Hi folks--noobie here--been lurking a while. Tried searching for my answer in previous posts, and seemed to come close, but not quite, so here goes:

I have a 2002 Disco with the 4.0, which has Secondary Air Injection/SAI. Motor is toast, as prior owner ran her dry via blown tee fitting on upper radiator hose. It does still run, but sounds like its almost seized. Heads are probably still good.
Just picked up a crunched 2000 Disco with a good running 4.0, but it is a non-SAI motor. If I swap in the 2000 non-SAI motor into the 2002, what problems will I have? The 2000 motor just had the heads done, and the motor runs nicely, so I would hate to have to take them off, however, I want to do the repair properly and not stare at a MIL light for eternity because the ECU is looking to trigger the SAI components.

Questions:
1) If I swap the 2000 straight into the 2002, and not use any SAI components, will it run ok with the 2002 ECU? (Will it trigger a MIL code?)
2) Are the SAI system components I would need to swap over from the 2002 motor onto the 2000 motor strictly the items on the intake manifold and heads?
3) Can I use the 2000 ECU in the 2002 vehicle, with the 2000 motor, or are there other items tied to ECU that will get affected?

Thanks for your anticipated help.

 

Keep it legal and just put your SAI heads on the donor engine and all will be good.

 

You can drop in the non SAI engine and all will be good EXCEPT you will get a check engine light and you will not pass inspection if you have them.
You would need to swap your heads and all SAI components.
If you swapped the non SAI ECU too, no MIL, but again you would not pass emissions because your VIN is a SAI VIN#.
If you do not have emissions testing, swap engines and ECU's and alarm computers and all is well.
You may or may not have problems with the alarm and ECU syncing if you swap ECU's, it is pretty hit and mis on that.
The dealer can always sync them up too.

 

Best bet for you is going to be putting your heads on the new motor, this will invole the lease amount of work and you wont have to mess with the electronics.

 

You can not swap out the the ECU, unless you want to pay $100 plus to a dealer to reprogram it so it will communicate with the BCU, otherwise the engine won't start.
Just swap the heads and get on with driving it.

 

Thanks for the quick replies, guys. I figured I'd be swapping heads, but I wanted to be sure. Guess I'll be ordering a top side gasket set and head bolts later on tomorrow. First, need to yank the good one out tomorrow morning...fire up the coffee pot!
Thanks again.

 

So you swap the BCU too.
I'm not saying he should go that route, I'm just saying it can be done that way.

 

Swapping heads is the low tech way and will work.
My worry is that things may go wrong.

Advantage of swapping heads is new head gaskets - again.

disadvantage - messy messy business. And stress to bolt holes on engine deck.
What if there are helicores in there?
What if the head were shaved and there are shims to deal with?
What if the other motor was decked?
Manifold bolts will shear when loosened as they are old.
When I think of all the above, it give me pause.

Seems pulling two electronic boxes out and paying a dealer $100 is better to me.
And being RID of SAI for good - bonus.

Unless you are in California.
In Cali - do the SAI thing - if the rover was bought in California originally.

If brought into the State with SAI - you must keep it.
If brought in without SAI you are OK.

 

just swap the heads, while the motor is sitting on the floor. it will be the easiest LR head gasket replacement you will ever do.
how many miles are on the replacement motor?
you might want to replace the timing chain, oil pump and water pump while it out on the floor, and be done with it.

 

I wanted to point this out to him simply cause most people are not aware of the fact that you either install both the ECU and BCU from the same donor vehicle, so they can communicate when in the other vehicle or pay the big bucks to install just the BCU, tow it and have the dealer reprogram the replacement.