After market High Flow cotton fiber air filters for your Jeep can deliver a marked improvement in the performance and mileage on your 4.0 liter Jeep engine.
It is exciting to add something to your Jeep that can help improve your performance and your mileage at the same time, and the newer after market high performance air filters can be just the answer you were looking for. There is however one thing to consider before taking the plunge and that is the fact you will have to do some maintenance on your new air filter in order to keep it performing at its rated design potential.
I have installed these high flow reusable air filters a few years ago and find that they have been an exceptional addition to both my 1995 Jeep Grand Cherokee, and my 1997 Jeep Wrangler. The only thing you need to do with this filter is to clean and re-oil them at least every three months, more often if you live in a dusty area and if you are a high mileage user. I find that it is easy to just plan on doing this filter cleaning whenever I change the engine oil.
The companies that make these air filters also offer cleaning solutions which typically come in a spray can which to me is just too costly. In my experience these sprays do not reliably clean out all of the dirt as well as I would have hoped. The spray cleaner and oiling spray cans are messy to use and I did not like the smell last time I used them. So I have been cleaning these air filters in a mild dish soap solution with warm water and follow this by a thorough warm water rinse. The primary objective of this cleaning is to remove all the oil and dirt which has collected since the last time you cleaned the air filter. This soapy warm water method is the best way that I have found for getting all of the dirt particles out without ruining the cotton fiber membrane.
This cleaning process takes about 20 minutes, and the drying step can take hours whether you use soap and warm water for cleaning. If you use the spray cleaners then it is going to take about the same amount of time since you still have to rinse the spray cleaner off with water.
So where do you begin?
First you have to remove the filter from the vehicle. My after market Air filters are held in place by a large screw clamp that takes a flat screwdriver or a 5/16″ nut driver. Next with warm water running over the filter you need to rinse off as much of the loose dirt as you can. Then take a small wash tub or bucket and put in about a gallon of warm water with about 3 tablespoons of liquid dish soap. Stir the warm water up thoroughly and swish the filter through the soapy solution then submerge it for at least 10 to 15 minutes. This will allow the dirt and grime which is embedded deep into the cotton fiber filter to really work its way loose.
After soaking the filter for a reasonable amount of time I will then swish it through the solution a few times to make sure that it is thoroughly cleaned. Next you will need to gently rinse away all of the soap, oil, and dirt with warm water. Once the filter is rinsed really well then you will need to dry it out completely. This is best done outside in the sun but as an alternative you could dry it the way I do by using a hairdryer or by placing it on your boot and shoe dryer in your laundry room. While you may be tempted to hasten the drying process by blowing on the filter with compressed air, this is not recommended and will probably ruin the filter element if you do try this method.
Okay I washed, rinsed, and dried it now what?
Once you have the filter thoroughly dry it is time to apply a light coat of thin oil. I prefer to use very light multipurpose oil because it is inexpensive and seems to be working fine on these filters that I have been using for a couple of years now. Each filter manufacturer will insist that theirs is the only oil to use and for the purist with deep pockets it is acceptable, but for those of us on a tight budget then using a light, thin, and cheap oil works fine. The entire idea of the oil is to create a sticky place for the dirt particles to collect, and yet still allow for a high flow of air through the filter.
The trick to this oiling procedure is to apply a very thin coating of oil to every inch of the filter surface. If you go slowly and are careful you will notice that the oil soaks into the fiber and spreads out for you so holding the filter such that the oil can run down into the grooves starting out at the peaks will likely yield your best results.
Checking the Oil
Once you think the filter is coated evenly take it to a brightly lit area and look through it from the center hole looking for brighter spots of light that may indicate less oil in that area. You can put a drop or two here and there to even out the coating. Now go and install the clean filter and then monitor your fuel mileage for the next few weeks to see that you are getting the best possible performance out of your air filter.
Checking this oil coating after you run the car for a few days is also a wise move. Once you see how simple this cleaning process is you will wonder why you waited so long to upgrade your air filter. Improved fuel mileage alone typically pays for these upgraded high flow air filters inside the first three months!