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Engine swap?????

11K views 17 replies 5 participants last post by  Goostoff 
#1 ·
I have an 07 with the 3900 AFM engine in it. Can I replace iit with an 06 3900 without the AFM and just have the dealer re program the computer?

Been doing searches for a couple weeks now and there just isnt much info out there on the subject. Anyone ever done it or any GM techs out there that know anything about the computer part of it. I am almost certain that the engine will bolt right in and everything hook up but I needf to be sure beforew I lay out the cash for an engine.
 
#3 ·
A DOD engine is over twice the money. I found an 07 DOD engine for $950 with 160k where I can get an 06 non DOD engine with 73k on it for $400.

I keep seing this dod delete kit but the chevy dealer has never heard of it. It looks like it just makes a dod engine a normal engine. Hopefully someone will chime in that has a definative answer. Thanks for your response.
 
#4 ·
#6 ·
I dont have a perfectly good engine. The cam is toast from the dod system. It costs more to fix the engine that to replace it with an earlier version. Thats the reason for the swap


I am working on swapping a 10 3.9 from a salvaged 9c1 into a 07 9c1.So far the two engine harnesses have different plugs. The purple ones near the brake booster do not match up at all.In the next few weekends I should have some progress in the swap.Ill post pic of it in a new thread.
 
#7 ·
Why swap in a 06 3900 when you can just swap in a 2010-2011 3900, if your bent on keeping the variable upper you can just swap that around. As far as physical differences there is none, any 3500/3900 will be 100% bolt on.

I changed from a 3500 to a 3900, I know another member on this forum went from a 3900 with AFM to a 3500. The only thing that would limit you would be the tune but Will at Overkill Motorsports would have you covered.

Going back to the variable upper intake, I'd ditch it if I were you when you pick up another 3900 engine. GM had a lot of problems with it and that's why they pitched it in the 2010-2011 impala models, I even contacted Ben at WOT-Technologies who does bench flow testing and port/polish work and he stated that the upper restricts flow.

I did a bunch of research on the 3500/3900 though trail and error going though around $3000 in the process as there's hardly any info on these engines, I honestly think the 3900 is the best engine that was ever put into the 8th gen impala.
 
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#9 ·
I did a bunch of research on the 3500/3900 though trail and error going though around $3000 in the process as there's hardly any info on these engines, I honestly think the 3900 is the best engine that was ever put into the 8th gen impala.


Agreed. I really like the 3.9L engine on my Impala. It has plenty of power and doesn't have the DOD, since its a 06. Seems like a very strong and powerful pushrod engine, and it works well with the 4T65E transmission. :)
 
#8 ·
Thank you both for the response.

nhgonzo....I assume your 07 is the dod engine and you are getting rid of that system? I just looked under the hood on mine and the 2 plugs you are refering to will not affect me. They will not even be unplugged in my case.

fatrabbit.... This is exactly what I am wanting to do. From what I understand the 07 and 08 were the only engines that have the AFM system. I want to get rid of it and never worry about it again. The reason why I am asking about the 06 is because I have found an 06 3900 from a G6 GTP with about 78,ooo on it for just over $400. I think I am going to call the salvage yard and get them to start pulling it.
 
#10 ·
Goostoff- That's a really good price on a 3900, when I swapped in my first 3900 I paid $700 with it having around 25,000 miles, the second 3900 I swapped in I also paid $700 and that had around 70,000 miles. You won't have to swap around the harness, just reuse yours and leave the 2 plugs to the AFM and variable upper intake unplugged and get retuned by Will. You'll love what Will's tuning will do to your car ;)

Dave_N- I'm still trying to trade my 2012 Impala for a 2010-2011 LTZ but the 10-11 impala are hard to find by me, I think those were the best years for the 8th gen Impala as a lot of the bugs were worked out by then. The 3500/3900 offered good reliable power, the engines are cheap to replace and easy to tare down and get at everything. There extremely quiet too in good working order and they weren't over rated for the transmission, if I got back to that platform I'd continue were I left off.
 
#11 ·
Dave_N- I'm still trying to trade my 2012 Impala for a 2010-2011 LTZ but the 10-11 impala are hard to find by me, I think those were the best years for the 8th gen Impala as a lot of the bugs were worked out by then. The 3500/3900 offered good reliable power, the engines are cheap to replace and easy to tare down and get at everything. There extremely quiet too in good working order and they weren't over rated for the transmission, if I got back to that platform I'd continue were I left off.


I'm keeping my 06 Impala until it either gets totaled or too old to maintain. I only have 85000 kms on it and it runs great for a nearly 10 year old car. Hope you can find a decent one. :)
 
#12 ·
Well with all the messing around the engine I was after got sold. They do have another one with a few more miles on it for the same money so I am going to be ordering it this afternoon. With any luck I can find time this weekend to put it in and haul it to the dealer next monday for a program change.
 
#13 ·
Well I have finally found enough time to do my swap. This weekend she gets done. Got the shop all cleaned out and no appointments after noon tomorrow. As long as the phone doesnt start ringing off the hook I hope to get it done some time Saturday. The G6 engine has a few different parts on it that I am goig to have to swap out. Hopefully it will just turn out to be the upper intake, coolant fill cap , and oil filter adapter..
 
#14 ·
Well I got the boat anchor out yesterday. Daughter has graduation today and parties to attend this afternoon. Hoping to at least get all the crap sw2apped onto the new engine and set in place tonight. Tomorrow I am planning to get everything hooked back up and see if it will even run. I'm hoping it will run fine and just have the CEL on so I dont have to haul it to the dealer for flash
 
#15 ·
My swap is complete. I finished it up yesterday afternoon. As expected my CEL is on. It is giving me 2 codes at the moment stating that cyl 1, and cyl 5 are disabled. I just need to call the dealer now and get it scheduled for PCM reporogram. As I am sitting here I am beginning to wonder why I cant just get a PCM from an 06 and install it. Wouldnt this do the same thing and save me the hassle of the dealer?
 
#16 ·
Its probably better to just have GM flash the latest ECM program, to avoid any other issues. I'm glad the G6 engine works so far and congrats on swapping the engine. Hope your car runs good now. :)
 
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