directly above the engine block, so you'll need to access it from above rather than from underneath. This location makes the job straightforward for most owners, though you will need an oil filter wrench to remove the cap that holds the cartridge in place.
Key Takeaways
- The 2013 Optima has a cartridge-style filter in a plastic cap on top of the engine, not a traditional spin-on filter.
- You will need an oil filter wrench (usually 74mm or 86mm, depending on engine size) to remove and reinstall the filter cap.
- The correct replacement filter part number is 26300-35503 for all 2013 Optima engines.
- Changing the filter takes 10 to 15 minutes and requires only basic tools: a wrench, an oil drain pan, and a new filter cartridge.
What size wrench you need for the filter cap
The plastic cap that holds the cartridge filter requires a specific oil filter wrench to remove. For the 2013 Optima, you need either a 74mm or 86mm wrench, depending on which engine your car has. The 2.0-liter turbo and 2.4-liter engines use the 74mm size, while the 2.0-liter non-turbo uses the 86mm.
If you don't know which engine you have, check your owner's manual or look at the engine block itself—the displacement is usually stamped on the side. You can buy an adjustable oil filter wrench at any auto parts store for $10 to $20, and it will fit both sizes. A socket-style wrench is easier to use than a strap wrench if you have the space to work above the engine.
The correct filter cartridge and part number
The replacement cartridge for all 2013 Kia Optima engines is Hyundai/Kia part number 26300-35503. This is the OEM (original equipment manufacturer) filter, which means it's made by Kia's parts division and meets the exact specifications for your car.
You can order this part from any Kia dealer, or buy aftermarket equivalents from auto parts stores under brands like Fram, Mobil 1, or Bosch. The OEM filter costs $8 to $15, while quality aftermarket filters run $6 to $12. All cartridge filters for the 2013 Optima are the same size and shape, so the brand matters less than making sure you're buying a cartridge, not a spin-on filter.
Step-by-step removal and installation
Start by warming the engine for a minute or two—warm oil flows faster and drains more completely. Turn off the engine and let it cool just enough to touch safely. Locate the filter cap on top of the engine (it's a round plastic housing about 3 inches across) and position an oil drain pan underneath it.
Use your oil filter wrench to turn the cap counterclockwise and unscrew it by hand once it's loose enough to grip. The old cartridge will come out with the cap. Pour any remaining oil from the cap into your drain pan, then remove the rubber seal from the inside of the cap and discard it. Wipe the cap clean with a rag.
Insert the new cartridge into the cap, making sure it sits flat against the bottom. Place the new rubber seal (which comes with the replacement filter) into the groove on the underside of the cap. Screw the cap back onto the engine by hand first, then use your wrench to tighten it snugly—do not over-tighten, as the plastic cap can crack. A quarter-turn past hand-tight is enough.
What to do with the old filter and oil
The old cartridge and the oil you drain are both recyclable and should never go in the trash. Most auto parts stores that sell oil and filters will take used oil and filters for free, no purchase necessary. Some will even give you a small credit toward your next purchase.
If you're changing the oil at the same time (which you should, since the filter and oil work together), drain the old oil into a container with a tight lid and take it to the same store. Many municipalities also have hazardous waste collection days where you can drop off used oil for free. Never pour used oil down a drain or into the ground.
Common mistakes to avoid
The most common error is forgetting to replace the rubber seal when you install the new filter. The seal comes attached to the new cartridge or loose in the box—check both places. If you reinstall the cap without a new seal, oil will leak around the cap and onto the engine.
Another mistake is over-tightening the plastic cap. The threads are plastic, not metal, and they strip easily if you use too much force. Hand-tight plus a quarter-turn with the wrench is the correct tightness. If you feel strong resistance, stop—you may have cross-threaded the cap, and forcing it will damage it.
Finally, don't confuse the oil filter cap with the oil filler cap (where you pour new oil in). The oil filler cap is larger and sits farther back on the engine. The filter cap is smaller and sits forward, closer to the front of the engine bay.
Frequently Asked Questions
Can I change the filter without raising the car?
Yes. The filter cap is on top of the engine and accessible from above without lifting the car. You only need to raise the car if you're also draining the oil from the pan underneath, which requires access from below.
How often should I change the filter?
Kia recommends changing the oil and filter every 10,000 miles or every 12 months, whichever comes first. If you drive mostly short trips or in dusty conditions, change it every 5,000 miles instead.
What if the filter cap won't unscrew?
If the cap is stuck, wrap a rubber band around it to improve grip, or tap the wrench gently with a hammer to break the seal. Let the engine cool completely if it's still warm. If it's truly stuck, a penetrating oil like WD-40 left on the cap for 15 minutes can help.
Is the rubber seal reusable?
No. Always discard the old seal and use the new one that comes with the replacement filter. A used seal loses its flexibility and won't create a tight seal, which causes leaks.