08' Envoy 5.3 as potential donor??

[88Ironduke]

Short story is as such. My daily driver 08' Envoy with the aluminum 5.3 is getting towards the end of daily driver life. Its a good motor and runs solid. I'm considering pulling the engine/transmission to use a donor for my 72' C-10long bed.

A couple of questions for the LS gurus. Can I have a shop convert my 4wd (I assume 4L60E) transmission over to a 2wd output tail shaft (I know the guts have to come out), remove the 4wd wiring and flash the ECM to remove knowledge it had a 4wd gear box? Can anyone say if the exhaust manifolds are the same as the TBSS which seem to fit our trucks rather well?

This won't be my first LS swap but it'll be the first time I've pulled one from its factory home to use. Any information you guys have on this particular donor would be appreciated.

Thanks
Paul

[jrblanke]

I am using a 5.3 from a 2006 trailblazer LT 4x4 . I personally wouldn't use a trailblazer again because I think I would have come out cheaper had I just bought a 2wd truck donor vehicle.

The trans can be converted to a 2wd which is what I did. If you can keep yourself from the "while you are at it" things then you can convert it pretty cheaply. However, I went ahead and bought a rebuild kit, new torque converter, shift kit, boose valve, etc. So I have almost 500 bucks in my transmission in addition to the donor vehicle cost. I'm not finished with my swap yet, so I don't know if there is anything special that has to be done with the computer or harness.

The other things that were a pain were the fact that the front axle goes through the oil pan. So to remove the engine, you have to remove the front axles to get the engine and trans out. You don't have to get another oil pan, but I did because I didn't want that goofy looking hole in the side of the pan. Well, when you change the pan, your AC bracket will not have enough support because at least 2 of the bolts (if memory serves me correctly) that help mount it to the pan. I didn't want to have to buy a new AC compressor, so I made a bracket/spacer to go in between the engine block and the AC compressor.

The power steering pump on my TB didn't work because it hit the A-arm (84 2wd C10). So I have to buy a truck pump and front mounting bracket.

There was a pretty good thread where someone used a TBSS to do their swap into a truck similar to yours. I think his user name was Killers or something like that. I haven't read it in a few years.

That's all I can think of right now.

[88Ironduke]

Thanks for the heads up about the A/C bracket but I have to say the power steering pump inference was a little bit of a surprise. My 72' has round about the placement of A-arm components so that would have to be parts swap. I knew about the oil pan (only GM would send a drive shaft thru the oil pan intentionally) and it was a known factor. I'm going to talk to transmission guy I know and what he would charge for a input shaft swap. Having the entire donor in working order and time to dismantle is super cool. But I have to balance cost versus awesome factor of stealing that aluminum 5.3...

Paul

[71cadc10]

Radiator looks like it can be a good piece to swap...the inlet/outlet are both on pass. side like the aftermarket ones place them. conversion to 2wd is fairly well spelled out I would think on some TBSS forums...the intake and exhaust manifolds you got fit nicely. If the truck is essentially 'free' like you are going to scrap it or donate it, I think I'd use it yes. it's a gen IV engine without DOD I believe..should run forever.
I have a 2006 Saab 9-7 with the 5.3 and it has the DOD but I think 08/09 they stopped using it.

[88Ironduke]

You're right on the DOD... A cam, lifters and push rods. Just a basic engine that's got allot of life left. I'm not a transmission guy so I'll keep my nose out of it. I've taken apart enough things and not have them go back together properly. I'll stay in my lane.

[jrblanke]

Ah, that was the thing I forgot about. I also eliminated the DOD which contributed to the extra cost of using that engine.

[ls1nova71]

I say go for it! You already own it, so you know how well it runs and was maintained. The parts that people say wont fit are dirt cheap at the pick n pull, I mean, you cant really give away a front accessory drive off a 5.3 truck engine now days!! The oil pan you'll want to swap anyway, even if it came from a full size truck. The GM muscle car pan fits pretty well in a truck, and comes with everything you need to convert it for a couple hundred bucks.

[88Ironduke]

Thanks guys. I'm going to be getting my parts list together and start working pooling resources for a summer work session!

Paul

[jrblanke]

I'm looking forward to reading the build!

[71cadc10]

what I was getting at, is your 2008 should not have the DOD on it....you shouldn't have to convert it.
quick look at the valley cover plate can confirm.

[88Ironduke]

Originally Posted by 71cadc10

what I was getting at, is your 2008 should not have the DOD on it....you shouldn't have to convert it.
quick look at the valley cover plate can confirm.

Its a non-DOD engine. I'm pretty stoked but there is something about taking apart a working vehicle that does what its supposed to. But I'll have super sweet leather heated bucket seats when I'm done.

Paul

[ls1nova71]

Whats even better is if your '72 currently runs, because then you get to take apart TWO trucks that run! Lol! Been there, you'll get over it in a hurry!

[71cadc10]

my 2006 Saab is a DOD version...crappiest deal going. bought it at auction with 79K on it...reason it went to auction was for constant misfire.
I turned off the DOD via HP tuners...seafoamed it, and put in new plugs. Still develops a misfire on cyl #1 after 5k or so daily miles but it does run a lot better.
I'm thinking the rings are shot. It's a shame cause I know these things can go 200K+ miles easy if not equipped with the oil coking package LOL
2006 was about the first year the DOD was put on the 5.3 and the programming was not well thought out....GM revised it then about 08/09

[88Ironduke]

Very happy with the 5.3 in Envoy. The only major headaches thus far was a parasitic draw via On-Star module staying awake and fighting with the BCM and changing the A/C compressor last year. If you haven't dealt with that little gem you're lucky. Even with the water pump/fan/fan shroud etc all removed you're still going to lose a socket on the passenger side.

[e015475]

I have the aluminum TB 5.3 in my truck.

I bought the drive by cable throttle body, ECM, harness and all the accessories off a truck at a local junkyard for $75.

Found a truck oil pan on CL for $40 to replace the one with the hole in it.

I don't know how they check the oil in a TB, but mine didn't have a dipstick hole in the block. The cast boss was there, but no hole. I had to drill one

[88Ironduke]

Originally Posted by e015475

I have the aluminum TB 5.3 in my truck.

I bought the drive by cable throttle body, ECM, harness and all the accessories off a truck at a local junkyard for $75.

Found a truck oil pan on CL for $40 to replace the one with the hole in it.

I don't know how they check the oil in a TB, but mine didn't have a dipstick hole in the block. The cast boss was there, but no hole. I had to drill one

Interesting issue on the dip stick. That's one I'm going to figure out... Thanks.

I do like the drive by cable versus DBW scenario. I did a 81' Firebird with a Tahoe 5.3 that went well but the DBW was a bit of a PITA. I tried to route/integrate the harness into the bulkhead connector for a clean install but it was subject to varying resistance values, then I learned just how sensitive the TPS/TAC module values are it would randomly go into low power mode. A continuous uncut TAC harness fixed it but it took a little bit of head scratching with a meter to figure out what was happening. Need to invest in a PICO....

I'm pretty certain that GM does not produce a DBC setup in the Gen4 engines so the DBW will most likely be staying. I am going to have to source a new pedal assembly as mine is the adjustable type.

Paul

[ls1nova71]

The first year of the aluminum TB engines didnt have the dipstick hole drilled, but the later ones do, but are plugged with a little freeze plug looking thing that you can punch out from the inside while the pan is off. The dipstick is located in the oil pan on those engines so thats why they're plugged. As for a DBW pedal, pretty much any Gen4 pedal should work, unlike the older ones where you needed to have a matched pedal.

[e015475]

I've had conversions with both drive by wire and cable and I like the 'tip-in' of the cable better than the wire.

But wow was it easy to do a cruise control with the wire one.

And I think my TB was the first year they made them (04?)