What I have found out is that the coolant temperature gauge is not very accurate or I would say misleading. It may be that BMW had to do it this way because of the design of their cooling system.

If they didn't do it this way, they would be getting other complaints from a coolant temp gauge that one would think is possessed. I haven't checked V8 engines but usually when BMW(Germans) do one thing that works, they will do for all their systems, has been my experience. As for the 6 cyl. inline gauge this is the case.If this is something for you that is hard to believe, check it out for your self.

Those with OBDII systems(1996 and later) it will be much easier, those with 1995 and eariler it can still be done,just not as easy.

Ok, ready to hear,Im sure you are with all my prior rambling.

With a proper functioning cooling system, most will say their coolant gauge needles goes to about half way on gauge and stops. At the point that it 1st. stops, the temperature is around 160 deg.F.

Thats ok, most systems are fully warm at between 190-200 deg.F.and in a perfect world that would be great. Unfortunately parts wear, things plug up, its summer time in Texas and the coolant temperature rises be on that.Oh but wait, my gauge is still in the same place, how could it be to hot?????

Here's the part that's no good, the gauge doesn't start moving again until 225-230 deg.F. Under those prolonged conditions is why BMW cooling system don't survive. Even before that 225-230 deg. mark, running constant anywhere above 210 deg.F for any amount of time is putting a huge burden on that aluminum,plastic and rubber filled cooling system of parts. So whats the answer ?????

One needs to monitor their system. If you can be aware at where the temperature is and how long it's there, you can head off an expensive repair. You will need to install a coolant temperature gauge.

If anyone has any questions,concerns or even challenges,would be glad to hear from you.

Greg Donsbach, [email protected], BMW CCA Number: 489784