Clogged air filter#

(adapted from Wikipadia)

General#


clogged air filter

The (combustion) air filter prevents abrasive particulate matter from entering the engine's cylinders, where it would cause mechanical wear and oil contamination.

Most fuel injected vehicles use a pleated paper filter element in the form of a flat panel. This filter is usually placed inside a plastic box connected to the throttle body with an intake tube.

Older vehicles that use carburetors or throttle body fuel injection typically use a cylindrical air filter, usually a few inches high and between 6 and 16 inches in diameter. This is positioned above the carburetor or throttle body, usually in a metal or plastic container which may incorporate ducting to provide cool and/or warm inlet air, and secured with a metal or plastic lid.

Typical Symptoms#


Typical symptoms for a clogged air filter are for example: Driving, unsteady idle speed and weak acceleration, but also problems when starting the car starting problems and an increased fuel consumption (based on average mileage) and the currently measured mileage or abnormal exhaust fumes.

A typical starting problem which is connected to this problem is a barely or not starting engine in combination with a starter that turns over.

A clogged air filter can cause black exhaust fumes which will turn the color of the exhaust pipe to sooty black.

IF
Driving
=
weak acceleration
AND
Mileage evaluation
=
increased
THEN
"Clogged air filter"
= P5
IF
Driving
=
unsteady idle speed
THEN
Clogged air filter
= P4
IF NOT (
Driving
=
unsteady idle speed
OR
Driving
=
weak acceleration
)
THEN
Clogged air filter
= N5
IF (
Exhaust fumes
=
black
AND
Fuel
=
unleaded gasoline
)
THEN
Clogged air filter
= P5
IF ((
Engine start
=
does not start
OR
Engine start
=
engine barely starts
)
AND
Starter
=
turns over
)
THEN
Clogged air filter
= P4
demo

Repair Instructions#


aif filter change

A clogged air filter needs to be replaced by a new one. Therefore, the air filter housing have to be found. It will be either square (on fuel-injected engines) or round (on older carbureted engines) and about 12 inches (30 cm) in diameter.

After locating the housing the screws or clambs on the top of it have to be removed. Now the old air filter can be removed. At this point the housing should be cleaned from any dirt and debris with a clean rag.

Finally the new air filter can be put in and the top of the housing can be screwed or clambed back on.

IF
Driving
=
weak acceleration
THEN
Clogged air filter
= P5
IF NOT (
Starter
=
turns over
)
THEN
Clogged air filter
= N6
IF
"Check: Air filter."
= ok
THEN
Clogged air filter
= N7
IF
"Check: Air filter."
=
not ok
THEN
Clogged air filter
= P7
IF
Exhaust pipe color evaluation
=
abnormal
THEN
Clogged air filter
= P5
IF
Exhaust pipe color evaluation
=
normal
THEN
Clogged air filter
= N5
IF NOT (
Exhaust fumes
=
black
)
THEN
Clogged air filter
= N5
IF
Mileage evaluation
=
slightly increased
THEN
Clogged air filter
= P3
IF
Mileage evaluation
=
normal
THEN
Clogged air filter
= N4
IF
Mileage evaluation
=
increased
THEN
Clogged air filter
= P4
IF NOT ((
Engine start
=
does not start
OR
Engine start
=
engine barely starts
)
)
THEN
Clogged air filter
= N4
demo