What happens when you mix Dexcool and Prestone? DON'T ask me why I brought this up.....

 

I assume you're talking about mixing the orange/red antifreeze and the green antifreeze. I've never done it myself, but I've heard on this forum, and at the auto parts store that I work that they form into a gel.

 

It turns into sludge. It's bad.

 

I have seen the basic statement below stated many times. I have read the same thing said by GM as well.

Most problems people attribute to Dex-cool are not from mixing with the older coolant.

 

I did it by accident cause i was going to switch to dex during a waterpump install since a big mouth friend talked me into it. so i filled the radiator with dex but the block still had green in it I was going to get it flushed as soon as i finished but I ran into other problems and the car sat for awhile. after running for a short period of time when i drained the radiator it was just a lighter orange no sludge.

 

alright, my brother took the Z out, but I just read in my dad's C5 vette's owner's manual that if you fill up with anything but Dexcool the life is reduced to 2 years/30k miles. It says it in black and white....I guess it's now time for me to go flush the coolant in the Z, lol.

 

Basically saying that the properties of the coolant revert to those of the green stuff.

 

awesome, thanks for pointing that out to me shoebox

 

question.. are you talking about the normal prestone thats green or the red extended life prestone?

 

I just got my coolant and all that stuff replaced. The mechanic told me they had the change the coolant, because someone changed it before and you cant mix or your not suppose to mix coolants. He said if you mix red and green it can turn acidic and eat the system apart.