Mixing Green and Red Coolant
 

Hi there,



I have an 88 jeep cherokee 4.0l. So I have seen a couple of threads on this already, but I was in a jam in the mountains yesterday with a coolant issue and fixed the problem, went to a gas station to get more coolant and all they had was a red coolant. It says that it is compatible for cars using dexcool but does not say only for dexcool cars. It is prestone 50/50 extended life, it says on the back approved for all general motors cars and all other cars and light weight trucks that have aluminum radiators. I only put less than two quarts in and when I got home topped it off with the green stuff that has always been used. All of my friends say it is fine to mix the two, but when I hop on the internet there are a ton of stories about why you shouldn't mix and some sort of sledge develops. Does anyone know if this is true? I can flush the system but I didn't think it was that big of a deal.

I would do a drain and fill, it's probably time to change the coolant anyway.

Absolutely flush it. Dexcool does not like to mix with other types of coolant and will develop sludge. Dexcool is also slightly acidic and can eat gaskets and seals that weren't specifically designed to work with it.

Your Jeep should use conventional green coolant. If you want to use a long-life coolant, Zerex G-05 is probably the best option, it is what is used in newer Ford and Chrysler vehicles as well as others. But I'd probably just stick with green and change it every two years.

Next time if the outside temp isn't freezing, I'd just put water in there to get you home.

Thanks for the help and advice, I will do that!

I mean if you only lose a bit, not completely empty.

Dexcool doesn't mix well as others have said. Drain, flush and fill with normal green coolant/water!

This^^^ I ran into this issue on my diesel as its got red juice and couldn't find any

definitely flush it right away, I'd run the jeep with just water until it got to operating temp and flush again...

then add the favorite topping of your choice :D

I had a water pump go out on my F150 4.9L I6, and when I opened it up it was orange inside, looked like dissolved rust or red clay mud. Radiator was also almost completely clogged. Took me the better part of a day to flush the Radiator and the engine block. Turns out my ExGF had filled it up a few months before with the Dexcool I had behind the seat to go in her Trans Am.

Funny she almost killed that one by filling up the coolant, and she killed my Ranger by not filling up the coolant.

I am not being a smart butt here, but could you have just added water
from the gas station.:pinch:...

The crew doing a cement job for me, were late getting started. They had run out of coolant on the way here, and had to walk 2 miles or so to get water for their truck. I ask them why they did not use some of the water from their 5 gallon ice cooler, rather than doing a long walk:sweatdrop:....

Exactly-That's why it's called Anti-Freeze not Anti-Boil. It's a pressurized system so straight water is ok because at 15PSI, it won't boil until 220 +F. The anti-freeze does increase the boiling point slightly but a 50/50 mix has a lower heat capacity than pure water so it needs to circulate more to have the same heat removal capacity of just water.

In a pinch during warm weather it would be better to use tap water than try to use some other non-compatible coolant. But I think I would drain it out shortly thereafter since there's no anti-corrosion or other additives and straight tap water would probably scale up your rad if left in.

My $0.02.