Overheating Again

I have a 2000 BMW 323i 5spd. No clutch fan, just the electric fan. I replaced the electric fan about 4 months ago. Last week my water pump went and caused my serpentine belt to break. I changed my water pump, thermostat, and belts. I had the car idling today and it ran hot. The only thing i could think was the fan not coming on. I turned the AC wide open and the electric fan did not kick on. Im sure the fan isnt bad after 4 months. Where do I start? The 50A fan fuse is good. ?????

Check you temp sensor in the lower hose. If you disconnect it when the ac is on, it should cause your fan to go into high speed.

There is no seperate relay. It is all contained in the fan controller attached to the fan itself.

Have you properly Bled the system?

I dont really notice my fan coming on too frequently, FWIW.

This is exactly why replacing the system as a whole is better, when one can afford it, as it keeps you from having to revisit the same job over and over...afterall thats what the VCG job is for.

Good Luck to you...try bleeding properly, DMAX has an alternate way to Bleed, which I happen to use...Search his screen name, and Bleeding cooling system.

+1 the only time i notice my fan coming on is when I get to the top of a hill climb of like 5 minutes of constant uphill acceleration

After you reinstalled your waterpump & thermostat.. did you remember to bleed the cooling system? If not, you will get overheating from trapped air pockets in the system.

So did you just take your clutch fan out and replace it with the electric fan, or did you just take out the clutch fan and leave only the aux fan?

^^ can't read

Originally Posted by WDE46

So did you just take your clutch fan out and replace it with the electric fan, or did you just take out the clutch fan and leave only the aux fan?

As I understand his car is manual, and only has an electronic fan.

Originally Posted by ///MPR77

As I understand his car is manual, and only has an electronic fan.

Yeah that just didn't click with me for some reason. He said 5 speed and for some reason i just thought 5 speed steptronic...

The fan is working!! Got it to operating temp tried the bleeding screw and nothing. Then a lot of steam by the thermostat. Then I loosened the bleed screw and steam started coming out. Then the damn bleed screw broke. My understanding is i keep messing with the bleed screw when the car is at operating temp till antifreeze comes out. ?? Now I just have to get the broke bleed screw out. Am I right?

My understanding, and experience, is that you bleed the system cold. I recently overhauled my cooling system and followed the Bentley manual procedure, which bleeds the system with a cool engine, ignition on (but engine off), temp set at highest setting and fan a lowest setting (but still on). You can hear the heater valve in the cooling system open. Then you open the bleed screw and fill the expansion tank until full.

Originally Posted by jlelectricllc

The fan is working!! Got it to operating temp tried the bleeding screw and nothing. Then a lot of steam by the thermostat. Then I loosened the bleed screw and steam started coming out. Then the damn bleed screw broke. My understanding is i keep messing with the bleed screw when the car is at operating temp till antifreeze comes out. ?? Now I just have to get the broke bleed screw out. Am I right?

I just completely take the bleed screw out, and let the water flow, it will make a mess, until that stream of water quits bubbling. Gently replace, and tighten the bleed screw, and turkey baste, or syphon excess coolant out of the expansion tank, and continue to monitor the level every day when engine is cold, you will likely be a little low a couple of times as you check it each day, but keep filling so that the float is flush with the filler rim, and you will be fine.

Thanks. I guess I left the gentle part of it out. Ill just have to buy another screw. Atleast it got narrowed to the bleeding. Thanks everyone for the help!

Originally Posted by jlelectricllc

Thanks. I guess I left the gentle part of it out. Ill just have to buy another screw. Atleast it got narrowed to the bleeding. Thanks everyone for the help!

No problem, best of luck to ya.

Park you car on an incline with the front end higher than the rear when bleeding it.

Originally Posted by BMWCaptain

Park you car on an incline with the front end higher than the rear when bleeding it.

...or put the front end on jack stands.

I drained the system. Put coolant in until it came out of the bleed screw. Turned on heat high with fan on 1. engine off. The coolant will not go down. I put about 1.5 gallons in and it wont go down anymore. Any suggestions. Almost like the thermostat isnt kicking in. Its new tho

Originally Posted by jlelectricllc

I drained the system. Put coolant in until it came out of the bleed screw. Turned on heat high with fan on 1. engine off. The coolant will not go down. I put about 1.5 gallons in and it wont go down anymore. Any suggestions. Almost like the thermostat isnt kicking in. Its new tho

You'll need to syphon or extract extraneous coolant... I use a turkey baster.

Originally Posted by jlelectricllc

I drained the system. Put coolant in until it came out of the bleed screw. Turned on heat high with fan on 1. engine off. The coolant will not go down. I put about 1.5 gallons in and it wont go down anymore. Any suggestions. Almost like the thermostat isnt kicking in. Its new tho

Is this the order you did it in? If so, things are a little off.
The heater should be on full hot (center console turned up as well) with the fan on the lowest setting with the ignition on, but engine not running.
Then you fill and bleed.

At this point you could run the engine until hot, and keep a close eye on the level in the ET.

Should I drain what I put in and start over? I know I dont have enough in there. I drained the block also when I change the pump. Only 1.5 gallons went in. I have had the heat on 91F and fan on low and the coolant will not go down. Start the car up and still wont go down. The plastic gets extremely hot around the bleed screw.

Ok, once you're confident the stream of coolant is bubble free, with heat on, car on (engine off) then it's just a matter of sucking the remaining coolant from your expansion tank...this is how the coolant will "go down"

It sounds like your over thinking it.


Like I said once you get that sorted out, check level every morning when engine is cold until you no longer have to top it off.