Pelican Parts
BMW Parts Catalog Accessories Catalog BMW How To Articles BMW Tech Forums
Call Pelican Parts at 888-280-7799
Get FREE Ground Shipping with the purchase of $75 in qualifying parts!

Pelican Technical Article:

Cold Air Kit Installation On The BMW E30 3 Series
Jared Fenton

Difficulty Level: 3
Difficulty scale: Adding air to your tires is level one
Rebuilding a BMW Motor is level ten

     One of the most popular upgrades out there today is to install a cold air kit or cone filter on your car. The benefits of this include a small horsepower increase and a really nice growl when you accelerate. In this tech article we will discuss the installation of a cone filter on the BMW E30 3 Series. In this case we are using my 325is for the installation, however this article applies to all BMW models in general. I am using a K&N cone filter assembly for this installation. K&N filters are a great upgrade for your car. They allow more air to flow through the filter than the stock unit and are designed to be cleaned and re-used rather than the stock filter, which you use once and throw away. K&N filters use an oil filtration design, which means that you oil the filter, and particles of dirt and grime get caught in the oil. When you have to clean the filter, you simply clean out all the old oil, then re-oil the filter. 

     In this case the filter comes already pre-oiled, so all we have to do to it is put it on. The first step is to locate the stock air box in the front of the car on the driverís side. First, you will want to loosen the hose clamp on the back of the airflow meter, shown here. Once loose, carefully remove the rubber intake boot from the airflow meter. Next, find the electrical connector on the airflow meter, press the metal clip in and pull the connector off.

     Next, remove the two 10mm nuts securing the air box to the bracket shown here. Once removed, slowly lift out the air box to the rear. You will now see a small tube in the front of the air box. This is the snorkel that takes incoming air from in between the headlights. Carefully disconnect this snorkel from the air box then lift the whole air box assembly out of the car.

     With the air box out of the car, undo the metal clips around the air box and remove the upper portion that the airflow meter is connected to. We will have to remove the airflow meter from this piece to continue. With the upper portion removed, you will now see a baffle inside the filter. Remove this baffle and you will see four 10mm nuts that hold the airflow meter to the air box. Remove these nuts. The airflow meter will now be free of the air box. Be sure that you also remove the small gasket in between.

     Now, find the adapter piece that is included in the cold air kit. We will need this piece so that we can mount the cone filter directly to the airflow meter. Simply place the gasket over the studs on the airflow meter, and then place the adapter piece over the gasket. Re-install the four 10mm nuts and tighten. The final result will look like this.

     Next, go back to the car and place the airflow meter back into the intake boot and tighten the hose clamp, securing it in place. Re-connect the electrical connector on top by pushing it on while holding the metal clip in.

     Take the cone filter, and place the included hose clamp around the outside of the rubber lip on the back. Now slide the cone filter over the adapter piece on the airflow meter and tighten the hose clamp.

     Now we need to secure the filter assembly to the bracket that once held the air box. I simply used two zip-ties threaded together in a loop around this bracket to hold it in place. Tighten the zip ties and cut off the remaining plastic.

     Now we will also need to secure the cruise control actuator as shown here. With the air box removed, the stud that once held the actuator is missing and the actuator is only held at the bottom. Simply use a small 10mm bolt, slide it through the bracket, and then re-install the 10mm nut on the other end. This will secure the actuator.

This shows this final result.

And thatís it, youíre done!

     Just another note, the cold air kit does not include a heat shield. The purpose of a heat shield is to deflect the hot air from the radiator from entering the filter. I am currently in the process of developing a heat shield for the filter using sheet aluminum and portions of dryer ventilation. I will have my results posted soon.

     After installation, I noticed the results immediately. Through the midrange, the car pulls harder, and Iíve noticed that the car runs slightly cooler as well. Sound wise, it really makes a difference. Before the installation, the intake noise was very quiet and subdued. Now, there is a loud growl coming from the engine when you step on the gas.  

     Well, there you have it - it's really not too difficult at all.  If you would like to see more technical articles like this one, please continue to support Pelican Parts with all your parts needs.  If you like what you see here, then please visit our online BMW catalog and help support the collection and creating of new and informative technical articles like this one.  Your continued support directly affects the expansion and existence of this site and technical articles like this one.  As always, if you have any questions or comments about this helpful article, please drop us a line.

Comments and Suggestions:
Gary Comments: This is written as if there were pictures or diagrams included but I don't see any
September 7, 2011
  Followup from the Pelican Staff: There were no pictures with the article. Thanks for the feedback. Glad we could help.
- Nick at Pelican Parts

Got more questions?  Join us in our BMW Technical Forum Message Board, and ask a question to one of our many automotive experts.
About Us
Pelican Parts, LLC
1600 240th Street
Harbor City, CA 90710
Order Online or Call:
Sign Up for Pelican Pit Stop News & Special Offers