So the popular wisdom seems to be that once a 5.0 V8 has overheated or has a head gasket leak, it's all over for that engine. Merely replacing the head gasket is not going to repair the engine, and from what I've seen and read, I would agree. It's going take more than that.
My research indicates that the engine is going to require some work, obviously. To do it properly it will have to come out. LR says it's a body off juob, but the guys at the Grand Rapids JLR dealer don't pull the body to swap motors so it's possible. Probably not fun, but possible.
So, plan on stripping the block and heads, taking them to a machine shop and have them all decked to flat. The parts reportedly warp, which makes a simple HG swap futile.
Plan on having the threads in the block for the head bolts reinfoced with inserts. Reports are that another side effect of the overheat is to warp the threads and they don't hold the bolts proerly, aloowing them to strip the threads. I had this happen to me on a D2, did that final 90 degree torque and I could feel the threads let go. Had to take that head off and helicoil the block., So, all threads get helicoiled or equvialent.
Might as well do a timing set while in there, check the usual stuff like bearings, rings, and the like.
Sure it might be expensive, but cheaper than a dodgy junkyard motor and certainly less than a reman.
And considering that I am seeing otherwise nice LR4's on the matrket for $2K, and assuming I have something to drive while all this is gertting done, this should yield a nice and cheapish LR4. Also this assumes that it's a head gasket problem and not a timing chain let go, that's a whole other disaster.

 

There are some cheap lr4s that run. I'm tempted to get one for one I can beat up.

 

Coincidentally, this head bolt issue is paramount in the diesels.
On all other aspects I must agree. Throwing the dice at a used engine, in which you may need to perform all this work anyways is troubling.
JLR does sell remanufactured engines. They do come with a warranty. But $$$.

 

I wouldn't get one that didn't run at all, that's kind of a sign of a timing chain issue.
There was a FBM listing for a LR4 kind of near me, $2K, would overheat after running for a short while, classic head gasket kind of problem, which is what my plans would address.
But if you wanted a cheapo to thrash, maybe a can of miracle head gasket miracle mix might keep it going for playing on the trail. I'm looking for an upgrade for the LR3. LR4's drive awfully nice.

 

Actually, $2k, the electronics are good but the engine is toast, is not a bad situation.
But if anything electronic is gone…

 

Listen, the engine is not a major issue as long as you are willing to go in and sort it out. The fact is aluminum engines with coolant problems and small diameter head bolts results in a warped head. The challenge is if you are willing to put in the time and the small fortune for tools and parts it can be fixed better than new. I would first say trying getting the vehicle for as cheap as you can and with as low mileage as you can. This should give you your best value. Then prepare to remove both heads. Once the heads are off you will need to resurface them flat. This can by done by a machine shop or with a very flat sanding block. Search youtube on how to do it at home. Also flatten the engine surface as well. You will want to make sure both surfaces are super flat,, .001 flat if you get my drift. Next use Huhn inserts. These are steel inserts to provide a superior anchor for the head bolts versus aluminum. The kits are not cheap but it is exactly what is needed. The solution allows you to upgrade to the large size bolts that came in the later models. Next since you have the heads off, freshen them up by checking all valves and replacing any that are beyond specs. Check the cams and cam cradle to make sure it is also straight and not warped. Clean out the cylinders as best you can and apply a light coat of assembly grease. Make sure you get all new chains and guides since you are this far in and do a deep cleaning of the VVT sprockets. Once you are done make sure you take your time re-assembling the engine. Timing is dependent on how you put it back together. Then make sure you freshen up all your coolant parts. I suggest metal aftermarket parts where possible. They do make a metal rear crossover now. Last make sure you fill the coolant system correctly and take further steps to alert and avoid overheating the engine. I am going to add some permanent gauges just to monitor the coolant temp and oil pressure. In the end this engine will be much tighter and hopefully way more reliable. Good luck.

 

that is an excellent cookbook level write up, thank you for taking the time to write that up!
So when one gets into the engine that far, is it worth checking the state of the bearings and rings? Or do they fold up pretty well?
I figured it was gioing to be expensive but cheaper than a reman and cheaper than buying another LR4 in better shape? The rest of the LR4 seems to hold up very nicely.

 

Since I am doing all this with the engine in, I am going to take a bit of a gamble on the rings and bearings. I am going to inspect the pistons tops and height to make sure the rods are still within specs and the cylinder walls for scoring or grooves. It turns over without labor but I will pull it through just to check for any binding. If all seems good I will button it back up. I plan on doing an oil change pretty quickly after I get it running to clean it out and check for metal chips. Also, I am addinga magnetic oil drain plug to help keep it clean.

 

LAND ROVER/RANGE ROVER/JAGUAR HEAD BOLT THREAD REPAIR — NS300L™ PROFESSIONAL UNIVERSAL THREAD REPAIR SYSTEM SPECIALIZING IN HEAD BOLT THREAD REPAIRTOYOTA HEAD BOLT THREAD REPAIR KIT LAND ROVER/RANGE ROVER/JAGUAR HYUNDAI KIA 3.3/3.5/3.8L HEAD BOLT THREAD REPAIR KIT (huhnsolutions.com)

For what these are, I don't think the price is too far out there. Will access to the holes be an issue with the engine still in the Rover?

 

Just the holes in the back but it has been done on this forum a couple times. The best solution I heard was unbolt the engine mount and jack up the engine for better clearance. Plus how you attach the drill requires a bit of ingenuity. I should have the heads off in the next day or two and will take pictures and walk my efforts through each side.