Dark Brown Coolant?

Backstory first...

Just bought a showroom, 64,000 mile, 1999 Lincoln Navigator 4x4, driven 2000 miles since 2014.
Bought it from the Paducah Kentucky police department
Changing fluids along with misc routine maintenance and some minor repairs from non use.

My question is this:

Coolant is very dark brown like root beer but it is not rusty or corroded green anti freeze as it doesn't stain the overflow coolant tank. Don't think it is the orange DEX stuff either. It is very slippery, is not petroleum based as it rinses clean and easily with water leaving no trace but foams like dish soap. In 50 years I have never seen anything like this. Flushed the system for hours to get it to stop foaming and finally run clear out the radiator drain as it has rear heat and holds 28 quarts of fluid. Drove the vehicle for about 100 miles on this stuff in stop and go traffic with no overheating issues.

Just weird.

Mikey

 

Sounds like someone put Bars Stop Leak in the cooling system.

Cheers

 

Hey Mikey... BAR'S LEAKS back in the day had the oil and rabbit pellets in the mix. After mixing with water it looked like coffee with cream in it. Maybe its a new "new" antitoxic anti global cooling, global warming solution thats gonna save the thermostat (@$200.00 !) from needing changed every 12,000 miles. Instead its gonna eat the trans oil cooler and cost you way more $$$ since its a cop job?? ws

 

Mixture of incompatible coolants?

When I added “all makes/all colors “ coolant to my Dakota after the plastic connector cracked to make it to the repair shop the orange MOPAR brand coolant had turned a chocolate brown and the mechanic thought it looked a little “sludgy “ . I label each vehicle with what it has and have 3 different types of coolant on my shelf.

 

Sounds like red coolant was mixed with green.
Turns brown. At least it did when I worked at Toyota.

 

The Evans waterless coolant had a brown look to it after it had been run in my car.

 

I was thinking the same thing, Briz.

 

Thanks guys. After reading the replies I am going with all of the above. LOL!

I never mixed lubricants or coolants so I learned something new.

Flushed the system with some baking soda and then fresh water for over an hour till it ran clean. Gonna refill with the orange DEX as it seems to last much longer before breaking down.

Again thanks guys...

Mikey.

 

Has this car ever been frightened?