unsure of tracker noise
 

new to the site, have gathered alot of useful info from here. i have a 91 tracker owned for 3 months. 1.6l supposed to have a new top end??? i am hearing a noise, like a rattle or piston slap toward the back of the engine. it does this only when warm and below 1200 rpm, sounds like a wrist pin or rod??? the only odd thing that has me guessing is that is erratic,,,, it rattles then goes away a few seconds then back, never sounds the same. is there a dis gear or anything else that could be doing this or is common for this engine. i have had the cover off and readjusted all valves and everything seems okay here. its not a valve noise or a injector noise. just checking with you guys that know alot more about this engine than i, and before i pull it out to rebuild. engine shows 150k and i am running 10/40 synthetic, no leaking or oil usage at all. thanks for any info