PH of Coolant

Just had my 99 SL2 serviced by my local mechanic who I have done business
with for 20 years. Recently, I had the 60,000 mile service done by the
Saturn dealer which included coolant flush and fill. My mechanic called me
to let me know the PH of the coolant was near 12 which he said was not good
for an AL engine. I called the Saturn dealer and no one there could tell me
what the spec was for coolant PH, in fact, they said they never check it.
Anyone know anything about what the PH should be ? They said if I can come
up with any documentation they would "work with me"

 

http://www.equivashellmsds.com/getsinglemsds.asp?ID=197697

According to the material safety data sheet for a 50/50 mix of Dexcool and
water:

--------------------------------------------------------------------------------
SECTION 9 PHYSICAL AND CHEMICAL PROPERTIES

--------------------------------------------------------------------------------

Appearance & Odor: Orange liquid
Substance Chemical Family: Ethylene Glycols
Appearance: Orange liquid

Boiling Point: 226 ºF

Flash Point: 260 ºF [Pensky-Martens Closed Cup]

Freezing Point: -34 ºF

Odor: Mild odor

pH: 8 - 8.6

Specific Gravity: 1.06 - 1.09

NOTE: The freezing and boiling point values reflect a 50% solution in water
at atmospheric pressure.


So, it appears that the spec is from 8 to 8.6

 

I was about ready to post 8.3 myself. I was in the middle of reading
an interesting editorial I found in a Google search. I never thought to
check the pH in a msds.

Interesting read:
http://www.babcox.com/editorial/us/us60024.htm

 

does the ph change over time or would the ph have been high from the
beginning?


I was about ready to post 8.3 myself. I was in the middle of reading
an interesting editorial I found in a Google search. I never thought to
check the pH in a msds.

Interesting read:
http://www.babcox.com/editorial/us/us60024.htm

 

When doing a flush and fill, it is common to use a "radiator flush"
solution. The normal process is as follows:

1. Drain radiator and block of old coolant .
2. Refill radiator with clean water and run engine for 5 minutes to
circulate.
3. Let cool. Reflush radiator to get more of the remaining coolant.
4. Refill with clean water and add radiator flush.
5. Run engine 5-10 minutes after reaching normal operating temp and with
heater on full hot.
6. Repeat steps 1 through 5, but without adding flush.
7. Backflush system with clean water.
8. Refill system using appropriate amount of antifreeze per desired mix and
system capacity.
9. Crush and add sealant pellets from GM/Saturn dealer if specified for your
vehicle.

I'm speculating here, but it sounds to me like someone used the flush, but
then got lazy and failed to get it all out of the system before adding
coolant. If the flush solution was very caustic (basic) and started with a
high PH then this could account for the high PH in the current mix.

If it was me, I'd do the job over again to make sure it was done right and
to assure you don't cause long term damage to the radiator, and block. This
is especially true if any of the system is Aluminum.

Good luck!

Bob

 

Forgot to add that some of the most aggressive chemical flushes actually
require use of a neutralizer after use... Another possibility here is that
they did not use it or used it incorrectly. In any event the solution is
the same. Do the job over to make sure it is done right.

Bob