bitterfitter

I have an 06 sierra 4x4, 5.3 auto, bought it new and now has 148K. It has been eating oil since new and has a bad knock on cold starts. Tell ya the truth; it sounds like it is knocking all the time. Just not as bad when it warms up. I drive it daily to work. I want to fix this engine before it blows. I was thinking small cam upgrade, shorty direct fit headers, and whatever is needed to solve this oil and knocking issues. I thought about the cam because I hate to tear into the engine and not upgrade something easy.
Can you guys give me any insight on what cam or headers are better than others? How about what is causing this oil consumption ? I have seen many theories from PCV to poor tooling on the valve stems, but nothing 100% figured out. Did GM stump all of us on this one?

bitterfitter

I am thinking about maybe the LS327 camshaft or I see Scoggin Dickey has a custom ground camshaft called the HT1 for trucks. What do you guys think of these?

CC05

iTrader: (2)

Eating oil since new? Probably should have headed in for some warranty work on that one. Do you know that the truck is knocking or whether or not it's valve "tick", because that tends to happen on cold start-up. Search up on the cam question, because there are a million threads with suggestions for n/a setups. That, and don't bother with headers unless you plan to get a set of lt's. Where you're located, get a set of stainless longtubes. Search up on them, too. Lots of info available.

bitterfitter

I told the dealer about the oil problem and again they say it is within GM tolerances. I have red about others using a quart every 1500 miles or so also. Definetly a problem but not just my engine. I still have not heard from anyone who has found the cause. The knock is not valve tick. It is really bad at cold starts and even noticable at idle when hot. Engine needs to be redone before she blows.
Most of the cam questions on here are building some more power than I am looking for. I just am looking to improve torque and have a nice running everyday truck. I will keep looking. I thought someone might have done this type of rebuild before.

03 BLACKOUTSSS

iTrader: (3)

its more than likely that you are going to spend quite a bit of $$ trying to fix the "tick". unless is real problem, its more than likely its just the standard lifter knock that ALL LS motors have. Just something that we deal with.

As for the eating oil issue, could be several things, all of which require almost complete teardown. Piston rings are probably the culprit, allowing oil past, and it being burned in the CC.

A cam swap without gaining too much power?? The only cam that I can think of, that will give you a decent bump in all around usable power is this.
Probably need to swap valve springs, not sure if the stockers can support that.

either way, with what your looking at, you might consider picking up a crate 5.3 from Scoggin, camming it, then refurbing yours and selling it to reduce your overall cost.

01silvy

I agree, the knock is probly coming from a lifter.. The tick on a cold start up will be pretty fast and kinda high pitched. If your wanting to go through the hassle of chasing down your oil consumption and doing a cam swap, ect.. It sounds like you just need to rebuild the engine and swap your go fast goodies while your doing the rebuild.. I would be willing to bet the crank and rods could be reused so all you would really need is the bearings, pistons and rings, all the valvetrain needs and gaskets.. That would be your only sure fire way to end the oil consumption and swap your cam stuff all in one go.

bitterfitter

I have plenty of years in building engines and this noise is definetly not the lifters. It sounds like either piston slap or a bad rod bearing. It is knocking when I begin to drive when cold and quiets down after about 30 seconds. It never goes away, just not nearly as bad.
If I go with a cam like above do I have to "tune" the truck? and if so, what is involved in doing this? I thought about just buying a new LS327 but mine is an aluminum block and the LS327 is cast iron. I would rather save the 60 lbs. also I hate to buy another new GM engine and have the "acceptable oil consumption" that I have with this one!!!
I figured if I rebuild mine, I can find the oil issue and replace the bearings and cam and be back in action sooner. Hopefully use the same pistons and just replace the rings. Mine should have the Grafal coated pistons from the factory. It was what they called the 5.3 H.O. which had the aluminum block and better pistons.
HAS ANYONE FOUND WHAT IS CAUSING THIS OIL USAGE IN THESE MOTORS???

bitterfitter

I also new some quick info. I have a chance to buy a replacement crate engine from a friend at a great price. It has a part # of 12620054. I am told it will only fit a 2007-2010. Mine being a 2006 I need to know what the difference's are? Being this is a complete engine with intake, coils, everything I wonder if it is the same engine just a difference in the intake or something I can use from my engine. If it helps, the replacement that will fit mine is part # 89018155. I just need to know the differences in these two. Dealer is not alot of help, I tried.

03 BLACKOUTSSS

iTrader: (3)

that engine should work just fine. physically, it'll go in without any problems. there might be some small electrical stuff to change, like sensor location and wire harness compatibility, but thats small stuff. If its a steal, then grab it up and make it work.

TXSZ66AVLANCHE

iTrader: (7)

07-1- engine will not be a direct swap, reluctor wheel difference will need to be addressed as well as a few other things.