knock, knock

[Sandy Hawes]

New to this list, and new to Subarus in general, but I've got a question and
I'm sure you lads can help....

My '04 Forrester (73k kms) has begun to knock. It became slightly noticible
afer my* first or 2nd oil change *(I bought it at 53k kms) and has been
growing increasingly louder. Outside temps have been getting increasingly
colder at the same time, but nothing lower than -10C. It gets better as it
warms up but does not go away completely. It is very similar sounding to
the knocking "oval piston" problem that Ford had. Power is good, no blue
puffs, mileage is ok (it has been dropping with temp, naturally). I tend to
baby this rig and rarely let it see anything beyond 4k rpm and never above
4.5k rpm. Oil is changed every 5k kms (more than recommended by Subaru).

Here's the deal - If it were my old V6 Ford I'd say it was maybe a sticky
lifter - but this is a "boxer" and I just don't have any experience with
them. I'd like to not appear too stupid when I approach the dealer with
this issue so any and all help would be appreciated. The noise is just
audible inside under harder acceleration. Has anyone had a similar
experience, have any info, educated guesses, or links to sites with
information?

I better stop typing so you guys can answer....! Thanks in advance.

 

[Fuzzy Logic]

New to this list, and new to Subarus in general, but I've got a question
and I'm sure you lads can help....

My '04 Forrester (73k kms) has begun to knock. It became slightly
noticible afer my* first or 2nd oil change *(I bought it at 53k kms) and
has been growing increasingly louder. Outside temps have been getting
increasingly colder at the same time, but nothing lower than -10C. It
gets better as it warms up but does not go away completely. It is very
similar sounding to the knocking "oval piston" problem that Ford had.
Power is good, no blue puffs, mileage is ok (it has been dropping with
temp, naturally). I tend to baby this rig and rarely let it see
anything beyond 4k rpm and never above 4.5k rpm. Oil is changed every
5k kms (more than recommended by Subaru).

Here's the deal - If it were my old V6 Ford I'd say it was maybe a
sticky lifter - but this is a "boxer" and I just don't have any
experience with them. I'd like to not appear too stupid when I approach
the dealer with this issue so any and all help would be appreciated.
The noise is just audible inside under harder acceleration. Has anyone
had a similar experience, have any info, educated guesses, or links to
sites with information?

I better stop typing so you guys can answer....! Thanks in advance.

My '03 Impreza developed a very loud knock at cold temperatures and the
knock pretty much went away when the vehicle had warmed up. Turned out to be
the belt tensioner and was replaced under warranty.

 

[Todd H.]

My '03 Impreza developed a very loud knock at cold temperatures and the
knock pretty much went away when the vehicle had warmed up. Turned out to be
the belt tensioner and was replaced under warranty.

My 01 Outback had that same problem and remedy 5 or 6 times.

It never really goes away in total.

 

[P T]

Hmm, now that you mention it, when I start out in the morning now with
the cold engine (Minnesota) I hear a knock too in my 3 year old
Forrester. I guess I mostly have been ignoring it, as it gets better as
it warms up (I think.) Maybe I should do something about it. I suppose
our warranty is only 3 years, huh? Too late.

Is this something I really need to attend to, or can I just turn up the
radio?

 

[Blair Baucom]

My 2005 Forester is making a noise at 4,000 to 4,500 rpm, but I think it is
the infamous exhaust heat shield noise. I have 47,000 miles so far.

Blair

 

[Blair Baucom]

Should be covered by the power train warranty.5 years or 60,000 miles.

Blair

 

[StephenW]

Some subies have piston slap, a knock like sound that has no cure (according
to the subaru gods). Not sure what engines it covers. couldent find anything
on yours, but found this:

02-93-04 tsb covers a knocking noise due to timing belt tensioner bracket
(Vin's and porduction dates apply)



--
Steve
ASE Master Tech
L1 Diag
Currently residing at a Subaru Shop
4.5 years doing tires and alighnments

 

[Sandy Hawes]

Thanks Steve. Good info. I'm hoping its the tensioner.