5cardpimp

Truck is a 2004 Tahoe Loaded AWD 5.3L flexfuel with 140k km's (bout 80k miles) Engine completely stock.

I have a strange noise which i have isolated as internal. Got about 3 opinions on it so far, and the one that makes sense is a lifter is seizing. As everyone else did, i thought it was belt/pulley/pump noise. Did water pump/pulleys, was in to it a couple different times. Removed both belts, removed balancer, and inspected flexplate.

I am now convinced its either a lifter or a cam bearing.

It did suddenly start making the noise one morning, and is consistent with rpm. It sounds like a belt noise like i said, but it seems like its on the passenger side bank and the noise is loudest when i stick my head in the passenger wheel well. Now im swaying farther towards a lifter than a bearing seeing that it seems like its only every 2nd rotation, but i understand that neccesarilly doesnt rule out a bearing.

Now i have been doing some reading, and i am somewhat familiar with the ls1, yet i have not torn in to it myself personally. I am far more experienced with gen I small blocks, and yes i understand they have very few similarities when it comes to design.

Now come the questions:

1. Are these factory lifters different then the "GM perf. pn: 12499225" lifters? Are these lifters a common problem? I was told the flexfuel cams differ slightly.

2. When I tear the heads off, am i able to reuse the head studs? Or do i need replacements? Any other major parts that will be needed? I plan on putting in full set of 16 lifters.

Main parts list:

"12499225" GMperf lifter set.
head gasket set
Intake/exhaust gasket set.

Anything else i should be worried about? is there some sort of kit alternative to buying the gaskets seperately? I am younger (22 y/o) and i dont plan on keeping the vehicle for much longer, yet i dont mind doing this my work has i have the resoursces for it.

O2Form

I'd pull the oil filter off and cut it open, it will tell you alot about what is going on. Squealing is a sure sign a bearing is cooked.

5cardpimp

Squealing was the wrong term. Taking note, i do prefer regular oil changes with penzoil (ya i do the drive through, but only because this truck is too low to use a creeper under, and gravel driveways suck for oil changes).

Its more of a brief squeak, and by no means is it during the full 4 cycles. It definately is either half cycle or quarter cycle continuity, and it is completely constant related to engine speed.

Now the 2 previous owners to me were both older gentlemen, and this truck has been babied. Now i am not abusive, but i do open it up once in a while (honestly, the price of gas+my age/income makes me not afford it lol) and maybe some deposits have recently free'd themselves? I also did get a engine flush when i got my oil changed bout 3 weeks ago, but problem started bout a week after.

Edit: also would i be ok just buying new filter and changing, without changine oil? im probly not going to run it again until i change lifters, and after i will change both oil/filter. I ask this just so i can cut the old one apart, assuming i probly wont be seeing much in the filter unless it has seized fully and is just eating cam?