Black Flakes in Coolant Reservoir?? - Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community

John Rambo · 07-14-2015, 02:24 PM

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...

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?

Packofcrows · 07-14-2015, 04:29 PM

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.

Scott@HKSUSA · 07-14-2015, 05:44 PM

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.

steve99 · 07-14-2015, 08:45 PM

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

humfrz · 07-15-2015, 01:39 AM

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

humfrz

tyrantcf · 07-15-2015, 03:20 AM

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.

John Rambo · 07-15-2015, 05:36 PM

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

Packofcrows · 07-15-2015, 06:58 PM

Quote:

Originally Posted by John Rambo

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.

07-14-2015, 02:24 PM	#1
John Rambo Senior Member Join Date: May 2014 Drives: Turbo BRZ Limited 6MT Location: Los Angeles Posts: 116 Thanks: 47 Thanked 48 Times in 25 Posts Mentioned: 2 Post(s) Tagged: 0 Thread(s)	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... 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?

07-14-2015, 04:29 PM	#2
Packofcrows hey you, yeah you <3 Join Date: Jul 2012 Drives: 2014 37J FR-S Location: Monterey County, CA Posts: 2,713 Thanks: 905 Thanked 1,259 Times in 809 Posts Mentioned: 38 Post(s) Tagged: 3 Thread(s)	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. __________________ Got my TRD wheels and TRD louvers. Thanks!!!

07-15-2015, 03:20 AM	#6
tyrantcf Senior Member Join Date: Apr 2014 Drives: '16 WRX, CBR1000RR Location: Bakersfield, CA Posts: 560 Thanks: 422 Thanked 369 Times in 213 Posts Mentioned: 18 Post(s) Tagged: 1 Thread(s)	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. __________________ Phantom ESC'd Build Thread (Retired):http://www.ft86club.com/forums/showthread.php?t=75293

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07-14-2015, 05:44 PM	#3
Scott@HKSUSA Join Date: Jan 2015 Drives: 2013 FR-S, HKS V2 S/C Location: Madison Heights, MI Posts: 115 Thanks: 0 Thanked 173 Times in 72 Posts Mentioned: 6 Post(s) Tagged: 0 Thread(s)	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.

07-14-2015, 08:45 PM	#4
steve99 Banned Join Date: Dec 2013 Drives: FT86 Location: Australia Posts: 7,996 Thanks: 1,035 Thanked 4,992 Times in 2,983 Posts Mentioned: 598 Post(s) Tagged: 2 Thread(s)	Did they use the subaru blue coolant or equlivant, if different type of coolant used you may get weird reactions or precipitates.

07-15-2015, 01:39 AM	#5
humfrz Senior Member Join Date: May 2013 Drives: 2013 FR-S, white, MT Location: Puyallup, WA Posts: 30,409 Thanks: 29,793 Thanked 32,808 Times in 16,829 Posts Mentioned: 715 Post(s) Tagged: 2 Thread(s)	It's just little pieces of "stuff"; I wouldn't worry about it ..... humfrz

07-15-2015, 05:36 PM	#7
John Rambo Senior Member Join Date: May 2014 Drives: Turbo BRZ Limited 6MT Location: Los Angeles Posts: 116 Thanks: 47 Thanked 48 Times in 25 Posts Mentioned: 2 Post(s) Tagged: 0 Thread(s)	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

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