So started my car up Friday night. After about 5 seconds, bong, message on the dash saying "Stop! Low engine oil pressure".

Turned it off, walked away swearing, and cracked open a bottle of red.

So, I'm going to guess that I'm not so lucky that it's a sensor glitch. Oil is on max on the dipstick. 156k miles.

Anyone killed a TD6 engine before? 2004 Vogue TD6 - Remapped
2008 Porsche Cayenne S
1998 Lotus Elise

Sensors are not averse from failing. I had one incidence on a brand new vehivle of a sensor failure not many years ago. If you've the facility to do so, check the pressure with a guage, otherwise find and fit a replacement sensor and see if the problem persists before going into panic mode

I'd agree - especially this time of year - DAF HGV's are particularly prone to this & I often get back to the RDC with a dashboard lit up like a Christmas tree after manually checking.

A sensor change could very well be a cheap fix. 2003 Range Rover Vogue TD6

Just to follow up on this.

I did some research on the BMW forums, as the M57 engine has been used in a gazillion BMWs so there is more information there.

General consensus is that it's pretty hard to kill an M57. What can happen is an issue with the oil pump, whereby some of the bolts work loose causing the pump to leak back into the sump. Another issue is that the 2 little O rings on the central spigot of the oil filter housing can allow oil to bypass back to the sump.

So I figured there was no harm in taking a punt on the (cheap) basics first. First off, went to the local BMW dealer and got replacement O rings for the oil filter housing, then round to Euro Car Parts for a Mahle oil filter, an oil pressure sensor and 10 litres of their finest oil.

Spent an hour draining down the oil, replacing the O rings, filter, sensor and oil. While I was in the mood, also replaced the leaking EGR thermostat. Fired it up again and all is well. Done a hundred miles and still all is well (and added bonus, the coolant remains in the engine)  2004 Vogue TD6 - Remapped
2008 Porsche Cayenne S
1998 Lotus Elise