This unit came in with the complaint of oil in the coolant. After further inspection it was determined two kinds of coolant were mixed in and ran forever. This stuff is like gelatin and is packed in every cooling passage you could think of. Day two of flushing is started and its still pushing gunk out.

Not sure what the application is on this beast, but Ill bet the heater core and radiator are toast!! Being how black it is, could it be a possibility of oil being mixed into the coolant as well? Even just antifreeze I dont think would turn black like that, but I have been wrong many times before.

Looks to be a mix of ethylene glycol and dex, correct?

I wonder how hot it got.

 

 

I've seen  a blown head gasket  turn the  coolant  dark.. but this  is  waaaay  beyond  that!

I typically stay with Green coolant but this last batch was Yellow SuperTech. But before ever adding coolant I always make sure to flush the system out and start over fresh with one color of coolant.

All I can think of is what a nightmare the EGR cooler on that cm870 being filled with that stuff must be, I don't think it ever would come clean.    

I know of a guy that had a GM vehicle that had the same thing happen. The previous owner (or somebody) mixed Dex with the green stuff and he had the same problem.

We have a hemi at work and the local shop mixed the coolant. I noticed this on my daily inspection. Less than a week later they were putting in a heater core and water pump

Believe it or not 30 min. of flushing the egr cooler and heater core cleaned them up. The radiator was sent out and had the tanks pulled off to be flushed. Not a drop would come out of the radiator it was so packed. With the clutch replacent its already at $6k but , Monday will tell if it's going to flush completely. I've got a nice big box of lemon scented Cascade ready to do some work. As for overheating....only 2 counts of 230-240, way less than I was expecting.

Cascade?, hmm