2005 OB. Original engine pulled*; installed an EJ251 (no history) with the proper parts from the '05 - Cam and Crank sprockets and IM, etc. 

 

Got this noise on the Driver's side: https://youtube.com/shorts/_SV_YqaVGrs?si=RR28wJ05PoxhatR5

and from underneath: https://youtu.be/Kv8IuDBbvFw

 

 

- I set the valve clearance (on all the valves), which made no difference.

 - Pulled the injector's wiring on both Driver's side fuel injectors - no difference.

Other info. 

- Drive's OK - power seems normal - for a 2.5. 

- Get a CEL for P0420 after 2 drive cycles, which I've not diagnosed. Using this for reference: https://www.subaruoutback.org/threads/p0420-diagnosis.49537/

 

I had a similar noise in a '96 Legacy that turned out to be a stuck piston ring. https://www.ultimatesubaru.org/forum/topic/154755-swapped-out-the-hlas-for-slasstill-got-the-tick/

 

 

 

Is that Rod Knock? Wrist Pin? Stuck Ring(s)? Etc.
 

Thanks for the feedback. 

 

 

* Original EJ253's tensioner bolt broke and caused valve/piston damage.

Edited September 17, 20232 yr by wtdash

does the noise get increasingly aggressive-sounding with increased rpm, or, does it kinda come-and-go ?

 

if the latter, might be a weak tensioner.

 

 

Edited September 17, 20232 yr by 1 Lucky Texan

^Thanks for the reply.

 

It's RPM dependent - cold and warm - it changes w/the idle speed - and isn't any worse sounding when revved - even to 6K.  And is concentrated over Cylinder 4 area. 

Above (in my post) is cold start. Here is the warmed-up: 

 

 

 

Edited September 22, 20232 yr by wtdash