NNN1

Ok one simple question. I own a 2005 1500 silverado HD 4x4. my question is. Can the green Prestone anti freeze be mixed with the orange stuff currently in the truck? Also, will it hurt the engine if I were to flush the orange stuff out and refill with the green stuff? Thanks.

muddin61483

I am not really sure if you can drain it and add the green but i do know for sure you can not mix the two. I know i have heard you can flush it out and put the green it but i have never done it.

JK23112

I would stick with the original (orange) stuff. I had mine flushed out & refilled back in March. The GM mechanic said that the truck was designed to run on the Dexcool coolant - so why bother switching? Just change it often enough (every two years, perhaps) and you'll be just fine.

It is true that you can't mix them, though, as they both have different chemical properties which cause them to "break down" each other & possibly cause trouble for you and your engine.

MDTAHOE

Your cooling system is designed to run DexCool as previously stated. If you really want to change to something different then get a coolant that is compatible with any make or model. However as long as you maintain the Dex regularly it will be OK. Replace the rad cap every other year, fix leaks as soon as they occur and flush it every 2-3 years .

wellmax

my friend poured green into his truck that had the orange and the coolant turned to a mud like substance. had to have the complete system flushed and boiled out at a radiator shop.

when my water pump when out in no-wheres-ville AR the mech installed a yellow coolant, i ask him about it and he said it mixed with either green or yellow, must have been right as I have had no problems with it in 25K miles.