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