I'm about to start an LS swap because my 2004 D2s block has cracked (plus the LS will be a big upgrade, imo), but have been procrastinating for fear of getting stuck mid swap, or having small things catch me up. I seem particularly concerned about tying in the exhaust system to the LS manifold (I don't/can't fabricate and exhaust folks around me [West GA] are very reluctant to touch a Rover).

I'd consider myself to be decently mechanical and have swapped out head gaskets on the D2 and a couple Hemis as well as a rear main seal. On my current 2004 D2, I've changed the head gaskets, full exhaust system (magnaflow), front ball joints (upper and lower), heavy duty drag link and tie rod, steering dampener, wheel hubs on all 4 corners, drive shafts and flex disc, headliner (removed fabric and painted with black plastidip), several door and window regulators, sunroof motor replaced and drain repaired and done a bit of bodywork (mostly vinyl wrapping and front bumper replacement). I've also had to repair portions of the engine harness that melted on the exhaust and have some general experience with wiring and soldering. I absolutely cannot and should not be welding though...

I've never pulled a block and that seems to be intimidating me (which I assume it should). I'm also hesitant to order one of the crate engines that I've picked out fearing I've picked the wrong one. I was looking for a little encouragement and support in getting started. I've relied on this forum for over 15 years now, since buying my first 1999 D2, but this repair will be my biggest by far. I have 2 months to complete the engine work which is when my loaner vehicle will need to be returned. I plan to use the truck for general use, occasional towing (a small travel trailer or utility trailer), and occasional off-roading.

I have $12k to spend, but would like to spend closer to $10k total. I highly prefer a reman motor, so any suggestions are welcome. A few options I've found so far:
https://www.jegs.com/i/ATK-Engines/059/DCTM/10002/-1
https://www.summitracing.com/parts/h...make/chevrolet
https://spprecision.com/products/lm7...gine-sale.html.

Any input would be appreciated. Also, if there is a shop that has done a swap in the Atlanta metro area, a recommendation would be welcome. The Shop still hasn't done one, so I'm a little reluctant to be their test case and have everything be open ended regarding cost and time.

 

You sound like you have enough experience to do the swap. The swap can be characterized as a bunch of smaller projects. There are some steps that it would be helpful to have a second set of hands to help. You should be able to complete the engine swap in two months taking your time, but the Disco being your main transportation may be an issue because you need to budget time in case of troubleshooting. The two month window may become tight if you run into unexpected roadblocks such as a backordered part.

Because of that, I would recommended extensively preordering and preplanning the entire swap (starting with the swap kit, which can be backordered for a while). That being said, it can be hard to predict what issues you may run into. To be honest, it may be a good idea to have a shop on speed-dial in case you get stuck. ACE can help you with phone support, and we can help you here, but that can only get you so far. ACE may have some other idea on other shops.

Looking over your engine options — I would not recommend any of these engines choices you have selected. Particularly, the first two have performance cams, which will not work well with the 4HP24 torque converter. You need to stick either with a stock cam or at most a stage 1 cam. Also, most long blocks don’t come with intakes, coils, and a bunch of little parts that will nickel and dime you. I think it best to get a used LM7/LM4 to use as a core to get all of those little parts. A local shop may be able to rebuild a core engine for a better price. For remanufactured engine options with factory parts you can look at Fraser or Tristar. I personally have had good luck with my used LM4, which I bought with a known mileage and history. I think that is the way to go, but I get wanting a ‘new’ engine.

Exhaust shops should not be concerned. The changes are straightforward and there is nothing particularly special about the exhaust setup.

 

Thanks, I appreciate the info and feedback. Glad I didn't blindly order one of those motors. I have all the other parts bookmarked and have been researching for a while now, aside from the motor. I just need to pull the trigger and get started at this point. The Fraser and Tristar reman'd long blocks look real good, but can understand how the price will really bump up when all of the additional parts have to be bought that would otherwise come with a used motor. I'll start looking at used motors on car-part right away. I'll post my second go at buying a motor here, taking your info into account, before making the purchase (if you don't mind). I don't have any experience shopping for motors, which is the main reason I figured I'd just get a crate motor; but I'll try to shop for a used one. Any tips when shopping for a used motor for the swap (mileage?)? I was going to look for motors from a 2003-2004 Envoy XL to start.

Knowing I'll have some support when I run into issues really puts my mind at rest. Thanks again...

 

Car-part is a great resource. The LM4 from the 2004 GMC Envoy XL is a great option. I feel like a lot of them were commuters and received regular maintenance. I would see what you get local in car-part results and then start calling junkyards based on the results. I'd make sure to call a few near you and see what you can find. The junkyards will have more information about the engines than is listed on Car-part. Some will know the mileage of the cars. If the mileage is low (like below 130k), you may want to ask if they give you the VIN of the vehicle (you may also be able to find on pictures on car-part). If they will give it to you (some may not), consider running a vehicle history report to see how regularly it was serviced.

Some places may be willing to negotiate a bit (especially the smaller places), so it may not hurt to tell them other parts you are looking for if you decide there is one engine you like. Make sure to also ask about core charges and see if they will waive the core charge. Make sure there is some sort of return policy. When you get the engine home, look inside - if there is anything strange, cut your losses, take it back, and find another. Chances are though, if you do your homework, it'll probably be good. Most LS engines, if cared for, last for a long time.

 

Todd should be back tomorrow but I did install the 150 amp alternator and installed my dual Flex a Lite fans all neatly connected to a GM fan harness and it all works well turning on at 205 on the primary and shutting off at 199.
The problem problem prompted me to also get a new group 27 Interstate battery and I'm now showing 14.3 volts at idle. Figured that should be sufficient. Also spaced the crank position bracket out away from the engine with one thin washer to perfectly center the ckps on the wheel. There is a slight bit of run out on the wheel but it stays centered mostly on the ckps. Unfortunately it still sets a code but not every time and the tach always works fine.
Next is to get a proper rover/jag code reader so I can see what the transmission is bitching about. Then I thought about another thing. During assembly of the engine in the engine bay I unpinned the CKPS to run the wires behind the bracketry down the front of the block and reinstalled the connector. Wonder if I got my wires backwards? Better look in the Rave I guess and see if the connector is shown. According to the pic I took of the plug connector before I re routed the plug my wires seem to be back where they came from. The reason I usually take pictures. I guess I could unplug and jumper the wires the other way and see what happens. Anyone know how a ckps acts when hooked backwards? We may find out. Lol. Self inflicted pain is not a good thing. Other than this little thing I am digging this truck. I want to get in it every time I need to go somewhere just to get a chance to drive it some more. My son and I plan on taking it camping on about a 1500 mile trip in a few weeks and I am really wanting to get it so I don't have to reset the Rover computer every time before I can drive it so I am going to double my efforts to figure this out. Will keep this updated.

One other thing is an occasional Knock sensor 2 circuit low code. I did install two new knock sensors and harness which were less than 100.00 from Advance Auto and maybe they are just pure junk. Maybe should've left the factory ones in there. Looks like the intake will be coming off soon!

 

Engine is almost ready to fire. I wanted to check my fuel lines for leaks so I went to turn the key, but not start the engine to prime the fuel system... No fuel in pressure!

I get fuel pressure if I jump the relay or ground the fuel pump trigger wire from the rover computer. I think that's a blue with pink wire.

The fuel gauge works

The gauges show a flashing "m" and "s" and "service engine soon" only.

The inertia switch doesn't seem tripped and I tried to jump it with no change.


I believe in the pump relay is a switched ground. What am I missing here? Maybe a rover computer ground or something else further up the chain for the relay trigger? Any help would be appreciated. I'm almost ready to start this thing and I'd hate for this to hold me up.

 

gm ECM send 12v to fuel pump relay and relay needs ground, Discovery ECM grounds relay and 12v is supplied from fusebox.

 

Is your LR crankshaft position sensor plugged in? Without it, no fuel pressure.

This is not how the ACE kit works for the fuel system. This way was tried and abandoned since it bypasses the inertia switch and because of other issues.

 

ok, I forgot it was just the ac engine swap not trans too.

 

Yes the rover crank sensor is plugged in. I suppose the next step is tracing the wires back and making sure they look good for that too. Everything else I've checked seems to be how it needs to be.

Yeah I was thinking about using the 12v+ signal from the gm pcm to switch a ground on a relay, but obviously that's a last resort.