D6N. ALY01509 What do I have leaking on the high pressure oil pump? That plug is right below this line going to the head.
It's hard to see from your photos but is that plug not part of the fuel transfer pump.? The pump will be lubricated by oil from the HEUI pump, or at the very least I think that the cavity between the two pumps will have oil in it. Ignore the fact that it is shown as a hexagon head in the illustration, but is it the plug I have circled below.? Bad news is that I can't find any piece parts for the fuel transfer pump, including the O-Ring under that plug, listed anywhere.
Nevermind, it is the side of the fuel pump.
So, we are pretty sure it's the weep hole? How technical is swapping this fuel transfer pump?
2 bolts plus fuel lines I think. The image is not very detailed.
Using the elbow fitting in the top LH corner your of your photo as orientation it gives the impression that the hole is located on the flat face on the bottom side of the fuel transfer pump as indicated by the arrow. That would make sense if it was a weep hole.
So, the main question is, if it's leaking oil from this weephole, is the transfer pump faulty, or the HPOP?
I dunno. That’s a question for someone more knowledgeable than me with this particular engine model.
Anyone else have any experience on this? Engine is a 3126 with HEUI. I ordered a new HPOP/transfer pump today. Internet research claims that when the seals in the HPOP start to fail, the oil leaks out the weephole instead of pushing into the fuel system.