I must have a slow leak somewhere as my coolant reservoir has gotten low triggering the Coolant Dash Light. Went to top it off with Zerex G-05 50/50 and saw that my coolant was GREEN???

Is this good for the car?

How do I test/confirm what type of coolant my car is using to top it off correctly?

Pics below:

 

antifreeze has different colors, i use prestone and have always had good results with distilled water. Every dealer tries to sell some special brew that is proprietary and expensive. If in doubt, flush and refill, there is a lot of junk in older coolant that needs to be removed. I took the blue goo out of mine when I bought it 2 years old and STRAINED THE OLD FLUID to see the gunk in it. That is an interesting exercise to try when changing the antifreeze if you have not done it before. Woody

 

The OEM coolant was blue and when I cleared the system quite thoroughly and added the yellow Zerex the coolant in my tank turned to green. It does not take much blue coolant to turn the yellow to green.
If I was you I would take this opportunity and replace the coolant, then you will know what you have is OK.

 

So if I flush the system completely, it's safe and okay to use any coolant, regardless of whether or not it is a HOAT coolant?

As long as it's a full flush, is it safe to say I can put any coolant I want and stick to it (just never mix at any one time)?

 

Suck some out in the tester, it may not be green, but looks green when looking in the reservoir. I used the GO5 on my last fill but am convinced that any of the green stuff that can be used with aluminum will work.

James

 

The maker specifies HOAT coolant and that is what I recommend you use. I believe the color is a dye added to the fluid at the manufacturer. Why try and save money on something that could cost you big bucks if you used the wrong fluid?

 

Sometimes a manufacturer will recommend a particular product to be or sound more environmentally friendly. That doesn't mean the regular stuff will cause damage and can work as well.

I have been through this with Saturn years ago when they specified a particular antifreeze.
Turns out in the end the dealer was using just the regular green stuff.

GM recommends Dexcool. The first thing I do if I buy a used GM is dump that crap out, flush, and refill the green. Ask others what problems Dexcool can do but GM recommends it.

 

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So, back to my original question:

How do I test/confirm what type of coolant my car is using to top it off correctly?

 

Everyone is saying , flush an fill. It would be like trying to decipher what brand of gas was last used....

 

I doubt that the level of that coolant would cause the light to come on, there is another problem to my thinking.
Coolant is not good for ever, flush and refill with Zerex after finding the problem.
To see if I am correct, fill it with distilled water to the top of the plastic indicator and see if the light goes out. I’m betting it will not.

 

Hopefully its not a leaking inter cooler. Pull the manifolds and check if coolant is present.

 

Sorry to semi-necro thread here, but it was the freshest I could find in a pinch lol. I'm having the damndist time trying to find zerex in my area as my rad light has started to flick on an off a bit. Was wondering if this would be compatible? Spotted it while looking for some oil at the store. Hopefully I can get a quick reply before I leave lol!

 

If it is just low enough for the light to flicker, I would just add water. I personally do not like to mix coolant types. Add water, drive for a day or so and then check freezing temp.

If you do not have a leak, it is natural for the water to evaporate out of the coolant if the pressure gets above the cap rating. Water evaporates much much faster than antifreeze.

 

Thanks for the quick reply James, I'll try that to get by for now, on the off I can't locally source Zeerex G05, would this act safely as a replacement (as in flushing the system, it's likely due anyway) as it is labeled Mercedes hoat, but this is honestly first time I've had to deal with specifics in dealing with antifreeze lol.

 

Autozone generally has Zerex G05

 

I'm curious, what's the worst that can happen if I top off my coolant with three cups of distilled/purified water to avoid having to potentially mix incompatible G05 coolant?

My Zerex G05 is Clear BTW.. not sure why.

 

No problem with topping off with distilled water, especially in Los Angeles.

 

Its been 3 months since you started this posting, antifreeze is not going to do anything bad, they are all similar, if your still concerned, dump and refill of gosh sake. Its no big thing, Id use prestone in every car, they are known and proven. Al is Al. Woody

 

Nothing. In fact running 100% distilled water is the best thing to do to keep your car at its coolest. Unfortunately, that's only viable for race cars that are garage kept and don't see daily driving duty. You'd need to live in a warm state that never gets below freezing as well.