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 .

Have you removed the serpentine belt and started the engine to see if the noise goes away?

Nope, I will give it a try in the morning . Thank you for responding .

I pulled the belt off and the noise is still there . I noticed the rocker arms were lose again , they must have not been tight enough . I'm not sure if this is the problem or not because a stud needs to be replaced and i can not re-torque them without a new stud .

I think there is a heli-coil repair kit for that issue... the studs have pulled out and no longer be tightened because if you tighten them... they are actually just pulling out and not getting tighter

Think it involves tapping the threads for the studs to go into using heli-coil thread in'*

could be a slight leak in the exhaust manifold. typical of when it warms up more check if your bolts are tight and see if you can notice it on one side more than the other. I had that once and it drove me NUTS until I finally figured it out

I thought about that and pulled it off, I did not find any cracks in the manifold . Just to be safe i replaced all the gaskets and even the donut gasket to the mufler . I am at the point you reached where it is driving me crazy. The stud that needs to be replaced is not broken on the bottom but on the top so i will simply replace the bolt.

that might just be it I thought for sure I was getting ready to throw a rod or something. panicked every time I drove the thing then to find something that simple...well I always did learn the hard way. lol

The stud has been replaced , engine re-timed , and all rocker arms set to zero lash plus 1/4 turn . The engine is still tapping it *** off driving me insane, can anyone tell me how to replace the lifters without removing the intake? I read some people do it using a magnet but how?

you take the lifters out by removing rockers, pushrods and pulling them out through the hole. there is a relatively cheap lifter tool that fits in the end and * works better than a magnet