when to replace fuel filter?

[peter]

Is there a non-oem fuel filter that would work in a 2002 impreza wrx? I like
to use a see-thru filter so I know when it is dirty enough to replace.
Otherwise, how do you know when to replace it? Guess?

https://www.subarugenuineparts.com/product_info.php?products_id=1114

 

[mulder]

Is there a non-oem fuel filter that would work in a 2002 impreza wrx? I like
to use a see-thru filter so I know when it is dirty enough to replace.
Otherwise, how do you know when to replace it? Guess?

https://www.subarugenuineparts.com/product_info.php?products_id=1114

There are no see-throughs since the filter has to be metal, but you
can get an aftermarket one at the part store. Purolator makes one,
NAPA probably has them as well. The filter is normally replaced at the
30K service interval, you can see the maintenance schedule on the
Subaru website or in your owners manual package.

 

[Edward Hayes]

I believe that all external Subaru fuel filters now have a change
interval at 60,000 miles. Originally the change interval was 30K but,
that was upgraded to 60K ~2004? The fuel filter on my Forester S is
about as large as a small oil filter and probably never needs to be
changed unless you get a load of water.

 

[CompUser]

Is there a non-oem fuel filter that would work in a 2002 impreza wrx? I like
to use a see-thru filter so I know when it is dirty enough to replace.
Otherwise, how do you know when to replace it? Guess?

https://www.subarugenuineparts.com/product_info.php?products_id=1114

Advance has a filter for about $15 bucks...30-45K
is probably worthwhile, without going overboard.

 

[DK]

OK, now someone please clue me in WRT fuel filters. Maybe I
misunderstand something:

Why would anyone want/need to change fuel filter if there are no
real life indications to do so?

Inline filters under positive pressure don't break, they get clogged.
And when the filter is clogged, the performance suffers but the
dirt and crap still does not get into the engine. So, why is googling
brings all kind of "changing fuel filter every 15Kmi is one of the best
maintenance things you can do"?

And why did Subaru changed fuel filter replacement schedule from
30 to 60 Kmi even though it seems that exactly the same filter is
used?

DK

 

[y_p_w]

OK, now someone please clue me in WRT fuel filters. Maybe I
misunderstand something:

Why would anyone want/need to change fuel filter if there are no
real life indications to do so?

Theoretically no filters are"perfect traps" for all solid particles.
Previously trapped particles are constantly being forced through
by pressure. A really clogged filter may even start coughing up
lots of contaminants, but I'd think the rate at which the particles
are released would go up with use. Most recomendations used
to be for oil filters to be replaced with every other oil change.

There are some pretty nasty things in gasoline. Take a look at
the filler nozzle and see how much metal has been scraped off.
One theory is that these metal shavings can puncture through
filter material and the longer the filter is in service, the greater
the chance that it gets compromised.

Inline filters under positive pressure don't break, they get clogged.
And when the filter is clogged, the performance suffers but the
dirt and crap still does not get into the engine. So, why is googling
brings all kind of "changing fuel filter every 15Kmi is one of the best
maintenance things you can do"?

And why did Subaru changed fuel filter replacement schedule from
30 to 60 Kmi even though it seems that exactly the same filter is
used?

Don't know. The recommendations for fuel filter replacement for
the WRX was always 60K miles. I remember stuff like a Honda
modification of its timing belt change interval from 60K to 90K
miles. 30K miles sounds really conservative. In fact I think
Subaru's 30K interval for coolant changes is fairly conservative.
They use a long-life coolant similar to the ones other Japanese
carmakers are using, but without the extended replacment
recommendation.

 

[Edward Hayes]

I think the 30K interval was overly conservative until they had some
real world experience & feed back. I think the filter is a 100,000
mile filter considering the size of it. Of course if you get a load of
junk or water in the fuel then your done whatever the size.

 

[Greg in IN]

(snip)

Inline filters under positive pressure don't break, they get clogged.
And when the filter is clogged, the performance suffers but the
dirt and crap still does not get into the engine. So, why is googling
brings all kind of "changing fuel filter every 15Kmi is one of the best
maintenance things you can do"?

As the filter traps particulates over time, resistance to fuel flow
increases. Excess resistance will shorten fuel pump life. Visual
inspection is not conclusive. If you want to 'test' the filter.... try
blowing through it and noting the resistance and how it changes over time.

HTH

Greg in IN

 

[Blair Baucom]

The 2004 Forester has a filter under the hood by the washer tank and left
shock tower according to the shop manual. It is scheduled for 30,000 mile
service.

My 2005 Forester still has fuel lines there, but no filter. The Subaru shop
that just did my 30,000 mile service says there is only the filter in the
tank that gets replaced at 60,000 miles.

You can see this change on the maintenance schedules from 2004 to 2005.

Blair

 

[Rick Courtright]

Hi,

Why would anyone want/need to change fuel filter if there are no
real life indications to do so?

One overly simplistic answer: so you DON'T end up with any real life
indications!

I had one really strange experience recently that helps illustrate an
extreme of this. I bought an '88 Toyota pickup from a lady whose late
husband bought it new. In almost 18 yrs, it had gone all of 63k miles,
and, according to his log book in the glove box, the last fuel purchase
was nearly 90 days before his passing, the one prior to that nearly six
months earlier! She had some, but not all of the service records. I did
a quick "visual" on the "see thru" fuel filter, and it looked ok, before
I took the truck on a run of about 500 miles one weekend. On the way
home, it started coughing, sputtering, and I ended up limping it home
the last 30 miles or so at around 20 mph.

Got it home, and diagnosed the problem as almost no fuel flow, so the
first thing I did was replace the filter. Problem solved, but out of
curiosity, I cut open the "clean looking" filter to see why it had
failed. The paper was completely "varnished" over from old fuel sitting
in there... even though it looked "perfect" from the outside!

Inline filters under positive pressure don't break, they get clogged.
And when the filter is clogged, the performance suffers but the
dirt and crap still does not get into the engine.

Uh, not necessarily. As with any other filter, there's a "workable" size
of crud the filter can catch. Below that size, "stuff" will get thru,
and as the filter becomes a bit more clogged, it may or may not allow
more stuff thru (depends upon the design of the system.) I couldn't
believe the size of the stuff I pulled out the injectors of a car whose
fuel pump started to grind itself up once: the filter couldn't keep up
and the injectors and fuel distributor all suffered damage.

I know not everyone agrees, but fuel filters rate up there in the "cheap
insurance" category IMO.

Rick