my truck has the famous tapping sound and it has gotten worse, possibly only more noticeable since the headers. got the stethoscope out and listened around, pretty sure its cyl 8. not very loud from the valve cover, very noticeable listening at the primary, loud underneath the truck. read quite a few other threads about it, saw the videos and it is an identical sound to the majority. the engine is at 110K miles and now has me thinking about replacing it since a cam, lifters, oil pump, timing chain, pushrods, gaskets, etc cost about as much as a 6.0 long block and i'll still have 110K on the bottom end. but what the hell is the deal, why is it so common??? my LT1 at 120K has never made racket like this, seems many of these motors do. i've been good about maintenance since i bought it at 42K, good synthetic oils and high quality filters. other than making my truck sound like a turd can any real damage happen from a lifter(s) losing prime? hot oil pressure is 25psi idle and 40psi @ 2K, pretty normal? the noise seems to be the worst after its hot, barely noticeable cold. since the factory lifters are crap what are better options, LS7's? but they're factory as well. i'm buying $2k worth of trans this week, now possibly an engine on a 6yr old truck. kinda ridiculous.

 

The Ls has a more agressive rocker arm ratio, 1.7 vs a LT1 @ 1.5:1. That combined with poor lifter body to plunger tolerance, and or lifter to bore clerence is what causes the issue. Add a more agressive cam, plus more spring and it will get really bad. Some engines are quieter than others, and this is why...

 

25psi @ idle seems low. mine runs 40psi @ idle when hot... around 55 to 60 psi when cold...

 

What oil you runnin in that thing??Granted the gauges in these trucks are not 100% but the lowest i see on the gauge in the tahoe is 35-40 when hot...Thats 5/30 winter and 10/30 in warmer temps...

 

25 psi at idle indicates some kind of problem in the bottom end.

 

It's low but within specs if it hits 60 at WOT. My old one was about that low until the bypass got stuck and I had to replace it. I just put new lifters in my 2003 6.0 and the old ones were actually the newer LS7 style. I can't believe how much quieter mine is now.

 

i'll have to see what mine is at WOT. you already had the LS7 style lifters? meaning you're on at least your third set?!? that's comforting.

 

cam/lifters/springs/oil pump/timing chain/pushrods/gaskets will cost WAY MORE than a 6.0L... you can usually get them for 1000-1500 some have even found them cheaper....

i went 13.60 with a stock 6.0 with headers, a 3000 stall and 4.10 gears on a 4.8 stock tune in a EXT CAB.... so in a single cab... you should fly...

 

didn't these motor have a problem with the oring at the pickup tube?

I have seen two that had lifter rattle and it was the oring on the pickup tube causeing low idle oil pressure rattle.

 

That's an installation error, not an inherent design flaw.