Found a 2005 Envoy with 5.3 Aluminum Block L.S. Some questions please.

[c good]

Guy close by selling a 2005 Envoy. Denali edition. It has the 5.3 Aluminum LS engine. It has the true 4x4 system with 2 wd, A4WD, 4 High and 4 Low transfer case. GT4 and G80 differential. It also has the Active Fuel Management system. 126 K miles.

It has the L460 E transmission that is currently having trouble locking up in 4th. So will need some transmission work.

I like the shorter wheelbase and overall lenght of the standard Envoy as it's more manuverable for my light offroading. But I don't like that I can barely sleep in it and can't stretch out.

My questions are.

1. Is the aluminum LS engine a good engine or should I stick with a cast iron version in a different vehicle?
2. I've read bad things about the AFM system.....is that something to avoid if it's working correctly?
3. I'm assuming it does not have a tow/haul option or did they make the Denali version with Tow/Haul?
4. Should I just look for a Tahoe and live with the little extra lenght, a Tow/Haul feature, and no AFM?

5. It appears to be in great shape. No accidents, average wear and tear. What would be a good price for it given that the transmission may have to be rebuilt?

Thank you as always for your input. Cam

 

[TollKeeper]

No GMT360 came from the factory with a Tow/Haul mode.

The 2005 AFM/DOD engine is a good engine, as long as the AFM/DOD is turned off/tuned out. The 2 things that are bad about the 2005 v8 is the AFM/DOD, and that it is a 2005-2006 engine ONLY. 2005-2006 are 24x engines with the AFM/DOD. 2004 and older are 24x only. 2007 and up are 58x with AFM/DOD.

My Aluminum 2004 5.3 Envoy is high miles, and runs perfect.

If you were going with a boosted application, than I would say find a Iron Block. But for what you are doing, the aluminum block is great.

As for the 4L60E trans on it... Thats the big downfall for most of the 2000-2010 model year GM.. They are a OK transmission.. But dont take well to abuse or neglect.

 

[c good]

Thanks for the info Tollkeeper. What is a 24x engine? What is a 58x engine?

 

[RedEnvoyDenali]

And how do you tell which one you have? I have an 06 with 300Km and it is still running quite good. A little noisy on start up but still runs fine and uses the appropriate amount of oil. I have a small oil pan leak that haven't fixed due to the high cost to replace a 40.00 gasket.

 

[TollKeeper]

Thanks for the info Tollkeeper. What is a 24x engine? What is a 58x engine?

A 24x and a 58x engine is how the computer interprets the timing signal provided by the timing cog on the crankshaft. A 24x engine has... well 24 timing notch's. A 58x engine has... 58 timing notch's.

And how do you tell which one you have? I have an 06 with 300Km and it is still running quite good. A little noisy on start up but still runs fine and uses the appropriate amount of oil. I have a small oil pan leak that haven't fixed due to the high cost to replace a 40.00 gasket.

You actually answered your own question. You have a 2006, you have a 24x engine. Doesnt matter if you have a 4.8 LR4 8th digit VIN V, a 5.3 LH6 8th digit of the VIN M, or a 6.0 LS2 8th digit of the VIN H. They are all 24x as long as its a 2005 or 2006.

I will say that GM was stupid in regards to the LH6 5.3. They used the same VIN designation for the 24x in the 2005-2006, and the 58x in the 5.3 for the 2007-2009... and for the 6.0 found in the TBSS VIN code H LS2.

So you just have to watch the model year the engine is coming out of. 2005-2006 for the GMT360 will only work in the 2005-2006 24x ECM. And the 2007-2009 for the GMT360 will only work with the 58X ECM.

I have heard that you can use the 2002-2004 LM4 5.3 VIN P in the 2005-2006 GMT360.... As long as you turn off the AFM/DOD in the ECM. I still dont quite understand how the knock sensor works thou, as they are in completely different locations.

 

[c good]

Is there a performance advantage with the more timing points of the 58x?

 

[TollKeeper]

Not sure on that one.

 

[Brnstrmr]

how does the knock sensor play into it, please?

 

[TollKeeper]

On the 2002-2004 the knock sensor is in the intake valley. There are 2 of them.

On the 2005+, the knock sensors were moved to the side of the block, and the intake valley pan was now needed for the VLOM for the AFM/DOD system.

The 2 black plugs on the intake valley are the Knock sensors.

This is a 2005+ Intake Valley Pan, AKA a VLOM

 

[RedEnvoyDenali]

Many thanks for the reply regarding the 24x. One more question. I really like my 06 Envoy Denali and would consider repowering if that becomes necessary. Would i need to be concerned if i ordered am M code 5.3. I seem to think it would have to be a 24x or is there some work around to the 58x through the computer?

 

[azswiss]

Lingenfelter sells a converter box that allows you to use a 58x Gen IV engine in a 24x application.
But . . . in addition to the converter box you will need to swap out the knock sensors, resize/drill/tap the knock sensor mounting hole in the Gen IV block, and connect the cam & knock sensors thru an adapter cable into the existing harness/ECU setup.

This video provides a concise overview: SDPC Tech Tips: Gen 3 and Gen 4 LS Engine

Edit: AFM/DOD delete likely required/recommended.

 

[RedEnvoyDenali]

many thanks for the info which was very informative.