1996 sierra tick tick ticking
My truck is a 1996 sierra SLE 4.3L that has a ticking sound coming from the engine . When the truck is started cold it makes no noise at all , when the engine starts to warm up it starts to tick getting progressively louder . So far i have tried to flush the engine using four quarts of oil to 1 quart of atf4 and driving it 30 to 50 miles . I have also used seafoam in the gas tank, brake booster , and oil. Today i pulled off both valve covers to inspect all the push-rods ,rocker arms ,bolts , I also replaced the donut gasket and intake gaskets in the passenger side. I did notice i had a bunch of loose rocker arms , however the sound is still there after they are all tightened down . Finally i sprayed b12 chemtool into each of the push-rods to clean the lifters from both sides if they are stuck . Non of this has fixed the problem , what else could be causing this ?
96 sierra SLE 4.3L vortec v6
Sound is heard best under the truck on is passenger wheel well .
Sound only starts when the engine is warm.
The sound does not get worse when depressing the gas pedal in fact it vanishes higher rpm .
Oil pressure is between 40 and 50 something .