Anti Freeze/Coolant Replacement Interval?

[Mike K]

I was wondering how often does the system need to be flushed and the coolant need to be replaced?

I've been using BASF Glysantin G48 mixed 60/40 with distilled water, I last did it 2 years ago:
https://www.amazon.co.uk/BASF-106015-Glysantin-G48-Concentrate/dp/B002QQSNE6

Feedback is appreciated.

Thanks and best,

Mike

[Tyler S]

It all comes down to mileage, how many heat cycles, and the pH of the coolant. The coolant turns acidic after a period of time. You can use a ph meter to test. But honestly every two to three years is good insurance against the dreaded aluminum head corrosion.

[TheEngineer]

I have been using Litmus strips. They are small paper strips that turn color when immersed in a liquid and indicate if the coolant is acidic or basic. What does the forum think about that?

[Mike K]

Hi Tyler, thanks for the feedback.

FWIW I dipped a PH Strip into the coolant reservoir and got a PH reading of around 9= Alkaline.

Best,
Mike

[Tyler S]

Looks like your in the ballpark.
Straight water is around 7
Straight antifreeze around 10
50/50 is then 8.5.
However I think this is a bit low and can still cause issues. Keeping it between 9 and 10 would be optimal.

[TheEngineer]

This is very interesting! I am learning something. The Litmus strips I am using come in two small glass tubes each with a cork plug. One is pink and the other blue. The pink one turns blue in basic, the blue one pink in acid. I have had them for many years (40?) and it appears the strips you are using are an improvement?

[ja17]

There are some lengthy in-depth discussions already on this site in regards to type of coolant, change intervals, and specified PH levels for our cars. You mght want to try and search up some of those threads.