The following article gives detailed instructions on installing a performance cold air intake into your BMW E36 3 series car. Even though we have used a 1996 BMW E36 M3 to perform this installation, this article can be applied to any BMW E36 with a six cylinder engine manufactured from 1990-1998, including the 323i, 325i and 328i models with minor modifications.
A BMW E36 cold air intake with ASC delete is the quickest way to add horsepower and an intimidating sound to your BMW E36 engine.
Probably the biggest question that plagues BMW E36 owners is how to gain more horsepower from their engine without spending a fortune. After getting humiliated in our beloved BMW Repair Guide 1996 E36 M3 at a recent track event (by a new Suburu STI none the less), we decided it was time to let go of our purist values and start making some engine modifications. Our goal: how could we produce affordable horsepower using easy to install parts that were reversible if we decided to return the vehicle to its original specifications? The quickest solution was to get a higher flow of oxygen to the cylinders by installing a BMW E36 cold air intake and deleting the vehicle’s Automatic Stability Control. Adding a new high volume silicone intake boot would complete the improvements. Sounds difficult? Not at all. It can be easily done in your garage without the need of hiring an expensive mechanic.
The stock air box and air filter on a BMW E36 3 series car are power robbing parts that deprive your cylinders of precious oxygen needed to produce power. It’s a simple fact that pumping more air into your engine produces more power. But adding a BMW E36 cold air intake is worthless if the increased air flow you are producing is restricted or impeded. That is where the ASC delete comes in to play.
The BMW Active Stability Control system was developed as an early stability/traction control for vehicles and has since been replaced by more sophisticated systems. In general terms, BMW’s ASC is a secondary throttle body that is controlled independently of the main throttle body. Unlike your main throttle body which is controlled by your foot pressing on the accelerator, the ASC throttle body is controlled by your BMW’s DME (your engine’s computer module). The ASC is installed so air must first flow through it before it enters the main throttle body. When the car senses a loss of traction the ASC throttle body will close, shutting down power to the engine (regardless of what the driver is doing with their foot on the accelerator) until traction is regained. The problem with the ASC is that it restricts the amount of air entering the engine…even when it is in the open position. To truly gain the full performance of a BMW E36 cold air intake, the ACS throttle body must be removed and the stock intake boot replaced with a high performance silicone version. And as stated earlier, all of these changes are completely reversible if you wish to return to your stock configuration…just make sure to keep your parts.
What brand cold air intake should I install?
As is with most aftermarket performance parts, that question is dependent on many factors. If you are modifying your car for your own personal driving enjoyment without any intent of entering it into a car show or selling it as a high end restomod, you really only need to answer two questions: how much will my budget allow me to spend, and is the intake manufactured by a reputable company with a history of producing high performance racing parts.
Since our budget was around $500, our choice without any hesitation was the AFE Power Magnum FORCE Air Intake System with a Mishimoto silicone intake boot. In fact, even if our budget ceiling was $1000, we would have purchased the same system. AFE Power is a proven brand that has been used by many race teams including one of the Repair Guide’s favorites…Turner Motorsports. Mishimoto is also a proven brand used on countless race cars around the world. Together they create an awesome setup for about five hundred bucks. AFE makes both an oiled and dry intake filter for the Magnum FORCE Pro…they both work equally well and it’s just a matter of personal preference.
1. BMW E36 cold air intake (required) – Choose from one of the following cold air intakes depending on personal preference; the AFE Pro 5R with an “oiled” intake filter or the AFE Pro Dry with a maintenance free dry filter. Both units deliver an increased air flow of 80% and up to a +20hp and +25lb/ft increase in horsepower and torque.
2. Silicone intake boot (required) – For your engine to receive the full benefits from the cold air intake, you must install a performance intake boot. Mishimoto silicone intake boots provide dramatic improvements in air flow which equals more power. Which Mishimoto boot you need to order depends on what size mass air flow (MAF) sensor is attached to your intake boot (either a 3″ or 3.5″). If you are not sure what your car has, remove your intake boot from the MAF and measure the diameter of its opening before ordering below.
For vehicles with a 3″ MAF:
For vehicles with a 3.5″ MAF:
3. ASC delete intake boot plug (required) – When deleting the ASC from your BMW E36, you must plug the empty port in the intake boot. The following aluminum plug has been custom manufactured to be a perfect fit in your new silicone intake boot.
4. Performance European Spec Set Headlights (optional) – Since you will be removing your right headlight to install the cold air intake, now is a great time to upgrade your old E36 headlights to a European Spec Set version. The original plastic USA spec E36 headlights have always been considered an inferior product, offering sub-standard lighting and the tendency to scratch and yellow over time. European spec headlights are clear glass, offering superior road visibility and a performance look to your E36 3 series car. They are very easy to install…now is the time to do it!
Installation of the AFE Power Magnum Force cold air intake, Mishimoto intake boot and ASC (Automatic Stability Control) delete.
The AFE Magnum Force cold air intake is a “bolt on” performance product that takes the place of your stock air box. But “bolt on” can be misleading – bolt on simply means there is no cutting or special fabrication needed to fit the product. It does not mean that it is going to simply drop in the engine compartment, everything will line up perfectly and you will be done in 10 minutes. To make matters worse, the AFE Magnum Force instructions are generic and vague. To help our readers, we completely installed the AFE intake and Mishimoto intake boot, road tested it, then completely disassembled it to document and photograph our instructions.
Preparing the vehicle for installation includes removing the stock air intake assembly and the Active Stability Control throttle body.
- Loosen the front left headlight by removing the four 8mm bolts. Three of the bolts are on the front of the frame…the fourth is behind the light near the radiator. A neat trick is to insert a little blue tape in the end of your socket…this will help you get the fourth bolt out without dropping it. When the bolts are removed, pull the left yellow parking light out and rotate the headlight enough so you can get behind it. You do not need to remove the headlight completely (see image).
- Take out the stock air box (air filter) assembly from the vehicle by removing the two 10mm bolts and unclipping it from the MAF. These are expensive parts that are becoming more difficult to find, so we would suggest storing in the event you revert back to a stock configuration some day (trust us…you will curse yourself if you don’t).
- Unplug the wiring connector from the MAF (Mass Air Flow) sensor. Loosen the hose clamp that connects the MAF to the stock intake boot, then remove the MAF from the vehicle. Be careful with the MAF…it is a precision part that will break if dropped. Store in a safe place until reassembly.
- Loosen the hose clamp that connects the stock intake boot to the ASC throttle assembly. There is a hose that is attached to the bottom of the stock intake boot; this is the ICV (Idle Control Valve) hose. CAREFULLY remove the hose off of the stock intake boot then pry loose the plastic hose connector. We say “carefully” because you want to avoid any breaks in the hose connector or tears in the hose. We will be using the stock hose and connector again during reassembly.
- Remove the throttle cable from the top of the ASC throttle body. The throttle cable removes very easily; just create slack in the cable by “closing” the throttle plate then pop the cable loose (see image below). Tuck the throttle cable neatly away (next to the brake fluid reservoir is a nice spot) if needed in the future.
- Unplug the wiring connector from the ASC throttle body and tuck away with the throttle cable for future use if necessary. Remove the throttle body’s two mounting bolts. Grasp the ASC throttle body and remove from the vehicle, along with its rubber gasket. Once again, this is an expensive part that we suggest storing away (with the mounting bolts…just tape to side) in case you want to revert back to your stock configuration some day.
- Preparing the intake boot for installation – there are two vacuum ports on the bottom of the intake boot. Since our BMW E36 only uses one vacuum port for the ICV (Idle Control Valve) hose, the other port will need to be plugged. It is very important that the correct port is plugged so the ICV hose fits in the next step. You will need to plug the port closest to the main throttle body. Insert the plastic ICV hose fitting in the remaining second port – swivel it till it’s pointing towards the rear of the vehicle.
- Install the ICV hose to its plastic fitting on bottom of intake boot. Even though the fitting is “barbed” for a pressure fit, we like to add a hose clamp for added security. Tighten ICV hose clamp securely. Slide the large hose clamp from the stock assembly onto the end of the Mishimoto boot and attach to the main throttle body. DO NOT tighten any hose clamps yet. Everything (except the ICV hose clamp) will be tightened down at the end of the installation.
- Prepare the AFE Magnum Force intake for installation by assembling exactly as shown in the following images; make sure the filter hose clamp is positioned as shown so it can be tightened after installation. If you read the assembly instructions included with the intake, you may notice there is one major difference between ours and theirs; we mount the intake pipe assembly to the inside of the heat shield…not the outside. This will allow just enough space to fit the Mishimoto boot and allow the mounting holes to line up. Do not tighten any of the nuts or the filter hose clamp yet.
- Install the rubber reducer (included with your AFE intake) into the end of the intake pipe as shown in the following images. This reducer is needed so the stock 3″ MAF will fit snugly. If your car is equipped with an aftermarket 3.5″ euro MAF, the reducer won’t be needed.
- Install the MAF into the silicone intake boot, then maneuver the cold air intake assembly into place in the engine compartment. It helps to tilt the front end of the assembly down when installing.
- Connect the MAF to the BMW E36 cold air intake assembly. Now you can “tweak” all of your connections to make sure everything lines up nicely. The AFE intake assembly should fit snugly in the engine compartment with the cone facing down and clear of any obstructions (see image below). There may be very slight pressure between the assembly and the top radiator hose; this is perfectly fine as long as it is not pinching the hose.
- Insert a bolt with two washers in right cruise control mounting bracket. Hand tighten only. If your car has cruise control like ours, note the mounting location of the module in the image below.
- The final mounting bolt is, as with all repairs, the hardest to install. Please use patience getting it in. If you get upset trying to install it…walk away for 5 minutes and try again. It is located behind the front right headlight that we removed in Section 1 of this article. There is a small white plastic spacer that should have been included in your AFE intake kit…this spacer must be installed between the steel headlight frame and the cold air intake heat shield. When you have the spacer in place, install a bolt with two washers and hand tighten.
- Tighten all of your bolts and hose clamps. Be careful not to miss any. We started at the front of the intake and made our way back to the throttle body. It is very important that all of your intake pipes are lined up correctly and tightened down….any air leaks will cause error codes and a decrease in performance.
- Install the rubber seal on top edge of heat shield. Trim as needed with a razor blade and wire cutter (seal has a metal wire that runs inside of the rubber to help it keep its shape).
- Reinstall the left front headlight following the reverse instructions in Section 1 of this article.