Hybrid Tahoe Engine Swap

[braveheartwallace]

I have a 2009 Tahoe Hybrid that recently passed 200,000 miles. Around 150,000 the electric drive train was completely refurbished by my Chevy dealer due to a "Hybrid Error."

A day after turning over 200,000 the vehicle barely started and when it did there was a loud explosion and violent shaking. Previously I had suspected the hybrid system of failing (electric motor, transmission, etc.) and believed the problem was hybrid related. I was wrong.

The car was towed to a Chevrolet dealer for a close inspection. The mechanics determined the engine has been rendered useless with “a destroyed oil pump, catalytic converter, and additionally it had no compression whatsoever.” They quoted $10,000 for a new engine and installation.

As some of you know, the hybrid Tahoe has a unique drive train of a GM Vortec 6.0L V8 mated to the GM 2-mode hybrid system. The 2-mode hybrid system takes the place of the standard GM transmission, it is made up of two electric motors, that use the same space as GM’s standard six-speed automatic transmission.

I'm trying to figure out if it would be possible to completely remove the hybrid drive train and replace it with a stock GM Vortec/LS derivative engine and transmission. From my research, the engine and transmission share the same dimensions of most General Motors engine/transmission units, however I bet they have different engine/transmission mounts. This might require some custom fabrication.

One mechanic at a custom fabrication shop said he can't imagine there would be any need for custom fabrication of anything, and production parts should be readily available. As long as we get a good donor engine/trans/harness/ecm/tcm etc, it should be straight forward.

I know the braking system, AC compressor, and power steering may need to be exchanged as well as they are electrically driven on the hybrid Tahoe and engine driven on your standard Tahoe.

I know a guy who took the Hybrid drive train out of a totaled Hybrid Tahoe and put it in a 1957 Chevrolet Bel Air, so it seems it may be possible to do the reverse. (Unfortunately he is unable to take on this project.)

Let me know your thoughts and if this project may be be possible.



Side note: I also own a 5.3L 2001 Tahoe (250,000 miles) and am impressed that it has outlived the 2009 Hybrid despite both being regularly maintained.

 

[dubyagee01]

So whats so special about the 6 liter that would stop a junkyard engine from dropping in? Seems a no brainer with a refurbed hybrid drive.

 

[braveheartwallace]

So whats so special about the 6 liter that would stop a junkyard engine from dropping in?

I don't know if that would be possible. I'd have to find a hybrid Tahoe donor for an exact engine replacement in order for the engine to fit the wire harness and communicate with the hybrid control computer. The engine/trans, required harnesses, and ecm/tcm are all different on the non hybrid Tahoe.

 

[dubyagee01]

The existing harness should swap to the replacement engine as should all the external parts. Unless its a hybrid only block which I doubt.

 

[braveheartwallace]

The existing harness should swap to the replacement engine as should all the external parts. Unless its a hybrid only block which I doubt.

Do you think it would be possible to swap the damaged Vortec 6L for a commonly found Vortec 5.3L using the original wiring harness on the smaller engine?

I've also emailed a couple GM engine swap experts.

 

[Doubeleive]

exactly why the hybrids are generally cheap on the used market, good luck, seems like a lot of hassle to me

 

[lt1gmc]

A few potential problems: The Hybrid has a unique camshaft to be more efficient with the hybrid assist. So the ECM engine control programming would not be right, same as with with using a 5.3, the calibration would not be right. The second thing is it would need to had AFM cylinder deactivation to work right. Another issue will be the fact the AC compressor is mounted inside the intake valley and is electric, not belt driven. There are quite a few things that make the job easier if you used a hybrid spec shortblock.

 

[braveheartwallace]

Update: Hybrid Tahoe is in the shop getting its gas engine completely overhauled/rebuilt.

I decided not to run the overly complicated procedure of preforming a heart transplant.

 

[dnt1010]

I know this is an older thread but I am curious how everything worked out and how much it ended up costing to do the rebuild? Sounds like the way to go if the cost is not too high? Not seeing a lot of GM 6.0 LFA remanufactured engines available on the internet, I actually only found some high mileage used ones..............

 

[BG1988]

I have a 2009 Tahoe Hybrid that recently passed 200,000 miles. Around 150,000 the electric drive train was completely refurbished by my Chevy dealer due to a "Hybrid Error."

A day after turning over 200,000 the vehicle barely started and when it did there was a loud explosion and violent shaking. Previously I had suspected the hybrid system of failing (electric motor, transmission, etc.) and believed the problem was hybrid related. I was wrong.

The car was towed to a Chevrolet dealer for a close inspection. The mechanics determined the engine has been rendered useless with “a destroyed oil pump, catalytic converter, and additionally it had no compression whatsoever.” They quoted $10,000 for a new engine and installation.

As some of you know, the hybrid Tahoe has a unique drive train of a GM Vortec 6.0L V8 mated to the GM 2-mode hybrid system. The 2-mode hybrid system takes the place of the standard GM transmission, it is made up of two electric motors, that use the same space as GM’s standard six-speed automatic transmission.

I'm trying to figure out if it would be possible to completely remove the hybrid drive train and replace it with a stock GM Vortec/LS derivative engine and transmission. From my research, the engine and transmission share the same dimensions of most General Motors engine/transmission units, however I bet they have different engine/transmission mounts. This might require some custom fabrication.

One mechanic at a custom fabrication shop said he can't imagine there would be any need for custom fabrication of anything, and production parts should be readily available. As long as we get a good donor engine/trans/harness/ecm/tcm etc, it should be straight forward.

I know the braking system, AC compressor, and power steering may need to be exchanged as well as they are electrically driven on the hybrid Tahoe and engine driven on your standard Tahoe.

I know a guy who took the Hybrid drive train out of a totaled Hybrid Tahoe and put it in a 1957 Chevrolet Bel Air, so it seems it may be possible to do the reverse. (Unfortunately he is unable to take on this project.)

Let me know your thoughts and if this project may be be possible.



Side note: I also own a 5.3L 2001 Tahoe (250,000 miles) and am impressed that it has outlived the 2009 Hybrid despite both being regularly maintained.

the issue is these engines require the oil to be fresh and clean 5-7k oil change interval is too far apart..

2500-3000 (3500 at the most) miles oil changes are the ideal spot. for these engines.... anything less is asking for trouble

 

[dnt1010]

The GM Two Mode vehicles are obsolete. Total of only around 33,000 produced Yukon/Escalade and Tahoe 2007 through 2013 model years. In the next 5 to 10 years parts will be nearly impossible to source. Maybe the next Democrat president will resurrect the Obama "Cash for Clunkers" program so that we can rid ourselves of this vehicle plague.................... haha I am just kidding I would not take 15k for my old worn out **. She is my favorite truck of all time. Reminds me of the news story about the lady that had an older sick cat, turns out that the cat had Luekemia and she spent $25,000.00 on vet treatments. IT STILL DIED!

 

[BG1988]

The GM Two Mode vehicles are obsolete. Total of only around 33,000 produced Yukon/Escalade and Tahoe 2007 through 2013 model years. In the next 5 to 10 years parts will be nearly impossible to source. Maybe the next Democrat president will resurrect the Obama "Cash for Clunkers" program so that we can rid ourselves of this vehicle plague.................... haha I am just kidding I would not take 15k for my old worn out **. She is my favorite truck of all time. Reminds me of the news story about the lady that had an older sick cat, turns out that the cat had Luekemia and she spent $25,000.00 on vet treatments. IT STILL DIED!

the easiest part to find will be the battery pack. because it uses the same cells as the prius can swap directly from the prius battery so it will be easy to rebuild it for a 1000$

 

[dnt1010]

The battery technology is fascinating. I just ordered a replacement with "supposedly" new modules and have my old one out and on the work bench doing some testing. Bought this sweet Turnigy Reaktor balance charger currently on #7 of 40 modules so no definitive results just yet.
It takes about 5 hours for the balance charger to complete 2 dischareg / charge cycles so might be a couple weeks before I complete my research. Just wish I had brand new battery to compare my results to.......the metal case on the replacement hybrid battery pack has case seals and if I break them to test modules, my wararnty is voided. Dang It maybe I can start a gofund me page and get up the $2,789.00 to cover the cost and then I can bust off the seals and test without remorse.

 

[BG1988]

The battery technology is fascinating. I just ordered a replacement with "supposedly" new modules and have my old one out and on the work bench doing some testing. Bought this sweet Turnigy Reaktor balance charger currently on #7 of 40 modules so no definitive results just yet.
It takes about 5 hours for the balance charger to complete 2 dischareg / charge cycles so might be a couple weeks before I complete my research. Just wish I had brand new battery to compare my results to.......the metal case on the replacement hybrid battery pack has case seals and if I break them to test modules, my warranty is voided. Dang It maybe I can start a gofund me page and get up the $2,789.00 to cover the cost and then I can bust off the seals and test without remorse.View attachment 217183

I have seen a used one on ebay the seller claimed 60,000 miles for 750$ i'd would offer him less maybe 450..

www.ebay.com/itm/183687525059

 

[dnt1010]

Almost done with testing the modules in my old battery. 36 out of 40 done, overall average so far is around 20% capacity (1,300 aMH) of what a new battery is rated at (6500 aMH). I am really itching to pull the top off the New battery pack and test a couple of modules to see if they are in fact NEW LOL
Apparently the GM battery management system is very ******* these modules. If you buy a used pack even at low mileage it will probably have all toasted modules. Toyota Prius systems are supposed to be much more gentle on the batteries but they only hold 28 modules and you would have to buy 2 packs. Most of the used battery sellers like GreenBean are rebuilding these GM packs with old Prius modules, knowing that the GM battery management will not throw a code until the old used batteries are toasted to basically zilch so they will rarely have to warranty the product and the poor owner just drags around with a crappy battery in their ride for years. After doing research it appears to be a big scam, they are charging people 3k for a battery pack with used modules! Just my opinion, maybe they are in fact angels here to save all us GM Two Mode Hybrid owners LOL

 

[BG1988]

Almost done with testing the modules in my old battery. 36 out of 40 done, overall average so far is around 20% capacity (1,300 aMH) of what a new battery is rated at (6500 aMH). I am really itching to pull the top off the New battery pack and test a couple of modules to see if they are in fact NEW LOL
Apparently the GM battery management system is very ******* these modules. If you buy a used pack even at low mileage it will probably have all toasted modules. Toyota Prius systems are supposed to be much more gentle on the batteries but they only hold 28 modules and you would have to buy 2 packs. Most of the used battery sellers like GreenBean are rebuilding these GM packs with old Prius modules, knowing that the GM battery management will not throw a code until the old used batteries are toasted to basically zilch so they will rarely have to warranty the product and the poor owner just drags around with a crappy battery in their ride for years. After doing research it appears to be a big scam, they are charging people 3k for a battery pack with used modules! Just my opinion, maybe they are in fact angels here to save all us GM Two Mode Hybrid owners LOL

there is some better modules out there with lower ESR (Equivalent series resistance) ratings


2k1Toaster on Prius chat.. it's 2800 for new custom made 20 modules.(40 module equivalent )


i wonder if anyone has figured out a way to use several battery packs in parallel. maybe even capacitors in parallel to smooth out the ripple and peak discharge current upon moving.. you would need about 110 2.8-3.0volt super captors
or if you want the 3v ones it 7700$ not including anything else
$5400 for Prebuilt module... 144x2.7v modules



I wonder if it would be possible to convert it directly to capacitors and do away with the battery pack it self.. since they can discharge and charge much faster the only issue I see is keeping a float charge but that can be solved with using flexible solar panels on the body.

 

[randeez]

Skimmed thru, but just an fyi for future use.... the hybrid uses a different operating system than normal, I saw where someone pulled the tune with hpt but most of the tables werent populated or even available. Afaik, there is no way to modify the stock tune with hptuners/efilive, I doubt a dealer is going to custom tune for a different engine. So the only engine that can be put back in it is another from a 6.0 hybrid, no deleted dod/vvt, different displacement, etc

 

[BG1988]

Skimmed thru, but just an fyi for future use.... the hybrid uses a different operating system than normal, I saw where someone pulled the tune with hpt but most of the tables werent populated or even available. Afaik, there is no way to modify the stock tune with hptuners/efilive, I doubt a dealer is going to custom tune for a different engine. So the only engine that can be put back in it is another from a 6.0 hybrid, no deleted dod/vvt, different displacement, etc

it can be converted back to a reg tahoe

but you will need a BCM and ECM as well as the engine and transmission...
that will convert it back..

the 2 mode is just a drop universal in replacement..


you can drop in a Hemi V8 if that is your cup of tea


5.7 L (345 cu in) Hemi V8 from a Chrysler Aspen

• 2009 Hybrid - 5.7 L (345 cu in) Hemi V8, 399 hp (298 kW) at 5200 rpm and 390 lb⋅ft (529 N⋅m)