How to Change the Oil in a Jeep Wrangler (JK, JL, TJ, etc.)

Changing your own oil is a simple way to maintain your Jeep, save money, and keep your engine running strong. This tutorial works for most Wranglers (TJ, JK, JL) and can be adapted for 3.6L Pentastar, 4.0L I6, and other common engines.

What You’ll Need:

1. Oil filter (check specs for your model/year)
2. Engine oil (typically 5W-20 or 5W-30, full synthetic preferred)
3. Socket wrench + oil filter wrench
4. 17mm or 13mm socket (varies by engine)
5. Oil catch pan
6. Funnel
7. Gloves + shop towels
8. Optional: New drain plug washer (for certain models)

🔎 Pro Tip: Always double-check your Jeep’s owner’s manual for oil capacity and filter specs before getting started.

Step-by-Step Instructions

✅ Step 1: Warm Up the Engine Slightly

1. Start your Jeep and let it run for 3–5 minutes to warm the oil — this helps it drain more easily.
2. Then shut off the engine and engage the parking brake.

✅ Step 2: Locate the Drain Plug & Filter

1. Slide under the engine (or use ramps or jack stands if needed).
2. Locate the oil drain plug — usually on the bottom rear side of the oil pan.
3. The oil filter may be:
4. Underneath near the engine block (TJ / older models)
5. On top of the engine (JK/JL 3.6L Pentastar — cartridge-style)

✅ Step 3: Drain the Old Oil

1. Position your oil catch pan beneath the plug.
2. Use a socket wrench to remove the drain plug — let the oil flow completely.
3. Wipe the plug clean and inspect the washer — replace if worn.

✅ Step 4: Remove the Old Oil Filter

1. For canister-style filters, use an oil filter wrench and twist off counterclockwise.
2. For cartridge filters (JL/JL 3.6L):
3. Use a socket to remove the top cap.
4. Pull out the cartridge and replace the O-ring if your kit includes a new one.
5. Drop in the new filter and reinstall the cap to spec (usually ~25Nm torque).

🧠 Don’t forget to lightly oil the gasket on the new filter before installing it — this ensures a good seal.

✅ Step 5: Reinstall the Drain Plug

1. Once the oil has finished draining, reinstall the plug snugly (don’t overtighten).
2. Wipe down any oil residue from around the pan area.

✅ Step 6: Add New Oil

1. Remove the oil fill cap on top of the engine.
2. Insert a funnel and add oil slowly, checking your capacity:
3. 3.6L V6 (JK/JL): ~6 quarts
4. 4.0L I6 (TJ): ~6 quarts
5. Wait a minute, then pull the dipstick and check oil level. Add more if needed.

✅ Step 7: Start the Engine & Check for Leaks

1. Fire up your Jeep and let it idle for a minute.
2. Check under the vehicle and around the oil filter for leaks.
3. Turn it off and check the dipstick one more time to confirm proper level.

🔁 Step 8: Reset Oil Life (If Applicable)

1. On JKs/JLs with digital displays:
2. Turn the ignition to “On” without starting the engine.
3. Use the menu buttons to find “Oil Life.”
4. Hold “OK” or “Reset” for a few seconds to clear it.

♻️ Don’t Forget to Recycle

Take your used oil and filter to a local auto parts store or recycling center — most accept them for free.

One Last Thing…

If all of the above seems like too much of a headache, you can always schedule an appointment to stop by Karnage for an oil change and a free multi-point inspection!