Engine Swap 5.3 -> 6.2 (L9H) 2009 CC k1500

mike187 · July 6, 2016

posted this at the end of the above sticky L9H questions, but I thought I'd better start my own thread in case that gets overlooked.

I've been doing my research on the internet and I've decided to upgrade my 2009 GMC Sierra k1500. it's a crew cab and currently has the 5.3/6-speed. 5.3 has about 53k miles on it, it's been a great engine, I just want more power to pull my wakeboard boat on the hills and I don't want to boost or cam my current 5.3. I already drove the 6.2 and love it!!

I'm looking at a brand new GM crate engine L9H, but there are a few things that I haven't been able to find yet. So far, I know I need a new intake manifold & fuel injectors. The fuel rails are off by a single digit at the end of the part #, but I think I've narrowed it down to a mounting issue from the 5.3 to the 6.2 rails.

here are my specific questions which will relate to a parts list:

- since I'm ordering a new engine w/o DOD (active fuel management), I know i'll have an extra sensor at the rear of the engine that i'll simply leave unplugged. but now I'm picking up an extra sensor for the VVT on the new engine. what are my options with this? do I need a new sensor? or am I completely wrong and my current 5.3 has VVT and just don't know it....

- will my 2009 ecm (computer) work with the new engine? the parts guy at the dealer says they're 2 different part numbers, but he thinks it's just because of the year difference (he's going off of a 2012 truck) btw, I know i'll have to get it flashed. going to have the dealer do the 6.2 flash on hopefully the existing computer.

- last, before I do the flash and provided my stock computer works with the new engine, can I start it up after the new engine install? will it actually turn over with the old 5.3 engine programming? I'm asking to see if I can SAFELY drive it to the dealer to have the ecm flashed or if I need to have it towed.

if there's anything I missed (parts, etc...) please let me know. from everything I've came across so far, it's a pretty straight forward swap. i'll take any advice from people that have done it in the past. i'll be sure to post up pics & progress from my swap.

thanks in advance

Mike

efritz · July 7, 2016

First off, this isn't a dealer kind of thing, they don't usually take to well to this kind of work, you're better off at an independent performance shop. Also, it would be best to tune it with a custom tune to optimize your setup a bit. I would not run or drive it until you get all of the tuning done, it is more important than the swap on a newer vehicle. Your current 5.3 has VVT. IMO just go buy a truck with a 6.2, it will be easier, cheaper, and better,,, not to rain on the performance parade.

Chris · July 7, 2016

Easy swaps stopped in 07 when the body changed. I think the motor mounts are pretty different for the 6.2

mike187 · July 7, 2016

First off, this isn't a dealer kind of thing, they don't usually take to well to this kind of work, you're better off at an independent performance shop. Also, it would be best to tune it with a custom tune to optimize your setup a bit. I would not run or drive it until you get all of the tuning done, it is more important than the swap on a newer vehicle. Your current 5.3 has VVT. IMO just go buy a truck with a 6.2, it will be easier, cheaper, and better,,, not to rain on the performance parade.

i'll be getting a custom tune from blackbear performance in the coming months. the engine will be a stock 6.2 litre so the dealer can definitely take care of that. already called on it, they can flash my current ecm in 30 min and the cost is $65.

a new truck with the same features will be north of $52k. mine is paid off now, and the swap will cost me just a hair over $5k. plus it'll be a fun project!

could you provide me the proof where you found my current 5.3 has VVT? i've read so many conflicting things online and i'm just trying to find rock-solid proof. thanks!

Easy swaps stopped in 07 when the body changed. I think the motor mounts are pretty different for the 6.2

motor mounts are identical between the 5.3 & 6.2 of the same generation. everything is identical except for 3 parts (so far that i've found)

efritz · July 9, 2016

Yeah, it should bolt right in... and if the dealer is willing to do the work (you must have a very good dealer) then go for it i guess. You can find out if the 5.3 has vvt by looking for the PWM wires and phaser support on the timing cover. yours being an 07 actually may not. the exhaust is different between the two I believe... just put a nice borla setup in

wslr85 · July 9, 2016

I did engine swap few months ago, 2011 5.3l to 2009 6.2l

Well, the engine will mount right in place, i used the same ecm, wiring and all the 5.3's stuff, the only must do things you need for the swap are:, intake manifold, fuel rail, injectors. Optional( starter, battery, exhaust manifold and catback, airfilter.

In my case I couldn't drive it because my ecm was programed with AFM, the socket was un plugged.

I took my car to the dealer to replace the tune to 6.2 but the programming failed to communicate with the transfercase, engine was running fine but no communication with the gearbox so the car didnt move!! Many tries but all failed even when programing the gearbox to 6.2. So i towed it agin to a performance shop and did a tune with hp tuner & deactivate AFM. And the swap was successfully done...

All the best to you & good luck,, hope I didn't miss an important info

U can msg me if more info needed, glade to help

The info I wrote are from my experiment, im not an expert

mike187 · July 11, 2016

I did engine swap few months ago, 2011 5.3l to 2009 6.2l

Well, the engine will mount right in place, i used the same ecm, wiring and all the 5.3's stuff, the only must do things you need for the swap are:, intake manifold, fuel rail, injectors. Optional( starter, battery, exhaust manifold and catback, airfilter.

In my case I couldn't drive it because my ecm was programed with AFM, the socket was un plugged.

I took my car to the dealer to replace the tune to 6.2 but the programming failed to communicate with the transfercase, engine was running fine but no communication with the gearbox so the car didnt move!! Many tries but all failed even when programing the gearbox to 6.2. So i towed it agin to a performance shop and did a tune with hp tuner & deactivate AFM. And the swap was successfully done...

All the best to you & good luck,, hope I didn't miss an important info

U can msg me if more info needed, glade to help

The info I wrote are from my experiment, im not an expert

Thank you very much for the info, this is exactly what I was hoping to find; someone who's done this instead of people telling me not to!

appreciate the advice! and the parts list, you confirmed everything for me. the fuel rails were my last iffy part, we couldn't figure out if we really needed to replace them or not, apparently there is a slightly different mount on the 6.2 rails vs the 5.3, but otherwise, they're the same.

I'm planning on doing the full tune. I was going to bring it to the dealer for the stock 6.2 L9H tune (w/o the AFM) i'll see if I can start mine up and put it into gear after I do the swap. if not, i'll just send off my ecm for the custom tune.

I take it since you went from a 2011 5.3 you used the stock cam from the 6.2 and kept your VVT?