I replaced my radiator last fall and switched to green coolant. At the time, I back-flushed the heater core and ran distilled water through the system twice, then drained it and filled it up with Peak. Now the fluid in the reservoir's looking orange again. Could this just be crap getting stripped off the inside of the block and hoses? I just ordered the full hose kit from AB (I'm due) so I'll dump out whatever coolant I can when I replace the hoses and add more green stuff but this is nuts. Anybody else ever have this happen?

 

Same thing happened to me after I decided to flush out the dex in my 99 when I replaced the thermostat. Was orangish in a little over a month. I've since flushed it 2 more times bc it kept turning orange. It's finally staying green after 3 flushes and 2 years of going green multiple times.

 

Man, that stuff is tenacious. I'll just keep draining and adding until it's all green. This is actually the second time it has had green coolant added. Right after I bought it, I had a shop check it out and change the thermostat and coolant but they never did a full flush like I did. I should have all the Dex out of it by the time it's ready for the crusher.

 

Hmm, that's odd - I had my dexcool flushed out and replaced with Prestone Green stuff as well and noticed that it looked orange through the reservoir afterwards. I thought it may have been a little residual that floated up into the overflow tank, but now I think it must just be some odd thing with Dexcool! I am sure someone else topping it up would just think to add dexcool becasue it is orange....

 

Dexcool can and does stain the inside of the white plastic reservoir, but that is nothing to worry about. If you use Prestone brand green color antifreeze that says on jug that it is compatible with ALL brands antifreeze, including Dexcool, it IS compatible, so small fraction of any remaining dexcool in your system is nothing to worry about either. Each summer, drain out some, replacing it with same Prestone compatible antfreeze, and you will be OK., but be sure to always use ratio mix of 50% Prestone to 50% water, to get maximum protection of all aluminum throughout coolant system, especially throughout all aluminum engine interior.

 

It may be the old cooling tank that is causing it all or atleast some, although I'm sure the old hoses aren't helping. But, the third time I flushed it was because I was replacing my cracked tank.

Maybe it was all finally flushed out by then or maybe having a clean tank did the trick..who knows..