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Jeep Cherokee 1984-1996: How to Repair Oil Filter Adapter Leak

The engine oil filter adapter is used to position the filter where it can be accessed easily. Engine oil can seep through very small openings, making the adapter a prime location for oil leaks. Replacing the O-rings should give you many trouble-free miles.

By Weston Chadwick - September 9, 2015

This article applies to the Jeep Cherokee XJ (1984-1996).

The oil filter adapter mounts to the engine block and is used to move the filter in-line with the engine. Mounting the oil filter directly to the engine may damage the filter as the engine moves in its mounts. If the oil filter hits the frame mount hard enough, a large leak will develop and lead to possible engine damage; hence, the need for an adapter to move the filter out of harm's way. Three O-rings seal the areas between the adapter and engine block. Make sure the new O-rings are installed correctly by smoothly tightening the oil filter adapter bolt.

Materials Needed

  • 10mm and 12mm wrench
  • T60 Torx bit
  • 13mm wrench
  • 9/16" Allen bit
  • 5/8" Allen bit (pre-90's Cherokees)
  • Flat head screwdriver or pick
  • Breaker bar
  • Drain pan
  • Rubber gloves
  • Safety glasses
  • Electrical tape (optional)
  • Brake cleaner and rags
  • Drain pan
  • Oil filter wrench pliers or filter socket caps

Step 1 – Disconnect battery

Disconnect the (black) negative battery cable. Place the cable in an area where it cannot accidentally contact the battery terminal. You can also wrap the cable with electrical tape.

Figure 1. Unhook the negative terminal.

Step 2 – Locate oil filter adapter and remove engine oil filter

The oil filter adapter is located on the passenger's side of the engine. You will see it near the bottom of the cylinder head. Depending on who tightened the oil filter, you may be able to remove it with only your hand. Place a drain pan beneath the filter. Turn it counterclockwise for removal. If it does not move, oil filter wrench pliers or filter socket caps can be used.

Figure 2. The red circle indicates the location of the oil filter adapter.

Step 3 – Remove the oil filter adapter

The adapter is in an area with little clearance. You will need a T60 Torx bit or a 9/16" Allen key and a low profile ratchet. Earlier Cherokees (pre-90's) used a 5/8" Hex head bolt instead. Some sockets use a set screw to hold the Torx bit in place. Remove the screw and/or tap the Torx bit out of the socket with a hammer and punch. A 13mm wrench can be used to turn the Torx bit as well. This bolt can be very snug. Placing a breaker bar on the end of the wrench should give you the needed leverage. Warming the engine up near operating temp may help as well. Once you fully remove the bolt, pull the adapter off the engine block. You will see two O-rings on the bolt and one large O-ring where the adapter meets the engine block. A small flat head screwdriver or pick is helpful when removing the O-rings.

  • Figure 3. Inside the red circle is the slot for the Torx bit.
  • Figure 4. The wrench and Torx bit setup.
  • Figure 5. The three oil filter adapter O-rings.

Step 4 – Install the oil filter adapter

Install the new O-rings into the adapter. Rub some oil on the O-rings to reduce the chance of tearing. Torque the oil adapter bolt between 30 to 40 ft-lbs. and re-install the oil filter.

Clean the area with brake cleaner and a rag. Hook up the battery and start the engine while inspecting for oil leaks. If none are found, drive for 20 miles and inspect the area again. If everything checks out, then you are done.

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