Heeeeeeeelp !!!!
Car is 1986 740T with B230 eng.
If I’m moving down the road, all is well.
Problem surfaces in stop and go traffic.
The more of it, the worse it gets.
In such situations, car starts to loose power,
and the rpms become unstable. Car stalls out if brake
is applied. I have to drive with my left foot on
the brake, and right trying to keep the rpms up.
If I pull over, and open the hood I can feel enormous
amount of generated heat which I think is the cause of
the problem. With the hood open for a while, rpms will
stabilize, and I can resume driving (hood closed) forever
and a day if the traffic is moving. If not, same thing happens.
Now for the tricky part… the temperature gauge always stays
close to the middle. There is no boil-over or loss of coolant.
I have no usual indication of cooling system problems.
I just feel something is definitely wrong. No car should generate
so much heat under the hood. Not even turbos.
I could easily roast a goat under there …
Water pump is 2 years old. Regular mechanical, and the front electric fans
are working. What should I do:

Install extra fan. If so how ?

Manually override the control of existing electric fan.
(If so how ?)

Install thermal switch that kicks in at lower temperature
(If so, where do I find one)

Find the component (electrical ???) that is failing and replace it
(Which are the most likely suspects ?)

Drive with the hood open or entirely removed

Push the car over cliff and report stolen

All opinions welcome !