Thermostat
 

The shop is saying that my thermostat need replacing, this from their computer, no indication on the dash, living in S FL, I never noticed any malfunction, is this a huge $$ job, are they scamming me?, I no longer trust even the indie's after a few screwups that they have done...
Unfortunately I just can't do my own work anymore....gettin' too old...

I assume it failed in open position (if it's indeed failed) since you notice no malfunction. Is the temp needle in 12 o'clock position or does it go down to 11o'clock when you're on the hway? That's an indication of opened Tstat.

Check your local BMW club. Perhaps a member can assist. Or you can host a get together and thy topic will be thermostat replacement and you can provide food and beer.

I have helped many Lotus owners this way.

On our 4.8is, the tstat has a sensor. That sensor technically measures when the tstat fails. I know this because I had it happen. It was a ridiculously simple job on the 4.8.

That being said. Does your car take a really long time to warm up in the morning. That is also an indication of a failed Tstat.

I also question how these mechanics know you have a failed tstat. If there is no code for it, how did they come to this conclusion?

You need to do what tmv said.

BMW t'stats fail open, drive it for a few miles on the hwy after warming it up.

If the gauge doesn't get to 12 o'clock, it's time for a new one. No pun intended!

The car(truck?) seems to be operating 100%, warms up to needle straight up. It almost never sees the highway, as it's my wifes daily driver...

I recently had the same code; interestingly enough just before it happened I had noticed it was warming up a bit slower than normal.

I cleared it, and it hasn't happened since - since it fails "open" I am not particularly worried about it, and will probably just replace it during a planned job including coolant & water pump change as I get closer to 100,000 miles.

Seems a fairly easy job, dealer quoted an outrageous price though.

If it gets to normal operating temp in a short amount of time (5 to 10 mins) and gauge stays at 12 o'clock during hwy operation, the shop has no idea what they're talking about.

^^^ +1...

If it is as the OP says, I might do/have a good Indy shop do a coolant flush and fill, and give the cooling sys components a look.

It might be nothing or it might be 'something', and if it is the CEO's dd, I would rather have her trust the car and happy/content, than not. ;)

If the OP doesn't like/trust his current Indy, there are others to choose from, in his area.
GL, mD

Oh fyi. When my Tstat died. I had a check engine. Somehow forgot that you had nothing. Thats the check engine that made me buy a scanner. Yea i doubt your tstat is dead.