When there is no access it's common to loosen the engine mounts and raise the engine with an engine hangar. People build them with framing lumber. You can make the lift point with a long eye bolt. You can get about a miracle inch of space you do have to be careful with the limited amount of lift.

I dont have access to that engine model to figure out a magic bullet option.

Can you get access sideways where a chisel and hammer can turn the nut/bolt by hitting the corner of the hex? If you can get it released you can maybe get it out with a socket by hand.

Another possibility: can you get a sawzall blade in there and cut through the bolt head? Recently I had a completely rounded bolt I had to cut it off flush to remove the part (shock absorber mount). The suck part was it was a washer head bolt so even through the bolt was like 8-9mm the part I had to cut through was more like 20mm!

Is there no path to somewhere you can get a ratchet even with multiple flex joints? When doing the rear wheel bearing, I used about 20" of extension and 2-3 flex joints to get the bolts loose without removing the CV axle.

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2011 E70 • N55 (me)
2012 E70 • N63 (wife)