Jeep Cherokee Forum

Jeep Grand Cherokee 1993-2004: How to Replace Oil Pump

Has the old oil pump on your Jeep Grand Cherokee kicked the bucket? Before you shell out big bucks to your local shop to replace it, check out our DIY guide and save those hard earned dollars.

By Brett Foote - October 14, 2015

This article applies to the Jeep Grand Cherokee ZJ/WJ (1993-2004).

The oiling system in your Jeep's engine is crucial in keeping it running. Without engine oil, there is no lubrication inside the motor, meaning that things go metal-on-metal, which is bad. The performance of your engine's oiling system can be measured in terms of oil pressure. If the pressure is too low, the oil cannot make its way through all of the oiling passages and valve train, resulting in engine damage. The oil pump is the critical component in oil pressure, as it helps press oil through the motor. With the pump, you'll likely have insufficient oil pressure to keep the engine running safely. If your oil pressure is dead in the water, it's time to replace the pump.

Materials Needed

  • Floor jack or ramps
  • Jack stands
  • Wheel chocks
  • Assorted common wrench sizes
  • Ratchet and common socket sizes
  • Oil drain pan
  • Rags
  • Torque wrench

Step 1 – Lift up the front end

Jack up the front of the Jeep with a floor jack and place it on jack stands, or, alternatively, drive it up on a pair of ramps. If you use a jack and jack stands, be sure to set the emergency brake and chock the wheels so it doesn't roll.

Figure 1. Lift up the front of the Jeep and place it on jack stands, or use a pair of ramps to lift it up.

Step 2 – Remove oil pan and other components

To remove the oil pump, you must first remove a number of other components. Remove the oil drain plug and drain all the oil in a catch can or other container. Remove the oil pan bolts and the four bolts holding the crossmember in place. Remove the crossmember and the oil pan. Next, remove the timing chain cover, then the timing chain and tensioners.

  • Figure 2. Drain the oil.
  • Figure 3. Remove the crossmember bolts and crossmember, then the oil pan bolts and oil pan.
  • Figure 4. Remove the timing chain cover, timing chain, and tensioners.

Step 3 – Remove oil pump

Remove the bolts holding the oil pump in place, then remove the oil pump. Clean any spilled oil from the surrounding cables with some rags.

Figure 5. Remove the oil pump.

Step 4 – Install new oil pump

Insert the new oil pump in the same position the old oil pump was installed. Reinstall the oil pump bolts and torque them to 21 ft/lbs. Reinsert the tensioners and reinstall the timing chain. Replace and reinstall the timing chain cover. Set the oil pan back in place and reinstall the bolts that hold it in place. Replace the crossmember and reinstall the four bolts. Be sure that the oil drain plug is installed, and then fill the Jeep back up with oil. Start it up and check for any leaks before test driving.

Related Discussions