2006 330xi radiator fan coming on after cold start

gfuller40 · 05-30-2014, 04:52 PM

Hello -

I recently purchased a 2006 bmw 330xi with 100k miles on it. Lately when I start it in the morning, the fan will come on and run almost full blast. This happens anywhere from 30 seconds to a minute or two after starting the car. If I shut it down and immediately start it again, it goes away for whatever duration of the drive I have.

Some other observations I've had:

If I drive it while the fan is going nuts, it will either shut off on it's own or throw an over heat warning (10 minutes after driving) - shut it down, start back up and it's fine.

It only seems to happen once a day, not every time I start it. For instance, it will be fine in the morning, go to start it at lunch and the fan comes on, restart and it's fine.

I've replaced the lower radiator hose temp sensor - no luck.

I've heard it could be the water pump but I've yet to see any instance where someone has had these very same symptoms. Why would the fan come on a minute after starting the car while it's very cold?

I did check the temp when I got an overheat the second time it happened - reading was 115c (via odb)

There is another temp sensor by the oil filter but I'm going to hold off on replacing until I get some kind of feedback.

No CEL

Thanks!

deeLow · 05-30-2014, 05:39 PM

No CEL but it is possible you have shadow codes that are viewable with diag software like INPA.

After you restart, you can drive the car fine for XX amount of miles without an overheat warning?

gfuller40 · 05-30-2014, 06:08 PM

That is correct, After I restart I have yet to have the fan come back on, it's only at startup.

El Cheapo Loco · 05-30-2014, 06:56 PM

I had the same symptoms for a couple months before the water pump went at around 90k. So I'm willing to bet yours is the water pump as well. If your water pump has never been replaced at 100k, it's already running on borrowed time. Replace it now before you get stranded somewhere.

gfuller40 · 05-30-2014, 08:33 PM

After restarting, did the fan turn off? I just don't understand why that fixes the problem for me?

tri335 · 05-30-2014, 09:20 PM

I also had similar issues. Fan came on after 3 min from cold start. Ended up have to change water pump and thermostat. Works great now! I have about 54000 miles.

gfuller40 · 05-31-2014, 04:58 PM

When I do the self bleed with the electronic pump, it runs intermittently. 3 2 or 3 second spurts, then a 6 second break and repeat. By feeling the main radiator hose, it's doing the same thing when it is running. Should it be a steady flow?

gfuller40 · 06-09-2014, 07:31 PM

So I replaced the water pump over the weekend and problem solved! It took a good 5 hours (including beer breaks etc...) I did not have to drop the sway bar, just had to remove 3 nuts from where the power steering high pressure line was clamped to the bracket. I was able to remove the pump without disconnecting the thermostat from the rear connection. The pump had to come out backwards and it took a lot of jiggling around but it was possible. All in all, not horrible job, not that fun either and the XI seems to be much tighter than the i's.

Thanks for your input, I was hoping to not have to do that but at least now it's done.

05-30-2014, 04:52 PM	#1
gfuller40 New Member 1 Rep 10 Posts Drives: 2006 330ix Join Date: Dec 2012 Location: Maine iTrader: (0)	2006 330xi radiator fan coming on after cold start Hello - I recently purchased a 2006 bmw 330xi with 100k miles on it. Lately when I start it in the morning, the fan will come on and run almost full blast. This happens anywhere from 30 seconds to a minute or two after starting the car. If I shut it down and immediately start it again, it goes away for whatever duration of the drive I have. Some other observations I've had: If I drive it while the fan is going nuts, it will either shut off on it's own or throw an over heat warning (10 minutes after driving) - shut it down, start back up and it's fine. It only seems to happen once a day, not every time I start it. For instance, it will be fine in the morning, go to start it at lunch and the fan comes on, restart and it's fine. I've replaced the lower radiator hose temp sensor - no luck. I've heard it could be the water pump but I've yet to see any instance where someone has had these very same symptoms. Why would the fan come on a minute after starting the car while it's very cold? I did check the temp when I got an overheat the second time it happened - reading was 115c (via odb) There is another temp sensor by the oil filter but I'm going to hold off on replacing until I get some kind of feedback. No CEL Thanks!
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05-30-2014, 05:39 PM	#2
deeLow DOPE 148 Rep 758 Posts Drives: F80 Join Date: Jan 2014 Location: Earth iTrader: (2)	No CEL but it is possible you have shadow codes that are viewable with diag software like INPA. After you restart, you can drive the car fine for XX amount of miles without an overheat warning?
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05-30-2014, 06:08 PM	#3
gfuller40 New Member 1 Rep 10 Posts Drives: 2006 330ix Join Date: Dec 2012 Location: Maine iTrader: (0)	That is correct, After I restart I have yet to have the fan come back on, it's only at startup.
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05-30-2014, 06:56 PM	#4
El Cheapo Loco douchebaggo 186 Rep 972 Posts Drives: stick Join Date: Oct 2009 Location: CA iTrader: (1)	I had the same symptoms for a couple months before the water pump went at around 90k. So I'm willing to bet yours is the water pump as well. If your water pump has never been replaced at 100k, it's already running on borrowed time. Replace it now before you get stranded somewhere.
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05-30-2014, 08:33 PM	#5
gfuller40 New Member 1 Rep 10 Posts Drives: 2006 330ix Join Date: Dec 2012 Location: Maine iTrader: (0)	After restarting, did the fan turn off? I just don't understand why that fixes the problem for me?
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05-30-2014, 09:20 PM	#6
tri335 Enlisted Member 3 Rep 37 Posts Drives: 2009 335i xdrive coupe Join Date: Apr 2013 Location: Pittsburgh, PA iTrader: (0)	I also had similar issues. Fan came on after 3 min from cold start. Ended up have to change water pump and thermostat. Works great now! I have about 54000 miles. __________________ -- 2009 BMW 335i x-drive Coupe 2000 Honda Accord V4 Sedan with Thule Roof Rack (loved this car!)
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05-31-2014, 04:58 PM	#7
gfuller40 New Member 1 Rep 10 Posts Drives: 2006 330ix Join Date: Dec 2012 Location: Maine iTrader: (0)	When I do the self bleed with the electronic pump, it runs intermittently. 3 2 or 3 second spurts, then a 6 second break and repeat. By feeling the main radiator hose, it's doing the same thing when it is running. Should it be a steady flow?
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06-09-2014, 07:31 PM	#8
gfuller40 New Member 1 Rep 10 Posts Drives: 2006 330ix Join Date: Dec 2012 Location: Maine iTrader: (0)	So I replaced the water pump over the weekend and problem solved! It took a good 5 hours (including beer breaks etc...) I did not have to drop the sway bar, just had to remove 3 nuts from where the power steering high pressure line was clamped to the bracket. I was able to remove the pump without disconnecting the thermostat from the rear connection. The pump had to come out backwards and it took a lot of jiggling around but it was possible. All in all, not horrible job, not that fun either and the XI seems to be much tighter than the i's. Thanks for your input, I was hoping to not have to do that but at least now it's done.
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