Small flakes in coolant

[mattatk]

G'day All,
Have found lots of small (no bigger than 3mm in size) black flakes in coolant reservoir. They appear to be plastic. Temperatures are all running fine.
I understand the flakes could be from water pump impeller, is there any way to check it's serviceability without pulling it out?
Does anyone have experience with these flakes & possible causes?

Thanks in advance,
Matt

986 Boxster S (2001) manual.

[JFP in PA]

If you have x-ray vision, yes; otherwise pull the pump out and look at it. There isn't much else that can create "black flakes" in the cooling system..........

[mattatk]

Thanks JFP for the quick reply, my "spider senses" were telling me that was the only solution.

[mattatk]

Just out of interest, the flakes turned out to be the impeller failing. Water pump died a month ago, quick easy job to replace the pump. Good DIY one.