After buying a well used 99 earlier in the year, I became addicted to these things. I was looking at cars to flip on Craigslist and came across a clean 03 with 146k on it for 1800, so that got the wheels turning. I love mine but it has over 300k miles, and lots of little issues that I realized all add up in terms of time and money. After tackling the three amigos, no power locks, water leaks into cabin, codes for purge valve and o2 sensors, etc, I would still be left with a car that has frame rot and will eventually die.

​​​​The new one is pretty clean, one small door ding, a bit of clear peel on the roof, and has the three amigos too, but everything besides one lock work. It has an OME 2" lift and a larger electric fan fitted, seems to run well. Headlights have some condensation so I will bake them and open them up, clean them out and reseal. Hoping I'm not getting into a mess with the 4.6. he's also giving me an extra set of wheels and tires etc. It has a bunch of new parts, new windshield etc. All in all I think it's a good deal and I'm excited. It's a big upgrade from the old one and I can only hope it'll be as reliable as mine has been (all I really care about is not getting stranded in a remote area)

I hear a lot of horror stories about the 4.6, are they really that bad? In the even that it kicks the bucket, can a normal 4.0 be easily swapped in its place? That is sort of my backup plan in my mind. It seems like most of the non running 03-04s that I see are due to engine failure

 

If you read up through the threads and really just some hardcore dedicated browsing, you will learn a lot about the 4.6. The reason most 4.6 2003/2004 are trashed is because of ignorance/lack of preventative maintenance and not making oneself familiar with the quirks and anomalies specific to this truck. You can learn a lot about the 03/04s just by reading people's signature. It's all about prevent maint and getting in front of all the mechanical problems and sensor malfunctions that will surely reek havoc and possibly create catastrophic damage if left to their own devices.

The problem swapping a 4.0 and 4.6 is that the 03-04 had secondary-air smog related equipment while most 4.0s do not, from what I understand. If you have smog regulations in your county or state, you will have problems with the engine swap.

 

Within a few weeks time, I'm basically facing the same questions as you. We bought a 03 two weeks ago that I have been doing deferred maintenance on (brakes, shocks, etc, etc). We'd looked at an 01 with a bad trans the week before, but it was a little to grungy for my wife. But, while I was at the junkyard getting rid of our van...I asked the dude running the place if he had any Discovery's. He did, so I walked out and got a few small items.

Well, I made the mistake of asking him how much the trans and driveshafts would be from the wreck...and with the quote...that got the wheels turning in my noggin. And since the 03's head gaskets had never been done, the plan developed. I bought the bad trans 01 from the lady for the price of scrap (originally, she wanted $1500.00), she'd just been through a divorce and wanted it gone, prefect.

So, now I'm pulling both motors, swapping the 4.0 into the 03 temporarily, until I'm done rebuilding its 4.6, since I want this one as dependable "as possible" for my wife. Then, once that's done...l'll be swapping them back. I'll buy the parts needed for the 01 from the junkyard and get it road worthy for myself or to sell.

Good luck, with your project.

Brian.

 

Thanks for the info guys. It seems like the previous owner maintains the vehicle well but is not a rover guy (he left it idling the whole time in the parking lot, while I cringed) but I'm sure he changes all the fluids etc regularly. Hopefully it will work out well. I am hoping to get some miles out of it, but worst case I can find one with a good motor and swap them for pretty cheap if I factor in selling off the parts on it to offset the cost. It definitely looks nice and aside from a code for the evap and bad cat it checks out. Not sure if the old spark plug non fouler spacing out the oxygen sensor will be able to trick the ecu into thinking the cats are present if I gut them, but I may try that (old bmw fix)

 

If your 4.6 has SAI and you want to use a 4.0L P38 engine without SAI you'll have to use the 4.6 heads. Which should be no problem since you'll probably want to install rebuilt heads on your swap anyway -- so just use the 4.6 heads. Only other problem you might run into with the 4.0 if it's a GEMS engine the crank position sensor mount won't accept the Bosch CPS, so you have to retrofit the block with part # EIQ100020 to use the three wire Bosch CPS.

 

Honestly, this is how I feel too. I wouldn't own a 4.6. Tons of liner, electrical and oil pressure issues on here. Thread after thread.....Of course, these forums only really talk about the bad, not neccessarilly the good, remember, people come here with there problems. So it's personal preference I guess..If you can get one cheap, then go for it.

 

Quick question Manbeer - why are you not a "Rover Guy" if you let your Disco idle?!

 

x2.....

 

Island Dave,
​​​​​​Perhaps I came off wrong, it was in reference to the large amount of threads that I have read re coolant temp and overheating issues where everyone seems to refer to excessive idling as abuse. Since reading these and using my OBD2 Reader to log Temps, I stopped idling more than a few minutes as if I went much beyond on a warm day I saw Temps climbing to 212ish before I shut down out of fear. I always see people mentioning Temps of 215+ as being potentially damaging to these engines so I just sort of assumed that it was a major no no.

Anyway I picked the car up last night, it's odd but I noticed that the steering is much lighter than on my 99, I'm not sure if it is because of something different in the design or something wrong either on my old one or the new one. All I can say is that I prefer the stiffer feel of my 99 and with their was a way to make the new one more like that. Also, I noticed that the power steering system is circulating in an almost violently strong manner. There is constant activity in the reservoir, fluid moving around at idle and splashing inside, and when I drive I hear it sloshing when I accelerate and turn. It's odd to me. I also found a coolant leak right on top of the thermostat that I will have to look into tomorrow

What's kind of funny too is that I hadn't realized it at first but there is no sunroof. Considering how badly my old one leaked I don't really mind, it's just that I've never seen one without before. It's also the base model I think, has pleather seats etc. I kind of like it though. Factory stereo sounds terrible compared to the HK, which I still wasn't crazy about...itll give me a good excuse to upgrade though. Just ordered a set of 265/75/16s from discount tire's eBay store for 310 after rebates so I'm pretty happy about that, now time to fix the three amigos and a few other things and I think this one is a keeper

 

Both our 03 and 01 have violent fluid action going on within the PS reservoir. It kind of surprised me, too. Never seen such a thing before (been a mechanic for 39 years), but both are exactly the same...almost looks as though they're boiling (but I know this is not the case). Just kind of weird in my opinion.

I've changed gears on my engine swap. Decided to just put a used trans, new-upgraded front drive shaft and used y-pipe on the 01, and have my wife drive this one while I go through the 03's later on.

Brian.