Flush the Radiator Coolant?

Not for Jeeps but VW/Audi use 2 proprietary coolants possibly made by by Valvoline. This coolant should not be mixed with any other coolant or it will sludge up pretty bad. Now VW has a "Universal" coolant that can be mixed with either of their coolants. So the tally is up to 6-7 different coolant types. ;-)

I have seen this before, thick and kinda grayish-black, and I attributed it to never changing the coolant and mixing different types together. I also noticed that this solution ate up the metal sensor bung inside of the black plastic radiator in a VW. Engine was fine and kept running for years until another vehicle took it out.

It used to be a time that you were suppose to change the coolant every two years along with a proper flushing. Of course it was also recommended that you change the motor oil every 2-3 months too! lol Times have changed some.......... I know that certain oil filters (VW and Audi) have recommendations that you can change them every 2 years or 24,000 miles. Of course you will need very good synthetic oil too! ;-)

This some nasty stuff I had to flush out.

One out of many daves did pass the time by typing:

One other possibility is that goo was several tubes of stop-leak or such radiator killer in a tube. I've seen that before at some shady used-car dealers.

Well it should not have been on this vehicle. I knew it since it was new, so the only other way it could have gotten in the system is by the hands of the dealer techs. It seemed more like something was disintegrating or dissolving in the cooling system. Might have been the water pump now that I think about it, but it should not have caused the radiator sensor bung to erode.

mystery! lol