Pelican Technical Article: Replacing the Air Filter Wayne R. Dempsey
Time: 15 min
Tab: $40
Talent:
Tools:
Applicable Models:
911 (1965-89) 930 Turbo (1975-89)
Parts Required:
New air filter
Hot Tip:
Replace your air filter every 10,000 miles
Performance Gain:
Better airflow into your fuel intake system
Complementary Modification:
Install an aftermarket air filter, replace your CIS air box straps
This article is one in a series that have been released in conjunction with Wayne's book, 101 Projects for Your Porsche 911. The book contains 240 pages of full color projects detailing everything from performance mods to changing your brake pads. With more than 650+ full-color glossy photos accompanying extensive step-by-step procedures, this book is required reading in any Porsche 911 owner's collection. See The Official Book Website for more details.
Check out some other sample projects from the book:
Every 10,000 miles or so, you should change the air filter in your 911. The air filter protects the fuel injection system and the air intake system from dust and debris that can be sucked in under normal operation.
On the early 911s, the circular air filter was contained in a housing that spanned the top of the carburetors or the Mechanical Fuel Injection (MFI). To replace the air filter, you simply disconnect the long snout on the air filter housing, and remove the old one. Make sure that you dont drop any of the attachment screws into the engine compartment: they can be very difficult to fish out. The new air filter must be aligned properly within the housing in order to replace the snout on the air cleaner.
With the introduction of the Continuous Injection System (CIS) on 911s starting in 1973, Porsche implemented a new type of air filter. The CIS air filter is contained within the plastic air cleaner housing and held on with flexible rubber straps. Simply detach the straps at the top of the air box, and remove the filter from the air intake housing. Check the rubber straps to make sure that they arent cracked and worn out. Replace them if they show signs of wear or age.
On the 1984 and later 911 Carreras, Porsche implemented the Motronic Fuel Injection system, which uses a square air filter that is mounted on the right side of the engine compartment. The filter is located in the intake system inside a box held on with clips. Simply remove the clips to replace the air filter.
If you talk with people familiar with performance cars, you will no doubt hear discussions on the different types of air filters used in cars. For the 911 there are basically two different types of air filters: the stock paper or cloth air filters and aftermarket units. These aftermarket units utilize an oil-soaked fabric to achieve freer air flow. While this may sound good, many aftermarket filters also do not filter as well as the stock units. In addition, the various horsepower claims of some aftermarket filters are somewhat suspect as well. The bottleneck for air flow in the 911 engine is not the air filter. The primary advantage of the aftermarket units is that you usually only have to purchase one, and it will last the life of your car. The bottom line is to carefully research any aftermarket filter before you install it to your car. Make sure that it filters as well or better than the original Porsche specifications for your year car.
Figure 1
On the early cars, the air filter housing covered the Mechanical Fuel Injection system or carburetors. The circular air filter is located inside the housing, and is accessed by removing the long snout of the air cleaner housing. You dont need to remove the retaining screws to replace the air filter. Simply loosen them up and rotate the snout until it comes off.
The CIS cars (1973 ½-1983) house the air filter underneath a plastic air intake housing. This housing is held onto the CIS air box by two rubber straps. Access to the filter is gained by disconnecting the straps and removing the housing. Inspect the straps when you remove the filter, as these have a habit of breaking when they age.
The Carreras (1984-89) and 911 Turbos housed their air filter in a box on the right side of the car (see orange stripe). This box is held together with clips (indicated by arrow). To replace the air filter, simply unsnap the metal clips and pull out the old filter.
Comments: tell folks to get their wives' very small hands to reach around to the front of the air box to release the clips on the 84 - 89 Carrera! German mechanics are either all women or just have really small hands! There are so may spots I can't reach but my wife can. Good thing this is her babay!
March 4, 2012
Hennessy
Comments: tips on how to change air filter on 997 S
March 2, 2012
tom
Comments: how do i change front break pads on a 2003 porsche 911, thanks in advance
February 10, 2012
Check out some other sample projects from the book:
