Milky grey sludge

[RavenTai]

similar stuff shows up in Toyota Land Cruiser systems

http://forum.ih8mud.com/index.php?board=2;action=display;threadid=7062;start=msg58369#msg58369

I do not know what it is but my best guess is byproduct of aluminum corrosion

I would flush the cooling system out as best you can and refill with new coolant

 

[Spector]

Interesting story. Assume the dealer replaced with an OEM radiator but don't know if aluminum or not or if the Red coolant reacts with it. Sure could be dissolved aluminum, looks the part and it looks exactly like the description at that web site.

 

[edwardh1]

My Nissan with factory green went 5 years. Spotless, no sludge. I can not tell the 5 year old fluid from the new mix I added.

 

[Spector]

About one year ago I had the radiator replaced and Toyota filled the coolant with the Toyota Red. OEM on this Camry was green ethelene glycol. Water pumped repalced about a year before the radiator.

Now, slight coolant seepage but only when temp is overnight below 20 degrees and noticed today that overflow tank had a greyish white sludge the consistency of oil ( no oil seemd present in coolant) thicker then coolant anyway. All of this sludge seemd to settle on the bottom of the tank. I flushed and cleaned the tank and refilled the tank with new coolant.The system was flushed when the radiator was replaced a year ago. I have seen gunk in overflow tanks before, but nothing like this stuff. Sort of like the stuff people see on their oil fill necks when condensation is building up but this is more liquid in form.

Thoughts as to what this greyish white sludge is, quite a bit of it actually.

Plan now is to see if it recurs in the overflow tank and depending on this have it flushed next month when the inspection is due.

 

[toyvwbenz]

my 94 Toyota pickup had the same grey sludge in the overflow tank on the OEM red fluid. Flushed it out and put in some VW G12 pink coolant($$$) and it hasn't sludged up yet. It did look like dissolved aluminum. I thought the Toyota coolant was designed to protect aluminum.