It could be electrical. The other potential problem is the radiator fan. They don't like thrashing around in water and you can easily shear off the blades. However, all those problems are nothing compared to bent or broken conrods or a damaged crankshaft.

Conrod/Crankshaft issues are, presumably, possible outcomes of water getting sucked in. I wonder if anyone makes a snorkel for the X...?

In any case, I'll be taking it slow and only after I've had a wade through.

Yep. Water doesn't compress like air. A mate of my ingested water into his brand new 5.7-litre V8 Jeep Grand Cherokee and one of the conrods broke and punched a hole through the crankcase... Ouch!

I haven't seen any snorkels for an E53.

Very ouch indeed.

I was only joking about the snorkel, I'm sure there is a raft of other things that would not really like to be under water either.

I've had to drive through deep water in most vehicles I've owned (hurricanes/tropical storms = street flooding) On my E36 I just removed the dinan intake tube that had the filter at the ground and put the filter straight on the MAF for the slow ride home in the deep water. As long as the water is below the intake you should be good, just keep the RPMs low to avoid physical damage if the water does get too high.

G'day mate, how did you go?

well just to update you guys, AAMI, wrote the car off.
didn't even contemplate fixing it.

No water got into the cabin of the car at all.

I guess they didn't want to take the chance of repairing it and then continue to go back and back for repairs.

Maybe there are so many electrics under the bonnet, it wasn't worth taking the chance of just replacing the engine.

they are replacing it with a brand new 2010 320i inc innovations etc..

There's probably good salvage value in it, presuming all the panels are straight and the interior, as you say, is okay. Even if only the engine was stuffed through hydraulic damage it's probably easier for them to write it off then to repair it.

Happy to be going to a 320i?

perhaps there is good salvage in it for them. Again the car was dead straight and clean.

My original car was a 320i, so its like for like.
but this one look much more classy.

the previous was that bmw bluw with grey leather, leather carpets etc.

this one is black with oyster leather, black mats, etc..

All good, thanks for asking. The water was only about knee deep, and, as it turned out, the capsite was all full so we ended up down the road where there was a bridge over the river. At least I can say i crossed the Goulburn river 4 times though!