cooling my 635

[pino85635csi]

Hi everyone I just joined , and I have a little problem, I have a 1985 635 csi , and I having a cooling issue, this last week it has started acting up , it usually is below half onthe gauge unless it the hot summer months 90+. but it hasnt nearly been that hot around here about 60 degrees. I have had the clutch fan replaced 4 months ago when I had a similar problem and it was fine until this week , it was at about 3/4 way up on the gauge . I was hoping to get some ideas , this is my first BMW .
thanks for any help
Pino

[ugly kid jon]

replace the thermostat and the antifreeze,

[1 slick 6]

The m30 big 6 in your car and other models of bmw likes to run on the warm side for some reason and during warm weather with the a/c on the needle on the temp gauge can creep up to 3/4 of the way. Believe it or not this is considered normal!

Not to worry, you can do what I and several other 6 series owners have done. On the upper radiator on the right/passenger side you will find 2 fan switches. The switches turn on your auxiliary cooling fan when the coolant reaches a certain temp and the cars mechanical fan isn't able to cool sufficiently alone.

One of these switches activates the low speed circuit of the fan at 91 degree C(196F). The high temp switch activates the high speed fan circuit at 99C/210F. Remove these switches and put low temp switch where the high temp switch was which will now activate your high speed circuit 91C/196F and replace the low speed switch with an 82C/180F switch available from Bavarian Autosport or BMP Design. The switch costs about 15 bucks and this will definitely make your car run cooler.

You can go one better if you like and in addition to the switches replace your thermostat which is an 80C/176F unit with either a 75C/167F unit or even a 71C/160F unit (the route I chose) and your car will run really cool. This shouldn't pose a problem with the fuel injection as the car goes into "closed loop" operation at about 30C/86F.

By the way, on the new low temp switch, you may have to file down the prongs to get it to fit on your vehicles connectors. Not a big deal. Hope this helps.