Alright so Im looking for some input on the 4.6 engine as it was used in 2 different models. Notoriously the 4.6 was used in the 2003/4 Discovery 2 and in the P38 Range Rover. For some reason Ive NEVER heard anyone mention an engine tick or any other major problems with the engine in the P38. Yet in our D2's its all to common. What gives? How can the same engine be a POS in one model but better in another? So what are the differences between these two 4.6 engines and what about swapping over the 4.6 from a 2002 P38 into an 2004 Land Rover Discovery 2?

I'm anticipating a major engine rebuild or swap later THIS YEAR. Id like to get it done before ever it becomes a problem and get that off my chest..... Thinking about a couple different options.

1) rebuild my original engine from buttom up. I like this idea.
2.) Swap for a new updated 4.6 engine
3.) Throw in a 2002 P38 engine and do the head gaskets.

 

I'm not too sure, but all of the P38 4.6 motors I have seen are GEMS units while the D2 4.6 motors are Bosch.

Interested to hear if this is always the case.