E34 525i M20 - Overheating only during standstill on a hot day

["Eugene Hoe" <eugene@xxxxxxxxxxx>]

My E34 525i M20 seems to ocasionally overheat when the car is at a
standstill or stuck in a traffic jam
on a hot day. When the car is moving, its absolutely fine. The temperature
gauge can reach as high as
3/4 way to the red spot on the temperature gauge.

The last time I checked the high speed fan mode on the aux fan by manual
bypassing it, it was working fine but noticed
it didn't activate even though the temperature reached 3/4 on the gauge. So
checked the radiator and found that
the bottom of the radiator was extremely hot whilst the upper portion of the
radiator was not as hot and since
the temperator sensor to activate the high speed fan was located at the
upper portion of the radiator, it didn't
activate the high speed fan. So the conslusion was the radiator was blocked
so had an entirely new radiator
put in several months back. Now the car operates much cooler when moving but
at standstill the temp can
still go up past half way point on the temp gauge.

Anyone got any ideas what else could be causing the overheating during
standstill?. The logical reasoning would
be the aux fan or the fan clutch but had those checked and both the fan
clutch and aux fan is working fine. I was also
told the aux fan should not kick into high speed mode during normal
operation, it only kicks in when the temp is really
high like past 3/4 mark on the temp gauge. Can anyone verify this?.

Any ideas appreciated....

------------------------------

End of bmw-digest V9 #2391
**************************