best coolant Ph level-??

[Bill R.]

zerex g48 the ph is 8.1 at 50/50 mix levels. You can test with litmus strips as others have suggested. Here's a couple of documents with some ph info on them from bmw and from zerex for the g48 factory coolant

What is the appropiate/best Ph level for BMW's coolant system?. It is my understanding this is very important for BMWs. Also, how can I test at home? Did not find anyting on ph levels in archives. Tried 3 different ways.

BTW, I use BMW blue with distilled water at all times. Been two years since changed.

TIA

[Russell]

My independent BMW shop with BMW Master Mechanics who have been in business 20 years told me it was important. They see engines with all sorts of coolant related issues and it helps them understand engine condition. They use a pH meter. Google a bit and you will see pH levels and coolant discussed a great deal.

I will prob get litmus paper and test for fun and the "thirst for semi-useless knowledge". Then I will go ahead and change the coolant as it has been in two years.

[Russell]

Thank you Bill for an excellent answer. I appreciate many of the others as well .Wish I knew a lot more of the technical aspects of vehicles. This board has helped me understand what I can work on and what to have a 'professional' work on. As this is my daily driver, I cannot tolerate significant down time.

[ryan roopnarine]

all levity aside, the fact that that chart says that the operational allowance for antifreeze is from 7-11 pH means, almost explicitly, that the pH doesn't matter. pH only goes up to 14. i'd bet that you could subtract the pKa from 7 and be safe down to a pH of 3 and not damage your cooling system (you might have some weird reactions with plastics, but you'd have the same reactions with plastics if you let the ph go up to 11). pH is a logarithmic scale, 4 is a big difference in a place where electrolysis and deposition and owners adding tap water can go on unchecked. if they were going to say that typical operational ph would be up to 9.5, i'd buy that it mattered. i would almost wager a bet that your indy uses the pH as only a small part of the puzzle, that they wouldn't dump the stuff out if it were 11, but they would dump it if they saw rust in it. specing an antifreeze with PO4 for ph buffering (american green) without PO4 buffering (euro/bmw/merc) and then
1) expecting the owner to never put tapwater in the radiator, ever
2) making a perfect 50/50 or 60/40 mixture of antifreeze in bmw's labyrinthe
cooling system
3) (and this is important) making sure that the "distilled" water is exactly 7 ph (utterly laughable)

and then using these criteria to establish a standard for operational PH in your car is unbelievable. none of the university of florida DI plants can produce exactly 7.0 ph deionized water, you have to use buffers with your experiments. they have a great deal to gain by giving their labs clean water, but they can't do it. marine fish shops can't do it, i'd bet your indy's di'er or filter setup can't do it (if they have one), and even if they fill your cars with jugs of distilled from the store, they can't provide it. the second you put anything other than ph 7.0 water into the antifreeze (which is what they used to produce the document bill posted), you vary wildly from spec. add in the nastiness from your motor, and you better believe that that ph is not representative of any kind of dealbreaking standard for antifreeze pH. saying that ph matters when the document specs a ph range of 4 is like me running a conductivity test on my used motor oil to determine fuel dilution. the result may say something, but it isn't saying much.

[ryan roopnarine]

russel, you probably have a great indy, that does work for a price you believe is fair. that's all well and good. it doesn't mean, however, that they can dump ph probes into antifreeze and determine if your coolant ph is going to make your headgasket die in the near future.

[Russell]

Bet you are a student/engineer or similar. My son, a civil engineer, will go into detail on a subject until the entire family wants to hide. No offense. even so, perhaps you are totally correct. interesting real world observation.

[ryan roopnarine]

i used to be an eng. student, now i'm an english major that is trying to go to lawyering school. that aside, the only way i could see an indy telling somebody that their coolant needed to be changed by ph is if it was
1) pristine looking
and
2) some ph test strips they stuck into your coolant resivoir came back with a pH of 2 or 12. then they would be doing you a service by telling you that you needed to dump it on that alone.

and ps

please don't take offense to anything i've said. its just that 4 is a lot

[ryan roopnarine]

yeah, and go buy some of them strips from a fish store--probably the cheapest place you can get them if you cant steal them from work. lets see what yours is. i might do mine, then we can all get together and make an excel graph of the numbers