Replacement motor '06 Envoy Denali

[subssonic]

My motor is seized and I'm trying to figure out my options. The factory used replacement is REALLY expensive 3k used. So I'm trying to see what my options are. Will a iron 5.3 directly drop in? What about an ls1? I just looking for the cheapest way to go. Any suggestions and advice is greatly appreciated. Sorry so brief but I'm on my cell.

 

[Dan_G]

Sorry to hear about another 5.3 with problems. I don't think you have many "drop-in" options here. The LH6 5.3 engine has Displacement on Demand (Active Fuel Management). So it has the additional hardware to shut down cylinders. I don't think you are going to want a used one since it would likely have it's own problems by the time you got it.

A re-manufactured LH6 is in the $3000-$3300 range and would typically have a three year warranty. Should last a good long time. Promarengine will sell you one, Rockauto has them also. There are probably other places that sell a re-manufactured LH6. If you had a local shop that could handle it, you could try a rebuild - but price wise I don't think you will do any better than a re-manufactured LH6.

I understand that this is less than Ideal. But I would probably go this route as opposed to $2K or more for a junk yard LH6 with an unknown lifespan. I also understand that a re-manufactured engine can have problems as well. Neither one is a great option.

I know that the re-manufactured 5.3L engines for the 2006 Tahoe/Yukon are like a grand less - at least partly because they do not have DoD/AFM. A used one of these engines from a 2006 model year would in theory be a pretty good place to start. The engine should bolt right in - but the sensors/wiring are not 100% identical. So you will have to deal with this. You will also have to reprogram the engine computer (PCM) to run with a non-AFM engine. It should be possible but I have not seen a post detailing all that is required to do the swap.

 

[subssonic]

Thank you for the reply. If possible I would rather tune out the DoD. From what I researched that is what got me in the situation that I'm in. My SUV was going through oil but I didn't know because the low oil senser failed. I haven't even owned this thing that long and ran through oil. Never had a warning. No light nothing. Not very happy about it.

 

[Dan_G]

Yeah, that sucks. Quite a few people have had the same issue. It would be great to drop in a used 5.3 from the Tahoe/Yukon and get some more years out of the truck. I wish I knew the details on what is different between the two engines. Someone must have done this before, hopefully they can post something.

 

[subssonic]

Could someone verify if an Iron block 5.3 will fit? And if so what all will need to be done to make it happen? I don't really care about the DoD feature or the all alluminum block.

 

[Mooseman]

One thing engine related that I can think of that might cause issues is the oil pan if it's a different mating configuration. Other than that, you will also have weight issues with the iron block with suspension and sway problems.

Have you tried car-part.com? There are a few in the $2000 range but seems only 2006 models are compatible. Don't know what the difference is with 2007-2008 but when I search for those years, both are compatible with each other and also get results from 2007-2008 1500 Silverados and Sierras.

 

[subssonic]

That's doesn't seem to save much though. I can get a reman engine for $2,899 shipped.

 

[Dan_G]

I can get a reman engine for $2,899 shipped

Yep and that's for an LH6 that is identical to the engine you are taking out. It should bolt right in and connect up to the existing wiring harness without any modification (at least in theory).

I did a quick look on eBay for a used 5.3 from a full sized GM truck. If you could get one cheap, that would be great but you would have to search for it and get a bit lucky on the timing. A quick eBay search suggests that used 5.3 engines are not cheap and many have high miles. At the upper end I'm seeing a used 5.3 from an 06 Silverado priced at $2800 with 50K miles. Used 5.3 Engines with 100K miles seem to run around $2k. That's odd since RockAuto has a re-manufactured 5.3 long block for the 06 Silverado priced less than $2K. So that kinda suggests that a re-manufactured engine is probably the lowest cots/risk option.

 

[subssonic]

Yep and that's for an LH6 that is identical with the engine you are taking out. It should bolt right in and connect up to the existing wiring harness without any modification (at least in theory).

I did a quick look on eBay for a used 5.3 from a full sized GM truck. If you could get one cheap, that would be great but you would have to search for it and get a bit lucky on the timing. A quick eBay search suggests that used 5.3 engines are not cheap and many have high miles. At the upper end I'm seeing a used 5.3 from an 06 Silverado priced at $2800 with 50K miles. Used 5.3 Engines with 100K miles seem to run around $2k. That's odd since RockAuto has a re-manufactured 5.3 long block for the 06 Silverado priced less than $2K. So that kinda suggests that a re-manufactured engine is probably the lowest cots/risk option.

Well thank you for the suggestion of Promar engines. I just called them and bought a reman from them for $2,899 shipped. 3yr unlimited

 

[Dan_G]

Best of luck on the swap. I may be doing the same thing one day.

 

[Dan_G]

Just throwing this out there. You may want to ask the folks at Promar for break-in oil recommendations. There are a bunch of "high zinc" break-in oils on the market. Some are pretty expensive. Seems like this may be a good thing but I have no experience with any of these oils. You might want to mail order the stuff so it pays to plan ahead.

PS - I noticed these break-in oils seem to be directed at engines with a flat tappet cam. I have no idea if the LH6 uses flat tappets or whether it's a roller cam. I suppose if it has a roller cam, then these break-in oils are not really needed.

 

[C-ya]

While you're doing this, get a tune to disable DOD/AFM before you even fire that new engine up!

 

[C-ya]

I have no idea if the LH6 uses flat tappets or whether it's a roller cam. I suppose if it has a roller cam, then these break-in oils are not really needed.

From the cam replacement thread, the pics show rollers.

 

[northcreek]

I used this to disable my AFM http://www.autoanything.com/performance-chips/range-active-fuel-management-disable-device?kc=GOOGADW&k_clickid=ac34b5a1-e54e-4d57-9407-91a32475039d&adgroupid=1&k_trackingid=303x35&gclid=CLv96O2bwMQCFcHm7AodRV8AyQ
works great and can be removed when you want...Mike

 

[C-ya]

northcreek, I almost went that way, but for half the price, I got way more for my money with a tune from LimeSwap.

 

[Mooseman]

I agree. The only advantage is you can reactivate it easily.

 

[subssonic]

Is there any data that proves how much fuel you save with the DoD? Because if it does save a decient amount then I'd go with the chip that northcreek bought and only use it during long highway trips. Otherwise I'll just buy a tune and have it gone forever.

 

[C-ya]

Honestly, I have not lost fuel mileage with it gone. I have tracked all my fill-ups with aCar since I bought the TB. I am averaging (long term) 13.6 mpg. It's winter now, so winter gas and idling has me around 10.5-12 these days. Last complete fill-up to measure was 10.6 mpg. DIC is at about 11.5 at the moment, and it is usually within a tenth or 2.

The added benefit is never having it kick in and start the process of the engine burning oil, which would be worth it to me to lose a few tenths in mpg over the life of the engine/truck. Since I had mine turned off, I am using less oil. I'm hoping my engine can recover and get into a "normal" consumption volume. My first oil change saw me adding 6 qts of oil between changes (5300 miles). The last oil change interval (4500 miles), I only added 3 qts. Your engine may not have suffered this malady, but it seems like a large percentage do. Sounds like something like that might have happened to you if your engine seized.

 

[northcreek]

northcreek, I almost went that way, but for half the price, I got way more for my money with a tune from LimeSwap.

I pondered going your route too. My reasons were downtime, not wanting to possibly dick-up a truck that is a strong runner,having to run high test if I got a performance upgrade with the AFM delete also if need be I can remove the device and recoup some of my $$ and/or tranfer to my next vehicle, not to mention the pretty blue glow that it gives off .
Also NYS annual inspection stations plug into your port and it gets analyzed in Albany before you pass/fail. I can unplug this before my inspection and eliminate any possible snafu,s...Mike

 

[C-ya]

Good point on the inspection. Not sure how deep they would dig (comparing tune ID's to database based on VIN or the like). No problem with that here in MI.

I opted to firm the trans shifts by shortening time and increasing pressure, decrease torque management, option to run regular or premium gas (both tables still there and updated), no speed limit (well, 300, but...), and turn off DOD. Best $100 I have spent on this truck!

 

[Dan_G]

I’m really looking forward to this engine swap. Of course, this is easy for me to say since I’m not doing the work. I have removed and replaced an engine before on an older car with a manual trans and it’s a big project. It sure feels good when it’s done. Has anyone found any videos or post that cover removal and replacement of the Envoy 5.3.

Is there any data that proves how much fuel you save with the DoD

I got a replacement tune from PCM on NC with DoD disabled. I probably lost 1-2 mpg on the highway. Not a big deal. From my perspective it's just not worth the potential oil consumption problems regardless of fuel cost - so it's gone. Since your engine will be brand new I'm not sure it even matters (so long as you can keep it full of oil). The new engine should last 100K easy with or without Dod. So we are talking about 6 - 7 years from now depending on how much you drive (the truck will be like 15+ years old). If it were me, I would want Dod disabled from the very beginning, just to minimize the chance of oil consumption problems. But this probably only make sense if you can spare the cash to get the tune done.

 

[C-ya]

If it were me, I would want Dod disabled from the very beginning, just to minimize the chance of oil consumption problems. But this probably only make sense if you can spare the cash to get the tune done.

Costs $100.00 plus postage to Jeremy @ Lime-Swap. You would have time during the swap.