2002 Romeo Engine vs. 2003-05 - 4.6L v8

[MyExplorer03v8Lim]

Hi Explorers,

I have a 4.6L v8 Limited 2003 Explorer. I had a shop swap in what they told me was a 2004 mountaineer engine after mine seized at 155k. The replacement engine has 76k.

I have identified casting numbers on my engine that lead me to believe it was originally in a 01 or 02 explorer. The casting numbers on both left and right sides are:
RF-IL2E-6090-D22D

It's really hard to get any info on those numbers, but they show up on a few mustang forums. Apparently they're from PI romeo engines from 2001 and 2003 Explorers. This means the engine came from the factory with the aluminum coolant passage in the intake manifold, and the heads have slight differences.

So it would seem that my 2003 explorer has a 2001 or 2002 engine.

Just wondering if anyone can help identify any major differences between the 2001-2002 Romeo 4.6L engines, and the ones used in the 2003-2005 explorers?

One thing that jumps out at me is the DPFE bolted onto my engine seems to be disconnected, and one with a different shaped wiring connector is hooked up instead, held loosely in place by vacuum hoses.

 

[extra-medium]

The explorers used the same 4.6L from 2002-2005, and the only differences I know of was an electronic throttle body in 04-05. Ford still used the 5.0 up until 2001 in the explorer. The PI just means the head is performance improved vs NPI (non-performance improved.)

Also if both heads have the same casting number it is an early generation 4.6, most likely from a mid 90's mustang or crown vic. The same casting number meant that they produced the same head and one was built backwards to make it for the other side of the motor. If you have the end casting number of D24D on one side, that is a newer motor with the updated coolant flow design since having the same design on both sides of the motor would cause reverse cooling on one side causing cooling problems. Hope that makes sense.

 

[MyExplorer03v8Lim]

The PI just means the head is performance improved vs NPI (non-performance improved.)

Thanks for clarifying that. I wasn't exactly sure of the terminology. Performance Improved makes sense. My intake is the PI type.

Also if both heads have the same casting number it is an early generation 4.6, most likely from a mid 90's mustang or crown vic. The same casting number meant that they produced the same head and one was built backwards to make it for the other side of the motor. Having the same design on both sides of the motor would cause reverse cooling on one side causing cooling problems. Hope that makes sense.

My engine has the same numbers on both sides of the block, although the placement and size of the numbers is different. They're larger on the passenger side of the engine.
I've watched an intake replacement video for a 4.6 mustang, and the DPFE (name?) sensor location is identical to the one on my engine that's been bypassed.
It's my guess that the shop used a mustang block and kept my throttle and intake, does that make sense? How would you move forward to repair/ improve this explorer? There are problems with the way the engine runs, but I won't have a code reader until later in the week. I'll be attempting to do a smoke test to seek out any vacuum leaks.
Maybe I should look into joining a mutang forum, do you have any suggestions on a good one?

 

[imp]

@MyExplorer03v8Lim
DPFE sensor provides input to the PCM (computer) giving info regarding movement of the EGR (Exhaust Gas Recirculation) valve. EGR valve position is important because it's movement (or lack thereof) affects engine performance AND emissions, and the danged valves are known to get gunky and stick. Very early EFI had no DPFE sensing. IOW, a bad EGR valve on them could go undetected (with increased exhaust emissions) a long time. Now, that is detected and a code generated.

If you have the incorrect DPFE sensor, it may be the cause for your poor engine performance. imp

 

[MyExplorer03v8Lim]

@MyExplorer03v8Lim
DPFE sensor provides input to the PCM (computer) giving info regarding movement of the EGR (Exhaust Gas Recirculation) valve. EGR valve position is important because it's movement (or lack thereof) affects engine performance AND emissions, and the danged valves are known to get gunky and stick. Very early EFI had no DPFE sensing. IOW, a bad EGR valve on them could go undetected (with increased exhaust emissions) a long time. Now, that is detected and a code generated.

If you have the incorrect DPFE sensor, it may be the cause for your poor engine performance. imp

Thanks a lot for that detailed info. Upon further investigation I believe that I have the correct dpfe sensor installed on my engine.

The thing thats confusing to me is that there's another differently shaped dpfe sensor mounted to a bracket behind my throttle body area.

Maybe if I remove that sensor I can get some clues about the origin of my engine. Hmm. I wish I could find a vin on it somewhere.

 

[MyExplorer03v8Lim]

The explorers used the same 4.6L from 2002-2005, and the only differences I know of was an electronic throttle body in 04-05. Ford still used the 5.0 up until 2001 in the explorer. The PI just means the head is performance improved vs NPI (non-performance improved.)

Also if both heads have the same casting number it is an early generation 4.6, most likely from a mid 90's mustang or crown vic. The same casting number meant that they produced the same head and one was built backwards to make it for the other side of the motor. If you have the end casting number of D24D on one side, that is a newer motor with the updated coolant flow design since having the same design on both sides of the motor would cause reverse cooling on one side causing cooling problems. Hope that makes sense.

Do you happen to know where to look on the block for a VIN? I couldn't find one.

 

[extra-medium]

http://www.therangerstation.com/Magazine/Summer2010/Ford_4-6.htm

Have a little read. Too much to paraphrase.