Roll-over switches are very common -- cut the ignition when the car is upsidedown to prevent fires. Notorious for being too sensitive on certain English sports cars, cutting the ignition if the driver's door was closed too hard.

Probably nothing in a diesel, though. The egine will run until the fuel runs out or it locks up from oil starvation -- I would guess several minutes for the fuel to run out with the tank on it's side or inverted.

I'd pull a main bearing and take a look before completely dismantling -- if the bearings are good, leave the bottom end alone. Once you pull the pistons, you might as well do the whole job since you will need new rings to put them back in.

Rebuild is EXPENSIVE on these engines, at least the turbo versions, anyway, and if there isn't anything serious wrong I'd personally leave well enough alone.

What happened to the other engine?

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!