New air filter causing engine sound change? OBW

[Ryk]

I changed the air filter on my 2000 Outback wagon and it seems to have
caused a change in the in-cab sound of the engine. Now when I give it a lot
of gas I hear a low frequency sound -- not really "throaty", but the kind of
sound I associate with, say, a souped-up Honda or Toyota.

The filter I changed was pretty dirty, so it could just be that it used to
make this sound when clean, but I don't think so. And there are no other
symptoms (mileage is same, no smells, etc.) I double-checked to be sure the
filter is properly installed and tightly sealed.

Does this sound normal? Abnormal?

Thanks!

 

[TM]

I think it would be abnormal. Did you check all the Air intake ducts
that connect to the filter housing?

Good luck!

 

[Charlie]

Make sure that the air filter cover is snap correctly on the casing. I had
the same problem a few years back and the cover was not snap correctly on
the air filter casing.

The best thing is to open it again and make sure that the plastic pegs of
the cover are getting in the openings of the casing.

Keep us informed

Charles
2000 Impreza Wagon

 

[Yousuf Khan]

I changed the air filter on my 2000 Outback wagon and it seems to have
caused a change in the in-cab sound of the engine. Now when I give it a lot
of gas I hear a low frequency sound -- not really "throaty", but the kind of
sound I associate with, say, a souped-up Honda or Toyota.

The filter I changed was pretty dirty, so it could just be that it used to
make this sound when clean, but I don't think so. And there are no other
symptoms (mileage is same, no smells, etc.) I double-checked to be sure the
filter is properly installed and tightly sealed.

Does this sound normal? Abnormal?

I had this same problem about two years ago, when I changed the air filter
in my 2000 OBW. It seems like the service people installed the filter in
wrong and left a small gap down the side of the filter and filter housing
which allowed unfiltered air to go through the engine. It actually resulted
in lower power.

Yousuf Khan

 

[Ryk]

Thanks you all!! Since three people thought my issue was abnormal, I
pursued it. A closer look at the air filter casing showed that I didn't
have a good seal along the bottom. It's pretty hard to see some of it, but
I found that one side of the casing basically attaches to the other by a
hinging motion along the bottom edge. I didn't have that tight and that was
the problem. Reseating it stopped the engine noise and definitelyl boosted
my acceleration.

Thanks again, guys -- I can always count on the smart newsgroup masses!