Okay, finally got some progress to report.

Got a G.A.S DISA repair kit, glad the DISA in the bad engine was a BMW OE unit and the diaphragm was holding vacuum.

As others have noted the GAS kit is well made, very high quality. I went with a Viton o-ring, for a few cents more, why not:



The old DISA was just flopping around, the plastic socket of the flap was rounded out:



All done, probably took 30-45 minutes working slowly (and getting distracted by text messages):



Next up, I noticed the intake manifold had a plug and o-ring seal. It goes between the runners for cylinders 3-4. I guess the earlier cars (maybe < 03/'01) had intake temperature sensor that plugs in and this plug just seals up the port. I thought I'd replace the o-ring, who knows maybe it was compression set and leaking? Probably not, but now I have more confidence in it. The o-ring is cheap (8x3, PN: 13-62-1-743-299).

New one is 8mm ID x 3mm. The old one measured about 2.67-2.72 mm (variance due to elasticity of material and the Harbor Freight caliper; good enough for this application):



Good as new:



Ok... onto the meat and potatoes (engine extraction). I had to disconnect the fuel lines, took the opportunity to replace the fuel filter. Glad I did, the old one looks to be original - date stamped "13 04 04" - and the mfg date of the car is 04/04. Oh well, new filter, and even a new used engine to go with it.




Link to video of black fuel pouring out of filter. That's original for sure.

...

Back to prep for engine extraction. Disconnect the transmission selector cable:



Lots of road grime, will get a thorough cleaning before going back in.

Disconnect the other hoses, cables, brake lines and sensor.

Remove the exhaust. This thing is such a pain in the butt. One piece from header to exhaust tips, wth. I'm sure they saved a few bucks on nuts/bolts/gaskets. Pain in the butt. Good thing I had a couple extra jack stands to support the damned thing when unbolting. I really need to buy a lift. PB Blast on the header bolts/nuts for 30 minutes or so and it was relatively easy with a breaker bar. It's out:



No action shots of the engine being pulled out, too busy doing it to take photos. I enlisted the help of my mom to hold the AC condenser and AC compressor (I didn't want to have the system recharged as that would be extra $$) while I pulled the engine/trans/subframe/front suspension out in one unit. I used a Harbor Freight transmission jack under the transmission (seems appropriate) and a HF engine hoist to the front lift point. Just wheeled it out. I forgot to disconnect the headlight level sensor from the control arm... and the arm of the sensor broke... doh! . It is what it is.



...and it's out. Mom checking out our good work (gloves make her an official helper. lol):



This is a milestone. Lots of good feelings (even with the broken sensor).


Driver's side of the transmission. This will be cleaned and the transmission filter and fluid will be changed.



Engine bay will be cleaned - have to eliminate the remnants of the rats. Hoses will be replaced, and electrical connectors will be cleaned with Electromotive or similar type of spray.




The garage is full... I need to get these parts back on the car so I can park a car in here again:


While the wheels were off I took them to Costco and got a set of Michelin PS4S at the end of 2018 when they had a great deal (it was like buy 3 get 1 free), they're under the work table.