5.1 Air Filter

The specified maintenance intervals for the air filter are based on "normal" use. If the car is operated primarily in dusty conditions, the air filter should be serviced more frequently. A dirty air filter element starves the engine for air, reducing power output and increasing fuel consumption. Fig. 5-1, Fig. 5-2, and Fig. 5-3 show the locations of the air filter housing for the engines covered by this manual.

Fig. 5-1.

Air filter housing (arrow) for CIS and CIS-E fuel injection systems used on all 1985-1987 cars with gasoline engines, and 1988-1989 cars with 16-valve engines. The correct replacement filter element is Volkswagen part no. 113 129 620.

Fig. 5-2.

Air filter housing used on diesel engines. The correct replacement filter element is Volkswagen part no. 069 129 620.

The upper and lower parts of the air filter are fastened together with spring-clips around the outside edge. To replace the air filter element, unfasten the clips that separate the air filter housing. Take note of the filter's installed position, then remove the old filter element and wipe the inside of the air cleaner housing using a lint-free cloth. On gasoline engines, the filter element is installed with the gasket side facing up. On diesel engines, filter element is installed with the gasket side facing down. Make sure that the two halves of the air filter housing are mated correctly, and refasten the spring-clips.

Fig. 5-3.

Air filter housing for Digifant fuel injection systems used on 1988 and later gasoline engines (except 16-valve).

On California models, clean the element at the specified interval by tapping it lightly, dirty-side down, on a hard surface to remove the dirt. Do not blow it clean with compressed air, as this can cause small tears which will lead to engine contamination. Do not clean it in gasoline or cleaning solvents, and do not coat it with oil.