BrokenNinjaLeg

Im brand new to the LS scene. I just purchased a 2006 Envoy Denali for pretty cheap, but im unsure of what engine it has. I plan to rebuild it because it has an inconsistent miss and the slightest amount of non-magnetic metal in the oil. After removing the intake, i can see that it doesn't have a DOD valley cover. It has a gen 4 valley cover with no knock sensors or plug in the back. Im assuming the LH6 was swapped out of this vehicle with another gen 4 engine. The only codes i found were for the oil pressure sensor and for the missfire. It runs, drives and shifts perfectly, aside from the miss, with 168k on the dash. What engine could this be?

G Atsma

It could still be an LH6 that's been converted to non-AFM/DOD. It's not that involved, though head removal is needed to switch out the lifters and trays. It might still have the original cam.
Any way of getting any casting numbers? It might not be a 5.3, though it most likely still is.

BrokenNinjaLeg

G Atsma

That block # does apply to the LH6, but it also was used on all the other Gen IV 5.3 aluminum blocks, the main differences of which were whether or not they had AFM/DOD and/or VVT., and one of 2 different cams. Otherwise, all aluminum Gen IV 5.3's are the same
You likely have an LH6 on which AFM/DOD was deleted. The LH6 didn't have VVT so you don't have that.
I hope this helped!

B52bombardier1

That 168,000 is not a lot for these engines and you might consider holding off on the rebuild. And that misfire might be an easy fix.

Rick

BrokenNinjaLeg

Im aware that 168k isn't much at all for an LS engine. I've seen them go 300k and further myself. My concern was the metal in the oil, not so much the missfire or mileage. I also planned on deleting the DOD system, but that seems to have been at least halfway taken care of for me. Tearing it down further I see that it has a blue felpro head gasket on one side and what looks to be a factory head gasket on the other. It also has a new con rod, and a concerning amount of missing bolts.

Che70velle

iTrader: (6)

From the looks of the rod, and the remaining metal in there, someone did a quick patch and go to it. I’d 100% tear it down and go through it all…but I’m **** about everything and want it all correct, not just “close enough”.

LS1Formulation

iTrader: (13)

When I tore my LH6 down with roughly the same mileage, it was toast. Had .002 taper in the bores, a lot of scoring, and numerous bearings had copper showing. Not only that, but it had the oil bypass issue with the oil pan and wouldn't hold oil pressure at idle. I wasn't planning on using it stock anyway, but it was not in good shape. LS engines that aren't DOD may last 300K, but I highly doubt there are many that came equipped with DOD ( even if it got deleted ) that have made it past 200K. I would tear it completely down and at least clean the block and re-ring it with new bearings.