I have the same " -- " reading on my 3.0.
I'm also curios if I can get it to display the oil temp somehow.

I have the same "--" for oil temp reading in our E39 530i and I have been told that is due to no oil temp sensor in the car.

Not sure if the 4.4 has an oil temp. The 4.6 and 4.8 do...

@Junkcosmos. You do want your engine heating up faster and running hotter as you get a cleaner and more efficient engine. When spring comes around, then summer, keep monitoring the temps. You want them to stay the same all year.

:iagree: The Oil Temperature Gauge gets its Reading from the Oil Level - Oil Quality Sensor in the botom of the Oil Pan ( that was the case for my X5 4.8is, and i looked everywhere for The sensor that operated the gauge and got nowhere. It was'nt until i changed it out that my gauge read correctly again )

Looking at the info and chain of events I would hazard a guess that the electronically controlled coolant thermostat was stuck open.

the 3.0 engines do not have an oil temp sensor. and the electronically controlled thermostats are monitored for stuck conditions and will throw a check engine light, both for a thermostat fault and a rich mixture condition due to the long warm up time for the engine.
Those of you without an 'iS' model don't have the oil temp gauge, which is what's in question here. The coolant temperature is normal here, just the oil temp is low.

Sounds like your problem is fixed. My 4.6 never goes above 210 and I have the cooling fan removed most of the year. I have a friend with an M3 and his oil temp sits around the 170-180 area driving around town because of his oversized racing radiator and only ever gets to 210 when he is on the track (we did manage to get the oil temp to about 230 while in Death Valley with an ambient air temp of 118 last summer!).