Answer: It's hard to give a specific time or mileage figure because the life of
the filter depends on how much crud it ingests. A filter that lasts 20,000
or even 30,000 miles on a vehicle that's driven mostly on expressways
may last only a month or two in a rural setting where the vehicle is driven
frequently on gravel roads. Changing it annually or every 15,000 miles
for preventative maintenance may be a good recommendation for the city
driver, but not its country cousin. Regardless of the mileage or time,
a filter should be replaced before it reaches the point where it creates
a significant restriction to airflow. But when exactly that point is reached
is subject to opinion. A slightly dirty filter actually cleans more efficiently
than a brand new filter. That's because the debris trapped by the filter
element helps screen out smaller particles that try to get through. But
eventually every filter reaches the point where it causes enough of a
pressure drop to restrict airflow. Fuel economy, performance and emissions
begin to deteriorate and get progressively worse until the dirty filter
is replaced. Many heavy-duty trucks have a "restriction" meter
on the air filter housing that signals when the filter is dirty enough
to need replacing. But lacking such a device, the best you can do is guess.
Removing the filter and holding it up to a light will show you how dirty
it is. If it's really caked with dirt, it obviously needs to be replaced.
Trying to shake or blow the dirt out is a waste of time because too much
of it will be embedded in the filter fibers. Note: Many filters that appear
to be dirty are in fact still good and do not really need to be replaced.
So it's up to you. If you think it's dirty, replace it. If you don't think
it's dirty enough to need replacing, then don't. |
Answer:
Even during low speed operation, the engine pulls in a tremendous volume
of air. This air has a great deal of abrasive particles, which must be
prevented from entering the engine. The air cleaner traps the abrasive
particles before they can enter the engine. In so doing, however, it clogs
itself. The air filter should be checked every other month. Cars with
fuel injection typically have an air filter element located in an air
induction assembly like the one shown below. The filter element is located
in a rectangular box called the air cleaner housing. The element may be
removed by unlatching a series of clamps or unscrewing a series of screws.
Cars with carburetors or throttle body fuel injection often have a large
round air cleaner assembly mounted on top of the carburetor. The filter
is located inside the air cleaner housing. Remove the top of the air cleaner
by taking off a single wing nut as shown below. To inspect or change the
air filter element:
1.
First loosen and remove the latches, screws, or wing nut. Remove the cover
and then the air filter element.
2. Carefully inspect the air filter element. You will find dirt and oil
on one side of the filter element. This material has been trapped by the
filter material. Any dirt and oil buildup on the filter means it should
be changed.
3. Place the new filter element next to the old one on the work bench.
Carefully compare the two filter elements. Both must have the same dimensions.
The gaskets on the top and the bottom of the filter elements must be exactly
the same.
4. Place the new air filter element in the air filter housing . Make sure
the gasket surface is aligned on both the top and bottom.
5. Replace the cover and tighten the latches, screws, or wing nut until
snug. The air filter gasket must fit correctly and seal properly. A light
coat of grease on the air cleaner gasket of an older car can improve the
seal between the air cleaner housing and the air filter element.
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