Engine swap questions
#1
02-22-2019, 09:10 AM
Engine swap questions
This is a few weeks premature but I'm trying to wrap my head around an engine swap from an 04 into an 03. The 03 VIN is SALTY16xxx.... and the 04 is SALTY19xxx... Both are Bosch 4.6 SAI engines. Are there any other differences between a 6 and a 9 engine that I need to be concerned with? As a side note, this is a death VIN truck and the oil pump recently failed and grenaded the engine.
The 03 does not have a FOB, and I'd like to retain the mileage on the engine versus the chassis (despite the chassis being lower) so I'm thinking of bringing the cluster with the engine. Here's what I've learned from the RAVE about the components I believe will have to come with the engine to accomplish this.
I'm interested in hearing the plusses and minuses of my concept from those of you who have done this sort of thing, as well as additional tips or whatchouts that are lurking out there. The engine swap itself seems pretty straightforward. I may bring the trans and transfer case over due to the lower mileage, and will bring the CDL lever. I realize the door cylinder and ignition will have to come over too in order for the FOB to work. The alternative would be to live with the mileage discrepancy and simply get my current FOB reprogrammed and re-keyed. This approach seems simpler and may have other advantages that aren't apparent to me but I also like the additional challenge of the full conversion. I think. I know a lot of you guys can do this in your sleep so I'd sincerely appreciate an education.
Thanks,
Aaron
The 03 does not have a FOB, and I'd like to retain the mileage on the engine versus the chassis (despite the chassis being lower) so I'm thinking of bringing the cluster with the engine. Here's what I've learned from the RAVE about the components I believe will have to come with the engine to accomplish this.
- The SLABS ECU, attached to a bracket behind the front passenger glovebox.
- Body Control Unit (BCU), located behind the passenger glovebox and connected to the main harness by four connectors on its bottom edge and an additional connector located on the side of the BCU casing.
- The IDM, integrated into the passenger compartment fuse box, which is mounted behind the fascia below the steering column. (I haven't looked but don't know WTF this is)
- The engine control module (ECM), located on the RH side A post below the face panel inside the vehicle.
I'm interested in hearing the plusses and minuses of my concept from those of you who have done this sort of thing, as well as additional tips or whatchouts that are lurking out there. The engine swap itself seems pretty straightforward. I may bring the trans and transfer case over due to the lower mileage, and will bring the CDL lever. I realize the door cylinder and ignition will have to come over too in order for the FOB to work. The alternative would be to live with the mileage discrepancy and simply get my current FOB reprogrammed and re-keyed. This approach seems simpler and may have other advantages that aren't apparent to me but I also like the additional challenge of the full conversion. I think. I know a lot of you guys can do this in your sleep so I'd sincerely appreciate an education.
Thanks,
Aaron
#2
02-22-2019, 01:00 PM
Rock Crawling
If you're doing an engine swap, there is NO NEED TO SWAP ANY COMPUTERS All Bosch motors are interchangeable with bosch trucks(4.0, 4.6, SAI, non-SAI) with some minor caveats. Those being, you would need access to an Autologic or other capabale scanner to tell the ECU that you have changed engine size(There is literally a toggleable setting for which displacement you have) and if you are changing between SAI and non-SAI you will get a CEL if you do not have the right equipment. The car will run just fine, but the emissions computers will not be happy. In that case you would need the matching ECU transferred, and unless you have access to an Autologic or other high level scanner to marry the BCU and ECU, you would need to transfer the cluster, ECU and BCU to make them all happy about the odometer readings.
The computer under the drivers seat is the TCU(Transmission) and does not need to be changed for any reason.
There is NO reason to swap any ignition or door lock cylinders for an engine swap or computer swap either. They have no intelligence and no coding attached, they are purely electromechanical.
You say the car has no "FOB" do you mean the keys have no buttons on them? These cars have integrated keys with the remote transmitter. No separate "FOB". If you would like working remote transmitters you can get new ones on eBay or from the dealer, or used ones as well. If you go new on eBay, make sure you get genuine as the cheap chinese ones are 433.4mHz frequency and our trucks are 315mHz frequency. Not compatible.
Any used transmitter can be synced up to your car with an autologic or high level scanner. You may need the "barcode" that comes with the new key, or you may be able to get away with just the 6 digits that are on the sticker on the circuit board. It depends on your method
The computer under the drivers seat is the TCU(Transmission) and does not need to be changed for any reason.
There is NO reason to swap any ignition or door lock cylinders for an engine swap or computer swap either. They have no intelligence and no coding attached, they are purely electromechanical.
You say the car has no "FOB" do you mean the keys have no buttons on them? These cars have integrated keys with the remote transmitter. No separate "FOB". If you would like working remote transmitters you can get new ones on eBay or from the dealer, or used ones as well. If you go new on eBay, make sure you get genuine as the cheap chinese ones are 433.4mHz frequency and our trucks are 315mHz frequency. Not compatible.
Any used transmitter can be synced up to your car with an autologic or high level scanner. You may need the "barcode" that comes with the new key, or you may be able to get away with just the 6 digits that are on the sticker on the circuit board. It depends on your method
#3
02-22-2019, 01:46 PM
Thanks Llama! Much appreciated. 
I get that I don't HAVE to swap any computers but my goals are more than just an engine swap. Since I don't have a scanner and prefer not to pay someone to do the reprogramming, my plan was to use the 04's key in the 03. I was using the term FOB interchangeably to mean the integrated transmitter in the factory key (the one with the buttons...). I probably should have just said "factory key". The new truck comes with a hardware-store key only. I also own a key-cutting machine so I could simply cut a new blank and slide it into the old "FOB", and not change the hardware in the door/column but this would still require reprogramming, and I wouldn't get the cluster this way either. I'll leave the TCU in place.
From what you've written it sounds like I'm on the right track and can accomplish the whole thing in my shop. As I said, swapping all the computers was a way for me to retain the cluster and the original factory key from my 04. While it may not be the easiest method, swapping a few little metal boxes seems like a pretty small amount of scope creep when considering the magnitude of the rest of the swap, and what I get for it. I just wanted to confirm that these were the components I needed and to ensure I wasn't overlooking anything.
I get that I don't HAVE to swap any computers but my goals are more than just an engine swap. Since I don't have a scanner and prefer not to pay someone to do the reprogramming, my plan was to use the 04's key in the 03. I was using the term FOB interchangeably to mean the integrated transmitter in the factory key (the one with the buttons...). I probably should have just said "factory key". The new truck comes with a hardware-store key only. I also own a key-cutting machine so I could simply cut a new blank and slide it into the old "FOB", and not change the hardware in the door/column but this would still require reprogramming, and I wouldn't get the cluster this way either. I'll leave the TCU in place.From what you've written it sounds like I'm on the right track and can accomplish the whole thing in my shop. As I said, swapping all the computers was a way for me to retain the cluster and the original factory key from my 04. While it may not be the easiest method, swapping a few little metal boxes seems like a pretty small amount of scope creep when considering the magnitude of the rest of the swap, and what I get for it. I just wanted to confirm that these were the components I needed and to ensure I wasn't overlooking anything.
#4
02-22-2019, 04:17 PM
Rock Crawling
eh... I feel like the swapping of the computers to get a working key fob is going the hard way. It should only cost 0.5 hour labor at a rover shop(if even that) to program the "new" key to your old car. I would buy an ebay key blade/remote shell, have it cut to your existing key, and transfer the key fob circuit board into it, followed by a quick trip to a shop to program.
Doing it the other way would be like using kitchen shears to give yourself a hair cut to save from going to the barber. Ya, it's possible... but is it the best way? nah.
Doing it the other way would be like using kitchen shears to give yourself a hair cut to save from going to the barber. Ya, it's possible... but is it the best way? nah.
#6
02-22-2019, 06:31 PM
I get it but I already bought an eBay shell/blank kit in order to fix a smashed plastic housing a few months ago, and the blades it came with are too fat to slide into the tumbler. Luckily the plastic part wasn’t as poorly copied. On top of that however, driving an hour and handing over $50 (or any amount of money for that matter) instead of swapping a couple plugs isn’t my style, and it doesn’t address the cluster issue either. I realize that some wouldn’t go this way, I just want to know if there’s anything I’m missing. I do appreciate the input though Llama.
#7
02-22-2019, 08:12 PM
Camel Trophy
If you have not already purchased the 03, I would pass and opt for either an earlier P38 4.6 or an earlier Disco 4.0 as those engines are better.
As far as the computer swaps, slabs and TCU computers have no effect on engine ECU or Body functions BCU. The inst cluster, ECU, BCU must be kept together to keep the mileage. The fob is connected to the BCU. The IDM is easily synced to either BCU.
You could either program FOB to work with non-matching BCU at shop or dealer, buy new fob from the UK, or program cluster to match non-matching BCU (but that would keep whichever mileage is lowest).
Based on your preference you can do what you want. Let us know if you have additional questions.
As far as the computer swaps, slabs and TCU computers have no effect on engine ECU or Body functions BCU. The inst cluster, ECU, BCU must be kept together to keep the mileage. The fob is connected to the BCU. The IDM is easily synced to either BCU.
You could either program FOB to work with non-matching BCU at shop or dealer, buy new fob from the UK, or program cluster to match non-matching BCU (but that would keep whichever mileage is lowest).
Based on your preference you can do what you want. Let us know if you have additional questions.
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shanechevelle (02-24-2019)
#8
02-22-2019, 11:02 PM
Ahhh. Ok, sounds like TCU and SLABS can stay! This is new info. To clarify, I have an 04 that a really good friend of mine (and an ex as it were) bought new as we were splitting up. I’ve always admired the truck and know for a fact it has led a pampered life. I’ve put almost 10,000 miles on this truck in the last year. It runs like a top, burns no oil, and has had 14 years of dealer maintenance thrown at it. Unfortunately keeping the frame in good nick wasn’t part of the service regimen and it’s not got much life left. I stumbled onto an 03 that is in perfect condition underneath and has $1,200 worth of Goodyears with about 100 miles on them, but suffered an oil pump problem. I plan to marry the engine from the pampered 04 to the chassis of the 03. The 03 also has a tan interior which I will yank out in favor of the black interior from the 04.
I read in the RAVE that the IDM syncs by itself after five minutes or something but I’m trying to eliminate as many variables as possible when I do the swap. Sure, I can have people program the fob, or the BCU/cluster or whatever, or I can buy as many parts from the UK as they’ll sell me. But, I have one truck that runs perfectly, has no codes, and everything save for the frame is tip top and works as the day it was new. She would have it no other way. I also just bought another truck with a bad engine, no remote locking capability and a hardware store key. Being the frugal chap that I am I would like to combine the two and reuse as much from the donor truck as is possible, while eliminating some of the aforementioned encumbrances. This is not an issue of trying to do it on the cheap as much as it’s about reuse, for the simple fact that I can. And I like to learn new things along the way. The interest of the post was to find out factual information about what is not possible or feasible when taking this approach. I hope this adds some clarity.
Thanks for the advice from everyone. I really do appreciate it and I’ll take it all.
I read in the RAVE that the IDM syncs by itself after five minutes or something but I’m trying to eliminate as many variables as possible when I do the swap. Sure, I can have people program the fob, or the BCU/cluster or whatever, or I can buy as many parts from the UK as they’ll sell me. But, I have one truck that runs perfectly, has no codes, and everything save for the frame is tip top and works as the day it was new. She would have it no other way. I also just bought another truck with a bad engine, no remote locking capability and a hardware store key. Being the frugal chap that I am I would like to combine the two and reuse as much from the donor truck as is possible, while eliminating some of the aforementioned encumbrances. This is not an issue of trying to do it on the cheap as much as it’s about reuse, for the simple fact that I can. And I like to learn new things along the way. The interest of the post was to find out factual information about what is not possible or feasible when taking this approach. I hope this adds some clarity.
Thanks for the advice from everyone. I really do appreciate it and I’ll take it all.
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