Forester: valve chatter

[P T]

I have a 2004 Forester 2.5X, auto tranny, ~14,000 miles; I've had it for
about 14 months since it was new, and I do not drive it hard.

It has a troubling noise: I can hear valve chatter, or tappet noise, or
pinging, under moderate acceleration. At least, that's what I think it
is. I can hear it more easily with the windows open. It's not terribly
loud; in fact it's almost masked by the overall noise of the vehicle.

Do other people experience this?

 

[Edward Hayes]

My 2000 For4ester with 96,000 miles has done this since new. I can
hear a light pinging under light acceleration.If I open the windows
and especially if I drive by a concrete retaing wall it becomes more
noticable. The engine control module is advancing the ignition timing
to achieve the maximum efficiency. If mine quits doing it I will know
something is wrong. Quit normal. ed

 

[Alan Ronemus]

Subaru switched to solid lifters in their latest engines, so valve adjustment is
necessary periodically. The procedure is covered in the service manual. On my
'02 Legacy there is barely enough clearance between the heads and the inner
fender to pull the cam covers and make the adjustment. I did mine after ~3,000
miles and they're still good at ~33,000. The clearance wasn't outside the
service spec, but setting them properly eliminated the noise.

 

[Edward Hayes]

Interesting: My 96,000 mile 2000 Forester with mechanical lifter
exhibits only has a faint tap tap tap from the vales when idling. The
valve adjustment service is listed at 105,000 miles