Just went and picked it up. For the entire 45 minute highway run, it was just above the blue. We get into town which is total of about 2 miles from the highway to parking garage and it started warming up. I was kind of hitting the manhole covers to purposely give it a few jolts to see if it would spring back to life. We get to the spot in the garage and the needle is at 12 o clock. I figured, maybe it's just stuck shut now. I drove around the garage in 1st gear for about 3 minutes and the needle never moved. I was at about 2-3k RPM the entire time.

Can I say the thermo is now unstuck? Not sure. Maybe it's just temporary. I think maybe the reason it got stuck in the first place is since my coolant was low for a few weeks, it may have gunked up. Now that there is fluid hitting it, since I added the water yesterday, it may have freed up.

Any insight on this?

is it a 3.0i?

to know if the thermostat is open or closed, and to know the real temperature, you have to open the hood and get your hands dirty a little:

The hose that goes into the top of the plastic expension tank starts to heat first. the hose on the other side of the radiator that goes down from the thermostat to the buttom of the radiator should be cold at this point. keep the car idling, and the temperature should start to climb: it should reach a point where you can barely touch the top hose, while the other one is still cold. if the top hose remains "touchable", i mean not so hot, then your thermostat is stuck open.

When you replace it, you will notice that it will be extremely hot and at one point, when the needle reads 12:00, the lower hose will suddenly become almost as hot as well (the thermostat will open). until you get this behavior, you have something wrong with the thermostat.

Yes it is a 3.0.

Thanks for the tip.

I am having the same issue what was your outcome??
 

OK nice to see the same issue out there. I have a 2002 X5 3.0 and my issue is that the needle out of the blue will go all the way red but the car does not seem to get hot?

It takes the car almost 25 min to get to 12:00 on the temp guage

My heat seems to be ok

Now my car is stalling when it's cold in reverse or drive

But once it warms up it's fine and the rpm's don't drop below 500 rpms

Could a bad therm cause the car to drop rpms when it's cold ??

Thanks

The best way to monitor your coolant temp is through the obc test modes (test 7) and watch the numbers. It should run up to about 78c then the thermostat opens. Shouldn't take more than several minutes, even in cold outside temps. My thermostat is on its way out and is sometimes sticking open and car stays at 66c rather than the quick run to 78c. But sometimes it functions perfectly. Sounds like you are experiencing similar behavior. Peak code confirms all this. Wish I could just find a DIY thread somewhere for a N62 thermostat replacement!!