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I tried to start this thread a couple of days ago as my first bimmerfest post, but it said something about awaiting moderator approval and hasn't appeared. Some of my thought process is posted in various replies to others on this board.

I'm a newbie to BMWs but no stranger to engine compartments. In a nutshell, our recently acquired 2004 BMW X5 (E53 chassis, N62 engine), which I'd hoped to borrow from my better half to use as a tow vehicle for ice racing this weekend, sprang a serious leak from the timing cover weep-hole and bottom of the timing cover. Assuming incorrectly it was the water pump (WP), I picked one up with an o-ring kit.

Disassembly was surprisingly easy. I only removed the top engine trim, MAF tube and fan assembly for access, and pulled the water pump without disturbing the crank pulley. Once off, however, I noticed bits of broken rubber from a tubing joint about 2" in from the WP mounting surface, which I've since learned is part of the infamous N62 Coolant Transfer Pipe. Closer inspection showed another joint, this one misaligned by a couple to few mm, about 4" in from the WP mounting surface.

After clearing out most of the broken rubber, I was able to insert a handy socket with 1.2" o.d. through both joints, but not a socket with 1.3" diameter. Thus, I picked up from the local Home Depot one piece of "1-1/4 x 36-inch Aluminum Round Tubing" (model 142-344, SKU 1000163850).

I cut off a 5.5" piece of the tube at about a 60 degree angle (decided some angle, whether 30, 45 or 60 would be important to clear the misaligned second internal joint by rotation). After light sanding around the first joint, the tube was ever so slightly too big in the o.d., so I used a 1-1/4" Milwaukee Hole saw (rated for aluminum) from the same Home Depot to quickly clean up the OEM i.d.

After a thorough cleaning (brake cleaner, de-greaser, bottle-cleaner - hush, I'll replace it, paper towels, etc.), I filled the slot where I'd removed the broken rubber with Permatex Ultra Black, coated the entire outer surface of the custom aluminum alloy sleeve with the same stuff, and then twisted it most of the way in (well past both the first and at least partially past the second misaligned joint). I then used that same 1.2" o.d. socket and a light mallet to tap it the rest of the way in until it no longer obstructed flow from the WP, which turned out to be about 1.2" past the WP mounting surface on my casting, and then I bevel-ported the edge of the tube for good measure.

I let it dry overnight, filled it today, and the problem is obviously solved. Since ice racing was cancelled (due to warm weather, an increasingly troublesome issue for ice thickness), I thought I'd post up before I forget it all. Hope it helps!
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