525i overheating

[jterrell]

My 525i starts overheating after driving a few miles. If the heater is turned on, the temperature guage goes back close to the normal range.
I have installed a new aftermarket thermostat but it still does the same thing.
Has anyone had a similar problem and has a solution to share?

[cwsmith]

Check your cooling fan system or your body grounds.

[lvella]

I had an overheating problem on my 1992 525i. I had to change the water pump and the thermostate. The Pump impeller is a composite material which had failed in my case.

[jpohlman]

My 325 was the same way. The plastic impeller broke. The dealer replaced it with the new metal impeller water pump. Apparently the changeover to metal impellers happened at the beginning of 1996. They replaced the termostat as well. According to my dealer, the thermostat is different from normal thermostats. There is wax in it that regulates the operation.

cheers

[Seth4Man]

If your car is a 2001, it is likely that you still have the faulty fan. I worked at a BMW dealer while they were experiencing this problem. BMW had switched maufactures of the fans in order to save money. The fans, however, failed to come on when the cars needed them, and thus there was a substantial problem overheating. There was a factory recall of all 2001 BMWs, including the 525i, but if your dealer failed to notify you, there is no way you could know. If you take the car in, they will replace the fan and repair any other damage to the car at no cost to you. Good luck.

[rachel3790]

I have a 528I and it started overheating i replaced the waterpump the theremestate and it stilled overheated. I finally think i figured out what it's prob. is. There is something loose in the radiator. I have to get it flushed. It doesn't happen all the time. But if the thing in it is big enough it would. I figured it out when i took it someplace and they noticed that bottom of the radiator wasn't hot... which led them to figure out that the water wasn't getting all the way through it. Well i hope that helps.