View Full Version : No Heating in 1997 540I

03-07-2005, 10:39 PM

I got this major problem. The car is a 1997 540I and there is no heat at all when the car is at idle. This is killing me. However, when I rev the car up to 1500 rpm while standing still, I start to get some heat out of the vents. If I don't rev the car while waiting at a red light, the blowing air is dead Cold ... Once I am driving the car, the heat is back. No problem on highways...

Can this be the Water pump going weak ? The belt that drive the pump have been replaced not long ago.


03-08-2005, 06:05 PM
Does the tempature guage indicate normal, center, when the car is warmed up?

03-08-2005, 06:14 PM
The temperature indicate a normal operating temp (in the middle) in all situations.

03-08-2005, 07:02 PM
I'm not sure how E39's are, but in E34's we have a heater core, in which the coolant flows through to heat up air. On E34's this gets seized up, maybe you guys have the same problem?

03-08-2005, 09:14 PM
Your heater core may be restricted, do the coolant system flush it might help. If possible reverse flush the heater core (look to see what is coming out of it, sludge,...). This is the cheapest "repair" that you can perform on the cooling system. You may also have much biger problems.

P.S. Price on heater core (part only) is about $300 if I remember correctly.

03-14-2005, 09:41 AM
Someone told me (dealer) that it is 90% chance that the secondary water pump (V8 cars) is faulty. Does that sound normal to you ?

03-16-2005, 09:17 PM
Just check if auxilary water pump (electric) is working and you will know if they were right.

03-16-2005, 11:18 PM
And where is the auxiliary water pump ?