Jeep Cherokee Forum

Jeep Cherokee 1984-2001: How to Replace Air Filter

Is it time to replace the air filter in your Jeep Cherokee? Then continue reading for the step-by-step guide.

By Mark Garrett - September 16, 2015

This article applies to the Jeep Cherokee XJ (1997-2001).

Changing the air filter in your Jeep may be one of the easiest maintenance items you can do, and it will save you cash. Your engine is really just a big air pump that needs all the clean air it can get. Changing the filter in your Jeep is silly easy. Whether you are choosing a stock filter for $9 or a fancy one for $57, they will help your engine breath clean air and run well.

Let's take a look at what choices you have for filters, and then move on to changing the filter in your Jeep Cherokee.

Materials Needed

  • Latex gloves
  • Screwdriver
  • New filter
  • Pliers

Step 1 – Let's talk air filters

This issue is so controversial, it is a good one to start with.

Vehicles have used the same paper pleated air filters since oil bath type went away. They work very well and have different qualities. They are reasonably priced between $8 to $12. They last a year in non-severe conditions, much less if you take your Jeep off-road.

Figure 1. Pleated paper air filter.

A similar, yet really different style, is the oil cloth style such as K&N. It comes with a strong warranty and it will be the last air filter you will buy for your Jeep, but costs $57. Instead of throwing it away when it is dirty, you clean it and then re-oil the filter medium. After replacing the pleated paper style seven times, you can pay for the K&N. You do have to purchase the oil to put in it for $10. They claim increased power and mileage, too. Once again, there is vast debate on whether that is true or not.

Figure 2. K&N air filter.

Pro Tip

You can also get a cold air intake for your Jeep. They vary in style, but need to pick up cool air from outside of your engine compartment. They can help the performance of your engine; although, the stock airbox on your Jeep does a good job for what it is. Remember that since your engine is an air pump, if you put the cold air intake too low and you cross water, it can get sucked up in your engine and you will be very, very sad.

Step 2 – Remove top of filter box

The airbox is in the driver's side of the engine compartment up high.

Figure 3. Air box.
  • After you locate the box, the lid is held on with three clips. Unsnap them, but wait to pull the lid off.
Figure 4. Airbox clips (red arrows), and hose (1).
  • Next, there are two hoses on the box that have to be pulled off. One is number one in Figure 4, and the other is shown in Figure 5.
Figure 5. Hose to unplug.
  • Now remove the elbow that goes from the airbox to the intake manifold. Grasp it and wiggle it while pulling it up.
Figure 6. Air cleaner elbow at intake.
  • Now the lid of the assembly can be pulled off with a little force.
Figure 7. Remove airbox lid.

Step 3 – Replace filter element

Lift the filter up slightly and pull out. After you have it out, wipe the inside of the box clean. Install new filter like you pulled the old one out.

  • Assemble the air box and intake elbow.
  • Refit the hoses to the intake system.
  • Snap the airbox clips back on.
Figure 8. Air filter element.

Step 4 – Check if your air filter box has oil

If your air filter box has oil in it, don't freak out. The 4.0 in your Jeep is very stout, but a common issue is blow-by getting into the air cleaner assembly.

Figure 9. Extreme example of blow-by.

There are a few things that you can do to help with this. The most important is to be sure all of the crankcase ventilation hoses are in good shape and not plugged. If any of them look bad, replace them. If they are plugged, use brake or carb cleaner to open them up. If yours looks anything close to the one in Figure 9, you will probably have to pull the valve cover and clean the baffles in it.

If after all that you still have issues, there is another modification that some Cherokee folks came up with. It involves replacing the PCV hose between the valve cover and airbox with an in-line air compressor filter and filter. It looks a bit extreme, but is cheap, it works, and others may think you have a speed secret.

  • Figure 10. PCV hose mod.
  • Figure 11. Replacement PCV hose assembly.

Pro Tip

A clean and operational Positive Crankcase Ventilation system along with a clean air filter should take care of most blow-by issues.

Featured Video: How to Change Air Filter

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