got a 99 silverado 3500 gots a 5.7 vortec that had 240000 on it and it finally gave up with a rod knockin . so i buy a long block put it in cranked right up ran great but sounded like a lifter rattling wasnt much worried bout it just outa adjustment right. pulled valve covers tried to adjust running, but noise wouldnt go away. so i went with the tdc method setting valves while not running-put valve covers back on still has noise. drove it to place i bought long block and guy says i must of messed up and collapsed a lifter or something (which isnt true cause it was making noise before i even touched lifter) he said either i collapsed a lifter or they werent adjusted right . well i know theyre not adjusted wrong so i went home bought another set of lifters put them in adjusted valves tdc not running method remove lash and then one full turn. cranked it up still makes same noise. so i pulled covers off cranked it up backed adjustment off till ticking then tighten till ticking stops then 1/2 turn i tried going 3/4 but still same result. Anyways i bought a premium long block but think im gonna get the premium long c--k on this deal. when i talked to sales manager he seems dead set on making this my fault even though ive done it all right . what im asking is has anyone had experience like this or any ideas on what noise could be. it sounds like lifters to me the best way i could sum up noise is my truck sounds like a diesel and its not. but it runs great ,oil pressure good,no blow by,good power just that dam noise. any ideas would greatly appreciated

 

Exhaust leak.

Allan

 

the exhaust is good allen i wish that was it . has anyone ever ran a flat lifter cam with roller lifters? would that possibly cause the lifter rattle noise . im not familiar with the difference in the cams but hey if you had a slightly older short block with vortec heads would you have to make sure you had a roller cam with roller lifters just looking at possibilities ?

 

Could it possibly be a loud injector?

 

i dont know it wasnt doing before i ckanged engine out it just had a rod knocking but not this noise that i recall. these cold mornings it really loud when u first start it, after it warms up just sounds like a lifter makes me suspect piston slap but really hard for me to know. will injectors make a noise like i described im really stumped and not sure what direction to go with it . it still runs good good oil pressure good power no blowby but man it almost sounds like a rod till it warms up a little then sounds more like lifter