timing belt tensioner bearing

[turbo1600]

ever since i rebuilt the ej25 in my dohc 98 outback , there was this slight rattle for about a second or two ever since first startup ,if i let it sit for say 3 hours or more there would be less rattle/knock for a second , and if i let it sit overnight the knock / rattle would last a fraction longer.engine runs fine no knocking when acclerating or decelerating. i got block rebored, new oil pump , conrods resized, crank reground.

the timing belt seems to be a little slack, maybe...
i done some reasearch and read that the timing belt tensioner can cause this symptom.

i had two engines ( both ej25) one from a liberty 1999 wagon sohc , and the original from my dohc 1998 outback.
i have used the rebuilt sohc block with dohc heads.

and i just happened to notice the two timing belt tensioners are slightly differant , one has a bearing with a i.d of 32 mm , and the other bearing has a i.d of 35 mm. , i cant remember which tensioner setup i used from what engine...

now the two bearing i.ds are differant , does this mean the o.d of bearings is differant as well ?

and measuring from the top of the actual pin from tensioner there is a differance of about 1 mm. see pic .
i have been using the tensioner with the shorter length , and smaller id bearing.

does it matter which tensioner setup i use ?
mk

 

[turbo1600]

found cause of rattling / knocking !

the noise ended up being the hydraulic tensioner. i took of the timing covers, put the ballancer back on, and shoved a small crow bar thingy between the tensioner and the casting an " pumped " the tensioner a few times , started engine up an the noise has completely gone. even after overnite it still doesnt make the noise ! not sure how long it gonna last like that for but i`m putting in a new tensioner in tomorrow..

 

[Kevin]

Good find - thanks for the follow-up