[redliner]

Put my brother's 335 on ista D
Got 2 faults of interest...

Water Pump over speed.
Water Pump shut down due to blockage.

Replaced thermostat.

Bleed program runs as it should, except that the radiator fan starts up during the bleed process. Something my 2011 E93 335 N55 DCT does not do.

Anyways, the problem persists.
Any ideas?

Can the water pump fail partially? I mean the water pump runs, and definitely does bleed the system. So it's not 'broken'. Can it be partially broken?

Same with the coolant temp sensor. Can it give correct readings sometimes, and sometimes not? I checked the coolant temp at idle and it crept up with oil temp from cold.

Any idea where I can look? Or is there any test I can do with Ista to help narrow down the problem?

[bryosb]

Pump no good, replace it

[redliner]

Pump no good, replace it

Any test we can do to confirm?

[inspi1981]

100% water pump
Nothing to test

[bawareca]

These pumps are a huge problem, and more than 1 car has caught fire because of the faulty water pump.