[alphawawa]

Hi,

A question about the automatic coolant bleeding procedure.

VEHICLE

2013 X3 xDrive35i, 150k miles. Coolant pump has 50k miles on it, thermostat has 15k miles on it.

PROBLEM

Engine fan goes full blast, on for a few minutes then off for a few minutes, from a cold engine start, which seems to imply a dead or failing coolant pump. Thankfully no SES or overheating has occurred...yet.

DEBUGGING

I have not yet been able to read out possible fault codes, so I first tested the operation of the coolant pump by initiating the built-in coolant bleeding mode, where the electric coolant pump runs for about 12 minutes.

QUESTION

For anyone that has done this bleeding procedure - does the pump run *continuously* for the ~12 minutes, or does it go on and off? Mine went on for a minute, off for one, on for 4 minutes, off for one, etc. I just need to know if this on and off behavior is normal or confirms a problematic pump.

Thanks for any insights!

UPDATE

For anyone else's future references, the on/off behavior of the coolant pump during the self-bleed test seems to be totally normal, as seen in these YouTube videos:

I will now work on getting any fault codes in the system to figure out what is going on. Any insights appreciated!

[alphawawa]

Hi,

FINAL DIAGNOSIS

Faults were read out and the only one present was "DME 20A804 Engine Cooling System: coolant pump switched off due to blockage," which confirms that, even though the coolant pump seemed to work just fine during the self-bleeding test and thankfully the engine did not overheat, the coolant pump was still malfunctioning, which caused the DME to max out the cooling fan to protect the engine.

Price to replace coolant pump from a local independent shop here in SF: $1300.