Hi:

I just purchased a 2002 outback with only 17,500 miles and I am a little suprised that the engine is still noisy. There is a moderate knocking sound under light acceleration around 2500-2700 RPM only. Wide open it's fine. Idle is fine. Noise is same whether engine is cold or hot, so I don't suspect piston slap. I have only 2 days left on the 3yr/36K waranty (though I think the engine is covered under 5yr/60k) and I am wondering if I should take it to the dealer or if this is normal. My old 98 DOHC 2.5 phase 1 was noisy too, but I was hoping this was eliminated in this newer SOHC 2.5 phase 2 engine. Thanks for any info.

Rich

rjpoutlook,

 

My 97 OBW had a very noisy piston slap when cold and my 02 OBW has the same noise, but much less so. As you most likely have found out, it is more of an annoyance than a detriment to the engine's longevity. Why Subaru hasn't fixed this over the years is puzzling, since I'm certain it has cost them customers. In my case, the cars do so many other things so well, that I overlook the less than sophisticated sound coming from the engine compartment. Only you can decide if the piston slap is annoying enough to turn the vehicle back in.

rjpoutlook,

 

My 97 OBW had a very noisy piston slap when cold and my 02 OBW has the same noise, but much less so. As you most likely have found out, it is more of an annoyance than a detriment to the engine's longevity. Why Subaru hasn't fixed this over the years is puzzling, since I'm certain it has cost them customers. In my case, the cars do so many other things so well, that I overlook the less than sophisticated sound coming from the engine compartment. Only you can decide if the piston slap is annoying enough to turn the vehicle back in.

I'm not sure this noise is piston slap. For one thing, it does not diminish at all when the engine heats up. It is always just the same, and only under light acceleration.

what kind of valve train do these things have? if the valves are susceptilbe to being noisey maybe an oil change or change in oil weight would help. the older soobs had hydraulic valve adjusters in them which were prone to be very noisey, particularly with dirty oil.

 

what exactly is piston slap and why does it happen and why does it go away when warm?

every subie motor ive ever heard makes noises that sound like subie motor noises, my moms 2003 LGT sounds like my old 86' with the same noises, thats just how subies do, i guess.

 

 

 

 

~Josh~