Engine Cooling System problems of the 2001 BMW 325

I think I know why the car catches on fire since mine almost did and I troubleshot the problem. The alternator is not disconnected from the battery when the ignition key is turned off and the car is parked in the driveway. If the alternator ever overheats for any reason (such as the cooling vent comes loose), the pass transistor in the built in regulator of the alternator begins to short. Since it is never disconnected from the battery (even with the ignition key removed) the fist symptom appears to be a bad battery as the alternator kills the battery. Especially if you replace the battery with a new, fresh one and continue to drive the car the pass transistor continues to short more and more (it charges the battery more and more leading to overcharging and possible fire) and eventually shorts so bad that even when turned off it draws so much current from the battery that it starts to catch fire. If at this point you don't happen to be there to disconnect the battery it becomes a cascaded failure and will become an engine fire. I know because this is exactly what happened to me. I was lucky enough to catch it and figured it out by measuring the resistance of the alternator and was shocked at how low it was. I replaced the alternator and everything has been fine since. I still have the old alternator if anyone wants to examine it. In my opinion the alternator should never be left connected to the battery with the ignition key off. I just don't see any reason for it. Sincerely, kenneth a. Young.

Consumer states that while driving car would overheat. Engine fan fell off vehicle. Dealer notified.

The contact owns a 2001 BMW 325ci. The contact stated that she constantly experienced failure with the fan motor. The failure caused the electrical circuitry of the fan control unit to overload and fail, which caused the fan to stop operating. While driving approximately 70 mph, the vehicle began smoking along with a dramatic increase in temperature. The vehicle was towed to a local dealer and they stated that the engine failed and needed to be replaced. The vehicle has not been repaired because the failure is not covered under her warranty. The manufacturer did not assist. The failure mileage was 22,000 and current mileage was 82,000.

Dealer replaced first car and is now having the same problem with the coolant system. Car continues to overheat.

The car overheated and had to be towed. I was told on June 4th that BMW was aware of the problem and had isolated it to a specific batch of bad fans and that the replacement fan was from a good car. The replacemnet fan failed on July 4th at 711 miles. There is still no recall notice from BMW. If they and you are aware of the issue why is nothing being done? cars that can break down are a safety issue as well as an inconvenience. There is also a report in your database of a car fire on the same model car from the same problem. Do people have to die before action is taken? if this were an aircraft incidence they would be ground and corrected. I am interested in what the procedure is when there is a known defect in a car.

The vehicle has been taken to the dealer on three occasion for an overheating problem, the consumer is concerned that the repeated overheating of the engine could result in a fire.

While driving the temperature sensor flashes "-40 degrees. " the consumer contacted the dealer , who stated that sensor is located in the front under the bumper, and is often hit by debris that causes the sensor to malfunction. The dealer will fix the sensor at the owners expense. The consumer feels this is a design flaw.