What can happen if there is Dexcool still in system after flushing and going green? The reason I ask is that the color of my water in the expansion tank has turned color to a pinkish. The temperatures are averaging higher on my Ultra Gauge at idle (208- 218F). The average goes down to 203- 208F when driving city but it can rise quickly to 212F at a light.

I performed a coolant test with a Peak Kit and my mixture is also wrong. I have more distilled water than anti freeze. The needle is rock bottom on the kit. I'm thinking that I set off the balance when I bled the air from the system a few days after the first few days twice.

Thanks-

 

You probably have old dexcool sludge in bottom of rad that is now mixing with things. Rad shop may be able to flush, GM had a way to do it with Prestone powder and idle fast for several hours...

 

When I flushed out my Dexcool to replace with universal, I flushed with tap water numerous times, until what was draining, I felt I could safely drink. Being as **** as I am, I removed the left hand block freeze plug and forced low pressure air through the engine, radiator, and heater core, to ensure the tap water was all out before refilling with 50/50 premix.

Dexcool combined with green has many stories about becoming a sludgy mess.

I opted for the test strips from Wix. In addition to freeze point, they also measure PH.

 

I would flush it one more time with distilled water after draining out as much old fluid as I could, then add back using the straight coolant, not 50/50, then add distilled to bring the ratio to where you want it. I would also add a bottle of Water Wetter or Purple Ice to the system.
Yes, you are currently running to warm for these cold days, should be around 202 to 206 for in town driving, high 190's on the road and no more then 206 to 208 at an idle.
Might also consider replacing your t/stat and coolant pressure cap.

 

- Good news is that the T-stat/ expansion cap was replaced two months ago
- Shop wants to run it on straight water with heat on full and repeat flush if necessary/ recommended adding straight coolant at first and then adding distilled to bring it up to the proper concentration
- I'll pass on the reverse flush of the radiator as recommended on this forum
- I will add the Water Wetter again when I get it back and of course follow up

(finger's crossed)