Someone not on the forums has brought the notion to me, of a more reliable 4.6 engine from a P38 as a possible candidate for an engine swap into a D2. He went on to say that the P38 4.6 is not prone to have the engine tick and that it was slightly better engineered than the Discovery 2 variant. I did an advanced search on here and found nothing on this matter so Im hoping everyone can chime in. Was he bull****ting me or is there truth to this? How can the same Rover V8 4.6 engine perform better on another model? Would it trully be an ideal engine swap for a D2? What would it take to do the swap? Do both models use the same transfer case, transmission and ECU? Would I have to switch to the GEMS fuel injection system?

Thanks

PS: Ive heard horror stories about the P38, mostly electrical and air suspension related. NEVER heard or read anything about engine problems or even engine ticks for that matter.

 

It's true. Better quality control maybe. Or maybe land rover chose better engines for the p38. When it was being produced the 4.6 only went into range rovers, so they could pick better blocks maybe. According to a couple of guys at disco web the best choice would be a GEMS p38 4.6, but it's a little more work to swap.

 

people have done it and like Jafir said, Gems 4.6 is great. CPS is different though so you have to get a bit nifty with a welder and has to be done very well. Other than that it's very close to the same engine but far less issues.

 

There does seem to be fewer liner complaints about the P38 4.6's. I wouldn't get too hung up on the GEMS vs. Bosch thing. The blocks were the same. I had a late 1999 P38 (Bosch engine) and when I sold it with 125,000 miles on it the engine was smooth and silent. I wish my D2 sounded half as good. The general consensus seems to be that the '03 and '04 blocks were produced using worn out tooling and limited QC. Because the engines were to be discontinued once the LR3 was introduced, it seems that nobody cared what was being produced.


That being said, there are plenty of D2 4.6's with relatively high miles on them. Of course, the original engine in my truck had out-of-round cylinders and was replaced at 67,000 miles so I don't own one of those!

 

The GEMS engine is reputedly of superior quality. I think it's like all vehicle manufacturers, as time goes by they start paring down on everything to maintain their competition in the market and the customer takes the rubbish. Also many parts are 'outsourced' to who knows where around the world and the QC is often local, and spasmodic, and sometimes non existent. Typically, the Ford BDA block was manufactured in the UK and was generally OK and then they outsourced it to South Africa for casting and that's when the real problems started with casting porosity and misdrilled oilways and waterways.

 

So the 4.6 installed in the 1999 P38's sold early in the model year are better than those sold later? I doubt that. I would be willing to bet that the earlier the block, the better the tooling. The best approach would probably be to get a 4.0 out of an early P38 and then install the rods and crank from your 4.6. Keep in mind that any engine out of a P38 is likely to have many miles on it and will probably need a full rebuild. At that point, you should skip the rolling the dice thing and just get a block with tophat liners.

 

good to know. Once again it irrates me that more time was put into the Range Rover than the Discovery. Vehicle would have suffered much less bad rep if they installed P38 quality engines in the D2. Imagine that? D2's with reliable silent smooth running engines? Only problems is air suspension bladders go bad around 90K and 3 amigos! That would have changed everything. A more reliable D2 would have given way to a "Discovery 3" model in the US rather than a newly badged LR3!

Dont know what I will do yet about my engine. I assume I still have time left before I have to really worry about an engine rebuild or engine swap. Just was curious about the P38 engine. May just keep my engine and have it completely rebuilt and power washed and painted to look new again. Maybe have it painted light green or light grey so I can more easily spot any potential fluid leaks in the future thereafter. Harder to spot a leak on a black engine!

 

when you were up in Seward Alaska was it a government facility? did they do any testing on you? probes anything like that?

 

This is an interesting article about the LR V8 engines - make of it what you will:

JE Robison Service — the blog: All you ever wanted to know about . . Land Rover V8 Engine Failures

 

I read that blog post a while back. I believe I have a Cotts block in my truck.