Black Flakes in Coolant Reservoir??
 

So there I was, poking around in my engine bay, when I noticed that there were some black specks floating around in the coolant reservoir. I took it out and dumped the coolant out and found that there was a lot of gunk and quite a few of them collected at the bottom...

http://i58.tinypic.com/2m6skxs.jpg


Upon inspection, they don't feel like a hard material and are rather soft. I have FI and a koyo radiator, and had a flush done when it was installed less than 10k miles ago.

So should I do a coolant flush and forget about it? Or is this something to worry about?

It's buildup from internals of radiator, tubes..etc. Its also duo to water if you add 1/2 and 1/2. Not all water is filtered the same. Never use water straight from your hose. Upon heating and evaporating, many of the times it leaves a white-ish residue like salt. Also, some coolants have little floating objects in them we rarely notice to stop micro leaks.

Haven't done it on my car, but on my truck I flushed coolant, pressure washed what I could, added coolant again, ran truck for a 45mile round trip, flushed it out again and finally added coolant once more. I still notice stuff like that though. It is a waste of coolant following my actions... There's also these mini filters you can buy. Maybe another member can shed more light on them.

Typically that will just be debris from the cap seal or any of the rubber lines in the system. If it's soft like you say, I'm confident that's what you're seeing. It's common with new cars, won't hurt anything, and will eventually cycle out with regular maintenance.

Did they use the subaru blue coolant or equlivant, if different type of coolant used you may get weird reactions or precipitates.

It's just little pieces of "stuff"; I wouldn't worry about it .....:)


humfrz

First time I read the title I saw it as saying: "Black flakes in my corn flakes" for some reason.


Glad it was merely the coolant overflow tank.

lol about the corn flakes. Had that happen once. It was a family of moths.

Thanks for the replies, I think I'm going to do a coolant flush and forget about it. I was meaning to do one anyway to run straight water + mocool or water wetter to help with temps in the summer.
The tech at Evasive Motorsports said it's common on the WRX and I shouldn't worry about it

Found cockroach leftovers in my Kix at age 5. Ate around cockroach shells. Had to remind me of that. Being poor was always a b!tch.