6.0 Swap Time!

[Echo]

I'm putting an LQ9 6.0 from a 2003 Escalade (8th Vin N) in my 2002 Tahoe. The L59 5.3 in it has 280k on it, and its making some ungodly noises that sound a lot like bad rod bearings or crankshaft bearings. Keep in mind, i'm no expert mechanic, i'm just quite mechanically inclined. I've rebuilt 2.2 and 4.8 engines before, and swapped out many others. However, i've never done a 6.0 swap.

I keep finding a lot of conflicting information in regard to PCM flashing and compatibility. I'm trying to find out if its possible to flash the 02 5.3 PCM for the 6.0 engine, or alternatively, find a compatible 6.0 PCM to flash with my 02 Tahoe VIN.

I don't think i would need a new wiring harness, most information seems to point to 100% compatibility for that, but i still keep finding some accounts of people having to swap those as well.

If someone could point me in the right direction to figure this out, i would greatly appreciate it.

Any tips or advice are welcome.

 

[Mudsport96]

It will swap in using all your existing stuff. And will run fair on the stock tune.. not optimally, but fair. ( ON GASOLINE not on e85)
As for a tune, the stock computer is tuneable for a 6.0. The real question is are you going to tune it or have a tuner shop do it. The stock injectors will run a 6.0 fine on gasoline, but most likely be too small for a 6.0 on e85. Plus you would have to either change the injectors for stock 6.0 injectors if you wanted a stock 6.0 tune without flex capability, OR change the injector data in the stock 6.0 tune to the L59 injector data since the flex injectors are bigger than 6.0 injectors. Or bigger injectors and change the data in the tune to that info for a 6.0 with a flex tune.

 

[strutaeng]

Welcome to the family!

Yeah, everything is pretty much plug-and-play on the wiring. No modifications needed on that.

Just the tune is different, but your computer can easily be reflashed for the 6.0

 

[Marky Dissod]

Your L59 is a physical throttle. What is the LQ9: physical or signal throttle?
If the LQ9 is physical throttle, bob's your uncle.

If the LQ9 is signal throttle, then:
IFF the 12200411 can drive a signal throttle, then yes, program your pcm for the LQ9.
Otherwise you need a pcm that can drive a signal throttle.

Use L59 injectors on the LQ9; don't use E85 til you upgrade the injectors again.

I very much doubt you'll find a tuner with brass 8@11$ big enough, to tune an LQ9 ...
an LQ9 with the L59 heads you already have on the LQ9. My tuner flat declined.

 

[Echo]

I should mention this 6.0 engine comes complete. Fuel rails, injectors, all accessories and components that came with it. I don't think i've ever put e85 in the 5.3.

I have no knowledge on tuning, and wouldn't even know where to start. I planned on sending the computer out to be reflashed, but haven't looked around for anyone to do it just yet.

As for the throttle, my 5.3 is a cable throttle, and it appears the 6.0 is not. Would that present me any problems? Could i reuse the throttle body from my 5.3, or find a cable-operated 6.0 throttle body?

I'm glad to hear that it should be a straight-forward swap. The only difficulty it seems i will have is finding an engine hoist tall enough to remove/install. It has a 7 in. lift.

 

[strutaeng]

I should mention this 6.0 engine comes complete. Fuel rails, injectors, all accessories and components that came with it. I don't think i've ever put e85 in the 5.3.

I have no knowledge on tuning, and wouldn't even know where to start. I planned on sending the computer out to be reflashed, but haven't looked around for anyone to do it just yet.

As for the throttle, my 5.3 is a cable throttle, and it appears the 6.0 is not. Would that present me any problems? Could i reuse the throttle body from my 5.3, or find a cable-operated 6.0 throttle body?

I'm glad to hear that it should be a straight-forward swap. The only difficulty it seems i will have is finding an engine hoist tall enough to remove/install. It has a 7 in. lift.

Just swap the throttle body to keep things simple.

You could just swap the entire intake with injectors and fuel rails (this solves issues with return vs returnless fuel if that's the case.) Just tell the guy tuning the computer which injectors you are running so they can get the flowrates correct. The L59 injectors are higher flowrates vs the non-flex fuel LS engines in that generation. A lot of guys run those as budget high performance options when running big power.

My 99 Silverado got an V6 to L59 swap and I'm running a LM7 stock tune. I just tweaked the injector flowrate using HP Tuners because truck ran a bit rich, although I drove it like that for 3 years.

 

[rockola1971]

Or just buy a Yukon Denali!!!! I couldnt resist.

 

[Marky Dissod]

Start looking for the tuner now. The difference between a good tuner and a great one is the difference between merely useful & fun.
Difference between a good tuner and a bad one is the difference between merely useful & divorce.
Nothing against Black Bear, but don't just stop there, do more research.

If you don't find that tuner, yes, the difference between cable & signal throttle will be a problem.
Maybe better to stick to cable throttle, which will let you keep your pcm.

Since LQ9 injectors will not gain you any MpG or performance benefit, use L59 injectors.

Is LQ9 you got returnless or return fueling?

 

[Mudsport96]

So the 5.3 tune will have different specs for the injectors. You will have to use the 5.3 intake, fuel rails and injectors on the 6.0. Not a big deal, and it will let you drive the rig till you get a tune.

 

[strutaeng]

I would probably replace the rear main seal on the swapped engine. That's one thing I wish I did on my 99 Silverado and I think it's starting to leak slightly (I just did the oil pan and pickup tube o-ring.) These seals start leaking with age and high mileage.

Probably I would do a complete seal kit since engine will be out: valve covers, valley cover, front main, rear main, oil pan, and pickup tube.