# Piston slap in 2001 Subaru Forester **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** subaru, forester\ **Created:** [November 22, 2009, 10:03pm UTC](https://community.cartalk.com/t/piston-slap-in-2001-subaru-forester/39871 "2009-11-22T22:03:24Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Katie\_in\_Ossining](https://avatars.discourse-cdn.com/v4/letter/k/fbc32d/32.png) [@Katie\_in\_Ossining](https://community.cartalk.com/u/Katie_in_Ossining)\ **Post date:** [November 22, 2009, 10:03pm UTC](https://community.cartalk.com/t/piston-slap-in-2001-subaru-forester/39871/1 "2009-11-22T22:03:24Z")
My 01 Subaru Forester S has started sounded like a bag of bolts when I start it, especially on cold mornings. The dealer said this is just because its’ old (105,000 miles) and is not really a problem. sounds awful, though,. Is this really something to ignore without consequences? ---
**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\ **Post date:** [November 22, 2009, 10:44pm UTC](https://community.cartalk.com/t/piston-slap-in-2001-subaru-forester/39871/2 "2009-11-22T22:44:50Z")
Some engines, including some Subaru engines of that era, are prone to piston slap when cold. The consensus seems to be that it does no real harm. And, at 105k, it should not be as much of a concern as the timing belt. Has the timing belt been changed? If not, please do it now, along with the water pump, serpentine belt, and all belt tensioners. ---
**Author:** ![Katie\_in\_Ossining](https://avatars.discourse-cdn.com/v4/letter/k/fbc32d/32.png) [@Katie\_in\_Ossining](https://community.cartalk.com/u/Katie_in_Ossining)\ **Post date:** [November 22, 2009, 10:58pm UTC](https://community.cartalk.com/t/piston-slap-in-2001-subaru-forester/39871/3 "2009-11-22T22:58:41Z")
Thanks. Haven’t changed the timing belt yet but will, thanks to your comment. ---
**Author:** ![ok4450](https://avatars.discourse-cdn.com/v4/letter/o/e9bcb4/32.png) [@ok4450](https://community.cartalk.com/u/ok4450)\ **Post date:** [November 22, 2009, 11:12pm UTC](https://community.cartalk.com/t/piston-slap-in-2001-subaru-forester/39871/4 "2009-11-22T23:12:27Z")
You did not define exactly what this noise sounds like but if it’s rhythmnic in nature then it’s not likely piston slap at all. ---
**Author:** ![grampabear2](https://avatars.discourse-cdn.com/v4/letter/g/9de053/32.png) [@grampabear2](https://community.cartalk.com/u/grampabear2)\ **Post date:** [January 12, 2010, 6:07pm UTC](https://community.cartalk.com/t/piston-slap-in-2001-subaru-forester/39871/5 "2010-01-12T18:07:19Z")
I had this problem last year with my 01 forester S.I stay away from my dealer.My local mechanic found the problem right away—a faulty timing belt tensioner.Had him replace it and belt also as it was at 53000 miles.All is well now. He has done all maint.& repairs since I bought it new. ---
**Author:** ![Slipstick](https://avatars.discourse-cdn.com/v4/letter/s/50afbb/32.png) [@Slipstick](https://community.cartalk.com/u/Slipstick)\ **Post date:** [January 16, 2010, 1:53am UTC](https://community.cartalk.com/t/piston-slap-in-2001-subaru-forester/39871/6 "2010-01-16T01:53:18Z")
Any chance it’s valve clatter? I had that problem, same vintage 2001 Forester, around the same mileage, in cold weather only. A treatment with “one of the many fine additives” was a big help. (Gunk “Valve Medic”). ---
**Author:** ![Katie\_in\_Ossining](https://avatars.discourse-cdn.com/v4/letter/k/fbc32d/32.png) [@Katie\_in\_Ossining](https://community.cartalk.com/u/Katie_in_Ossining)\ **Post date:** [January 24, 2010, 2:18am UTC](https://community.cartalk.com/t/piston-slap-in-2001-subaru-forester/39871/7 "2010-01-24T02:18:29Z")
That’s a possibility. A fine additive sounds good. ---
**Author:** ![ok4450](https://avatars.discourse-cdn.com/v4/letter/o/e9bcb4/32.png) [@ok4450](https://community.cartalk.com/u/ok4450)\ **Post date:** [January 24, 2010, 3:20am UTC](https://community.cartalk.com/t/piston-slap-in-2001-subaru-forester/39871/8 "2010-01-24T03:20:11Z")
An additive will not accomplish anything on a mechanical lifter engine.