Please Help! Car overheats, No Heat

Hello

I am new to this forum. I have searched this forum but cannot seem to come up with an answer. I have a 2000 BMW 323Ci 5 speed with about 90k miles. I was driving the other day and my car began to overheat. I let the car cool down and got it home after having to stop a few times. I have no heat at all, the fan isnt kickin on, and the thermostat isnt opening. I have replaced the water pump about 1500 miles ago, i replaced the thermostat yesterday and have flushed the coolant and bleeded the system multiple times. Also my service engine light is not on. I cannot come up with an answer. Any advice is greatly appreciated. I do not want to have to take it to the dealer.

Thank You,

Don

Sounds like you got a bad thermostat

Don,

Are you sure that your thermostat isn't opening? How did you tell? Anyway, Here are a list of things I would check:

- Make absolutely sure that you have enough coolant in the system. When filling the coolant make sure that the bleeder screw is open and that the key is in position two with the heater at 91 and the fan setting at the lowest position.

- Check to see if the lower radiator hose is getting hot. There is a sensor on that hose that can go bad. It tells the aux fan to turn on.

- Check the fuses to make sure that the fuse for the Aux Fan isn't blown.

- Is there any dirt in between the radiator and the evaporator?

- Make sure there are no leaks. The o-rings in the hoses of the cooling system can get worn creating a leak which will deplete your coolant.

- Have you installed the drive belt correctly?


How long does it take before it overheats? Hope this helps...

Originally Posted by eurodriver

Don,

Are you sure that your thermostat isn't opening? How did you tell? Anyway, Here are a list of things I would check:

- Make absolutely sure that you have enough coolant in the system. When filling the coolant make sure that the bleeder screw is open and that the key is in position two with the heater at 91 and the fan setting at the lowest position.

- Check to see if the lower radiator hose is getting hot. There is a sensor on that hose that can go bad. It tells the aux fan to turn on.

- Check the fuses to make sure that the fuse for the Aux Fan isn't blown.

- Is there any dirt in between the radiator and the evaporator?

- Make sure there are no leaks. The o-rings in the hoses of the cooling system can get worn creating a leak which will deplete your coolant.

- Have you installed the drive belt correctly?


How long does it take before it overheats? Hope this helps...

+1. This sounds like a complete check. Very good.

Sounds similar to what happens when there is air in the coolant system.

An easy way to check for this is just turn the climate control to the max temperature (car is on accessory setting, do not crank engine), undo the bleeder screw, and than pour in coolant until it flows out of the bleeder screw.

A broken thermostat usually means a car that takes forever to heat up or overheats but the climate control still works.

And yeah, eurodriver's list looks really good, so that I would recommend that.

Well i went out today and messed with the car. The car is still overheating, I have no heat, and the fan is not coming on. I topped off the antifreeze the way that you had meantioned above and I have bled the system. There is no air in the system. The top hose is pressurized and hot. The lower hose is pressurized but is ice cold. When I replaced the water pump I did replace it with a advance auto parts one so I am wondering If maybe this pump has went up already

Originally Posted by 00bimmer323

The lower hose is pressurized but is ice cold. When I replaced the water pump I did replace it with a advance auto parts one so I am wondering If maybe this pump has went up already

those 2 things sound like a problem. as eurodriver said, the lower radiator hose should be getting hot.

Thanks to all that replied. I took the waterpump off today and the impeller had spun right off of the shaft. I replaced the water pump and now the car does not overheat and I have heat. Thanks again for the help

Originally Posted by 00bimmer323

Thanks to all that replied. I took the waterpump off today and the impeller had spun right off of the shaft. I replaced the water pump and now the car does not overheat and I have heat. Thanks again for the help

Congrats on isolating and fixing the problem. Just curious but did you replace the waterpump with another Advanced Auto waterpump? If so, I hope it lasts longer than the other one. With something like the waterpump you probably want to go with OEM to be on the safer side. I currently have Graf waterpump and I haven't had any problems with it and it's been a year and a half...

Originally Posted by Chris C

Congrats on isolating and fixing the problem. Just curious but did you replace the waterpump with another Advanced Auto waterpump? If so, I hope it lasts longer than the other one. With something like the waterpump you probably want to go with OEM to be on the safer side. I currently have Graf waterpump and I haven't had any problems with it and it's been a year and a half...

+1

Stick w/ OEM.