Rebuilding the 2007 250K mile 5.3- which engine sensors would you replace? Any other tips?

nitro498

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Rebuilding the 5.3 in an 07 Tahoe. I bought Sac City main gasket install spacers (do I need to buy the oil pan gasket jig also) Bought a Sac City Barbell, New BTR cam, lifters, and Beehives (deleting AFM with new tune from a local).

Which sensors get replaced- regardless of age?

Do you use anti-seize on any engine bolts?

Do people still use gorilla snot on all engine gaskets?

Any special techniques when putting together the engine?

Reusing main cap side-bolts requires sealant- do any other bolts get sealant?
 

Geotrash

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Rebuilding the 5.3 in an 07 Tahoe. I bought Sac City main gasket install spacers (do I need to buy the oil pan gasket jig also) Bought a Sac City Barbell, New BTR cam, lifters, and Beehives (deleting AFM with new tune from a local).

Which sensors get replaced- regardless of age?

Do you use anti-seize on any engine bolts?

Do people still use gorilla snot on all engine gaskets?

Any special techniques when putting together the engine?

Reusing main cap side-bolts requires sealant- do any other bolts get sealant?
Gasket install spacers? For the cylinder heads? Did you have them shaved down significantly?

Sensors: knock sensors are cheap and worth replacing, IMHO. Definitely replace the oil pressure sending unit and screen. Coolant temp sensor should be fine and is easy to get to if you ever need a new one later. Oxygen sensors are worth replacing too, while you're in there. - at least the ones upstream of the cats.

I only use anti-sieze on the exhaust manifold bolts on an LS engine. I recommend ARP cylinder head bolts though because they're easier to torque and reusable, but you have to use their lube at installation to get the torque value right. I use blue locktite on the cam plate screws and use ARP bolts with their special lube on the cam sprocket bolts (assuming it's a 3-bolt cam).

The only place where permatex is needed (or recommended) on these engines is on the corners of the oil pan gasket where it meets the front and rear engine cover plates. Use the black variety, sparingly.

Techniques: follow the manuals to the letter. I use the manuals from alldatadiy.com and cross-check with a Haynes manual.

No other bolts get sealant that I can recall.
 

donjetman

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Rebuilding the 5.3 in an 07 Tahoe. I bought Sac City main gasket install spacers (do I need to buy the oil pan gasket jig also) Bought a Sac City Barbell, New BTR cam, lifters, and Beehives (deleting AFM with new tune from a local).

Which sensors get replaced- regardless of age?

Do you use anti-seize on any engine bolts?

Do people still use gorilla snot on all engine gaskets?

Any special techniques when putting together the engine?

Reusing main cap side-bolts requires sealant- do any other bolts get sealant?
Buy a book or something. :) There is a lot to building an engine.
 

iamdub

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Rebuilding the 5.3 in an 07 Tahoe. I bought Sac City main gasket install spacers (do I need to buy the oil pan gasket jig also) Bought a Sac City Barbell, New BTR cam, lifters, and Beehives (deleting AFM with new tune from a local).

Which sensors get replaced- regardless of age?

Do you use anti-seize on any engine bolts?

Do people still use gorilla snot on all engine gaskets?

Any special techniques when putting together the engine?

Reusing main cap side-bolts requires sealant- do any other bolts get sealant?

You mean the front crank seal alignment tool to position the front cover? Good call. I'm cheap, so I use a stock crank pulley to center mine. With the pully in place (not fully torqued) to act as a pivoting center, I measure and adjust each side of the front cover until they are even and within spec (aiming for center of the tolerances). There are specs to hit and, even though it might require a few tries, I prefer to measure and adjust because I like hard numbers. I use a stainless metric ruler as both a flexible straightedge and a ruler. The jigs just make it a one-and-done deal, but they're expensive. IMO, unless you will be building multiple LS engines, just get a nice ruler and straightedge.

I do the same for the rear cover- I let the seal center the cover on the crank and I verify positioning by measuring before, during and after tightening the bolts. With both covers aligned and torqued, I install the oil pan last and ensure that the rear mating surface is flush with the block once it's torqued. If a cover is too low or high, it'll cause that seal to wear out of round and leak. It could also keep the oil pan from seating properly. If the oil pan is too far forward or back, it could crack when you torque the bell housing bolts. All three covers tie together and are part of the engine's structural support.

IMO, at that mileage, I'd replace the oil pressure sensor, crank and cam sensors and both upstream oxygen sensors. The oil pressure sensor would be replaced just because it's a pain to reach with the engine installed. The crank sensor is a pain as well, but it and the cam sensor should be replaced to ensure accurate engine timing for the tune. The upstream O2 sensors should be fresh for the tune as well. All other sensors are really easy to access and won't affect the tuning. Be sure to clean (or replace if you wanna splurge) the MAF before the tune.

I use anti-seize on the spark plugs and exhaust manifold bolts only. I use an excessive amount of blue Loctite on the flexplate-to-crank bolts, mainly to act as a sealant.

Other than the head gasket and exhaust manifold gaskets, the LS has O-ring style gaskets that should not have any extra sealants, etc. applied to them.

Special techniques- Just adhere to the factory specs, only deviating as necessary for modifications (non-factory hardware, shaved heads, cam, thinner head gaskets, etc.). Speaking of hardware, I'm also too cheap to buy a torque angle gauge. For the TTY bolts, I use a protractor to put dots on the heads around the bolt holes indicating the spec'ed degrees (HERE). I do the same for the crank pulley (HERE). I "glue" the rear main seal into the rear cover with RTV. I plugged the AFM towers (HERE) and the AFM pressure relief circuit (HERE).

It's late and I might not be thinking of something, but, other than the flexplate-to-crank bolts getting Loctite, I don't think there are any other bolts that should have sealant.
 

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