rust in the coolant: 2004 S4R ?

[abby normal]

so, flushing coolant i came up with a shyte load of rust flakes and brown
coolant.  anyone ever have this?  what iron exists in the coolant loop?
i'm guessing the impeller is iron (steel), and the spring in the thermostat.  thought
about picking up a new thermostat ... until i found out that they're over $200.
should i take off the pump cover?  seems to maintain temperature, but the
condition of the fluid that came out is bothering me.

[ducpainter]

so, flushing coolant i came up with a shyte load of rust flakes and brown
coolant.  anyone ever have this?  what iron exists in the coolant loop?
i'm guessing the impeller is iron (steel), and the spring in the thermostat.  thought
about picking up a new thermostat ... until i found out that they're over $200.
should i take off the pump cover?  seems to maintain temperature, but the
condition of the fluid that came out is bothering me.

My 996 was like that when I first got it.

Most of the rust seemed to come from the steel hose nipples.

After the first flush and addition of water wetter (it's a track bike) I haven't seen any rust during the annual swap back to antifreeze for the winter.

[Speeddog]

Impeller is plastic.

As dp said, rust from the steel hose nipples on the water pump.

[abby normal]

thanks ... that makes sense.  i ran my finger around inside the water  pump inlet
and pulled out a black sludge.  didn't know the impeller was plastic ... thanks for
the info.