OAT ph

[Grad12]

This week I had one of my first issues with the truck. *Knock on wood* I had a small exhaust leak from a rusted and snapped bolt on a coupler on the exhaust system. First, wow did that ever change the back pressure; it drove with a dead pedal and sounded terrible. Second, it was an easy fix but I had to take it to a quick garage because I had no time to change it myself.

The garage I took it to did a check of many other components, coolant included. My coolant ph is at 6.5 and the garage recommended a flush. I said no for now until I investigate. Also, I doubt that garage had Mopar coolant to replace. I've topped up my truck twice so far with Mopar OAT coolant (50/50 not premixed). I eyeball the water and coolant. I've only had to add less than half s quart each time. The system has been checked with no leaks. It's just 5 years old, it may need a top up every couple of years. This coolant is supposed to last 150000 miles and I am only at half of that. The coolant looks "clean". A flush and new coolant would be expensive. I fear I may have just mixed wrong. Does anyone know what the OAT ph in our trucks is supposed to be? I've read that an acidic pH can cause a lot of issues.

I want to test the ph myself with test strips. Second, my attempt to balance it out will probably be to siphon some coolant out and top it up with pure coolant (with a higher ph). I'm trying to figure out how much in a calculation. Any thoughts?

As this is newer coolant, there isn't a lot of info. Anything you guys know would be great.

 

[tidefan1967]

Honestly if it were me I would check it with one of these:


If it still fit solidly in your temperature range and the color still looked good I would run it for a couple more years or at least until you get to 100K miles. Me personally I'm not going to pay anybody to do any maintenance on my vehicles because I don't trust them not to half ass it. On another note what in the hell do you guys do with used antifreeze that are going to reply to this thread? Getting rid of used motor oil is easy, old coolant not so much.

 

[Grad12]

Honestly if it were me I would check it with one of these:

View attachment 174597
If it still fit solidly in your temperature range and the color still looked good I would run it for a couple more years or at least until you get to 100K miles. Me personally I'm not going to pay anybody to do any maintenance on my vehicles because I don't trust them not to half ass it. On another note what in the hell do you guys do with used antifreeze that are going to reply to this thread? Getting rid of used motor oil is easy, old coolant not so much.

Found one of those testers for 8$. I'm picking one up to be sure. The issue I find is the ph of the liquid mixing with the hoses or metal. If the coolant is still good vis the tester, does the ph need to be adjusted? I know this oat stuff is different but a normal engine ph is between 85-10.

As for used coolant, just dump it on the ground. Kidding! We have chemical waste disposal once a month here. Check your locality maybe.

 

[Grad12]

Further reading: " the resistance of aluminum depends upon this protective oxide film. which is stable in aqueous media when the pH is between about 4.0 and 8.5."

To me, it is obvious that I just need the manufacturer specifications on ph in oat coolant in the vehicle. It seems to vary.

 

[Hemi395]

I believe Amsoil makes some coolant test strips....

 

[crackerjack1957]

The proper mix is determined by checking the coolant level; -35 degrees equals 50/50 . The problem comes when the pH of water is 7.0 to 7.2 and antifreeze pH is 10.5 right out of the gallon. A 50/50 mix of water and antifreeze would have a pH factor of 8.75. This level is too acidic for today's cooling system.

http://www.divelys.com/cool.htm

 

[Grad12]

http://www.divelys.com/cool.htm

Good read. Thanks.

 

[Grad12]

Update. Talked to the dealership today as I was in to get an oil filter anyway. The service manager reassured me 240000 km or 10 years for the oat coolant. We didn't test anything. I have a good relationship with my dealer. I trust them. I agree that the other mechanic was possibly looking for a money grab.

For my own peace of mind. I'll be looking further into it with another expert to cross reference.

 

[Tach_tech]

OAT coolant will not give a reliable reading using the old style siphon testers.

To properly test it, you need to use either a refractometer or ph strips.

As well you shouldn’t use tap water to mix the concentrate with.

 

[Grad12]

OAT coolant will not give a reliable reading using the old style siphon testers.

To properly test it, you need to use either a refractometer or ph strips.

As well you shouldn’t use tap water to mix the concentrate with.

Thanks. I've been using distilled water. I knew it would have something to do with the coolant itself being oat. For now, it looks clean and should be fine. Temps are all good. I'm going to brush it off to unnecessary mechanical work for cash.