Engine/Transmission (1998.5 - 2002) 24v to 12v swap

[Moose]

I have been pondering swapping a 12v engine into my 01 and I need some input on changing things over.



First off, I have always wanted a 12v truck but I prefer the 24v interior. I tried to find a suitable 98 12v truck but in my area they all seem to be either torn up or made of gold. I found an 01 that was setup nicely and was planning on p-pumping it. After much research and thinking I have decided to just pull the whole 24v out and convert the truck over to a 12v. I have searched this subject on TDR, Comp D, Diesel Bombers, etc. and I think I have a pretty good handle on what all needs to be done. I couldnt find any threads specifically dealing with 01 trucks so I just want to make sure I have my info correct before I start sourcing parts and pulling bolts.



With the truck being an 01 I dont think I can just install a 98 12v engine harness and carry on like 98. 5s and 99s can so the sensors need to be delt with. The 24v ECM has to stay for gauges. I know I need to keep the cam sensor for the alternator and such and from my reading, I should be able to use the cam sensor adapter and cam gear for a 24v p-pump swap. Oil pressure and IAT sensors can be adapted to pipe thread fittings and possibly the coolant sensor. I am not sure what needs to be done with crank sensor; can I just install it in the 12v position with the tone ring on the dampner or do I even need to keep it? Vacuum and PS pumps should just bolt up to the 12v timing case. Hoses with need to be replaced with 12v ones. Throttle cables with need to be converted or adapted.



Am I incorrect on anything or missing something that will need to be delt with?

 

[BigPapa]

Here are a couple of threads on this. I would take special note of Jim Leonard's (Dieseldemon) posts in the first thread.

https://www.turbodieselregister.com...-valve-engine-to-a-24-valve-2001-transmission

https://www.turbodieselregister.com/forums/showthread.php?234844-12-valve-swap-into-2001-24-valve

There's also several threads on CompD, like you mentioned.

 

[LNaugle]

I personally would p-pump it... Have you checked out Innovative Diesels kit? I also think atleast 1 of the members here has pulled off what you are thinking so hold tight and maybe he will see this... Personally I think it is easier to put a cummins in the fords but thats because i've done a couple... .

 

[Moose]

@BigPapa - I read those threads and figured out a fair bit. I didn't know how much of that would apply to my project since I have a manual trans. Seems like most of my searches across the forums turned up swaps on early 24v's and/or auto trans trucks so I didnt know how important the APPS was. I am not that concerned with retaining cruise control if it will require a lot of extra work/parts to make that one function operable.

@LNaugle - I had wanted to p-pump it at first but honestly I like the way an actual 12v engine runs and sounds, and you just cant get that from a p-pumped 24v.

 

[BigPapa]

The manual transmission will make it much easier. The only concern then would be making your gauges, alternator, and A/C work. The shut-off solenoid wiring will be the same. You'll need the 12V motor mounts. I believe the upper radiator hose would be the 12V and the 24V lower should be the same as the 12V. The oil line for the vacuum pump is different. I don't know on the '01 if you will need just the cam sensor or if the '01 even has a crank sensor. Early 24V's had crank only and I believe late models had only cam.

Jim Leonard (Dieseldemon) is The Man on things like this.

 

[juskol18]

Moose did you ever finish this project? If so what did you find out?

 

[BigPapa]

I searched and searched for this thread before PM'ing you (I REALLY don't like the search engine here) but couldn't find it. Then I remembered his truck is an '01 that uses the cam sensor which is a totally different issue than we have with the crank sensor.

 

[juskol18]

I purchased a 1998 engine harness and plugged it in. Everything works exept the shutoff solenoid. It's not getting 12v that should pull it up. I traced everything down to find out that the main power wire that goes to the solenoid relay isn't connected in the fuse box I believe it's #38 on the engine inline connection to the fuse box. And #9 which should signal the relay to come on isn't connected. Can someone give me a pin out of a 1998 12v engine harness? And a 1999 24v fuse box/harness

 

[rschriek]

I purchased a 1998 engine harness and plugged it in. Everything works exept the shutoff solenoid. It's not getting 12v that should pull it up. I traced everything down to find out that the main power wire that goes to the solenoid relay isn't connected in the fuse box I believe it's #38 on the engine inline connection to the fuse box. And #9 which should signal the relay to come on isn't connected. Can someone give me a pin out of a 1998 12v engine harness? And a 1999 24v fuse box/harness

I'm converting my 01 24valve to a 12 valve curious what did you do? I bought the 98 12valve engine harness and computer and a used 12 valve. Parts are hard to find dont wanna be stuck searching for any speciality parts. thanks

 

[BigPapa]

There are multiple threads on here about this. The simplest way, basically, is to make the truck "think" the 12V is an '01 24V. This is possible except for the VP44. You will need to use ALL the 24V sensors which means you'll need thread adapters and you'll need to extend the wiring on a couple. Depending on the transmission you have you'll need to use the 24V APPS with a mount kit on the P-pump. You'll need to keep the 24V ECM.

Now, for the fun part, since the truck is an '01 you'll need to use the 24V cam senor in place of the timing pin with an adapter kit which means you'll need to swap the 24V cam and run an electric lift pump or put the 24V cam gear on the 12V cam.

 

[rschriek]

I thought just putting the 98 harness and computer were the easiest with the 6 spd. Already bought them read alot of threads everything is just real scetchy on info. Was gonna originally do what you were talking about but couldn't find the info or the parts when i tried searching. thanks for the reply

 

[BigPapa]

I have heard of people using a '98 wiring harness. It may be just that simple. I have no experience doing it that way. Won't hurt to try since you already have the harness.