Vista, I'm tomorrow changing out both thermostats. No warranty tough. I've to pay myself.
I've exactly the same symptoms like you plus auxiliary heating taking long time to get the car warmed up. Last winter the process was much faster. I also recognize not hot but warm air is flaying out from the heating vents, even after pretty long drive.

The car gets relatively fast to 60 but next is barely getting 75. Rather stays at 70ish. This is with no question NO GOOD AT ALL.

On top of all the happy stories with changing thermostats here I can point a few more from a Polish forum. Most, if not all, guys are getting 90 with new thermostats.

We'll see how that works for me tomorrow. I'll definitely posts results.

 

Sounds like your symptoms are identical to mine.

I wonder how many other owners are driving around in ignorance of this because BMW chose not to fit a temperature gauge on the dash. :thumbsdown:

 

Sound like my problem too, on stationary gets about 98 degrees but on drive drops to 60.

I have the main thermostat and plan to change it tomorrow, but after reading this I will change them both. If someone is interested I can try to make some pictures and post it as kind of DIY. I can't promise, but I can try

 

I've not collected the car yet. Due to terrible weather condition the garage didn't revive the ordered water pump to be replaced as the preventive maintenance. The car has 130K. In my previous Bimer the pump died at 140K.

What I can report is that they've found the main thermostat broken. It stays open.

 

Pics would be good. It looks like both thermostats will need changing at least every few years in order to keep the car running at operating temperature.

 

They create air swirl allowing for a more efficient idle

 

After changing thermostats the engine warms up quick and maintains temp above 90. Mostly its 91-96.

 

Changed them on Saturday, first I decided to change only the EGR thermostat, because it was much easier and tested - but after 20 miles driving it was not more than 70 degrees, so I had to change main thermostat as well, easy job, but one of the thermostat bolts broke in middle, so I had to take the water pump out and take it of, when I had the pump out I decided to change it for new one. Job done, car is reaching the temperature within 10-15 minutes - city drive, on idle is holding 90 for 30 minutes without any problem.

Just I'm not sure about independent or auxiliary heater - do I have one? I had E39 530d and X5 3.0d before and both of them had an auxiliary
heater, but I can here any sound than I have one or there is something like that working. I saw somewhere on the forum there is an electric one? Does someone knows more about it?

If there is one, is it possible to switch it on before I enter the car? Like on timer? I have the option to switch something on, but it is blowing only cold air or my heater just doesn't work?

 

In order to check if you have an auxiliary heating fitted, go in I-Drive to Climate and next as per pic



If you see selector called Independent Heating then you have it.

 

Thanks for the feedback. I'm still getting stonewalled by my local dealer on this and can see it dragging on unless I change them myself or fund changing of them myself. Pretty disappointing from BMW really