Re: 535 Temp Gauge during a/c & stop & go (archive)

Looks like you have taken care of the cooling system components very well with almost everything replaced.From your descriptions,the increase in temp only happens during traffic and at the lights.Double check you fan clutch and I suggest that you bypass the aux fan resistor and bridge a hi gauge wire across it and let the aux fan run at hi speed.I did that to my car to have better cooling effect in traffic,not because I have o/heating problems.Your symptoms points to insufficient cooling at idle with a/c on.Plse let me know of the followup and outcome.

moots '90 520i

: Hi,

: We've had a spell of triple digit temps here in the SF Bay Area and my '91 535 is doing something curious that bothers me.

: Running the a/c with a couple of passengers, stopped at a light in stop & go driving, it doesn't take long for the temp gauge to start creeping up. Normal position without a/c is straight up, rock steady in all kinds of temps and conditions.

: I chicken out as the needle approaches the next mark on the gauge and turn off the a/c and within a minute the needle is back to center.

: Car has new thermostat/water pump/hoses/coolant. Fan clutch is fine, system is bled of all air. Aux fan comes on as soon as a/c is turned on (which Bentley corroborates), presumably in low speed mode. The only thing I haven't determined is whether the aux fan switches to high speed at a higher temp. Haven't checked the fan switch or resistor.

: Any ideas? Is this normal behavior and will the temp stabilize at a higher setting? Bothersome.

: Appreciate your input. Thanks in advance,
: Adnan

Follow Ups:

[ Follow Ups ] [ 5-series (E34) Message Board ] [ Msg. Board FAQ ]

Questions, comments, or problems, please visit the Roadfly help desk.