Recent Topics
Interesting Read
by montero1 - 05/25/20 03:19 AM
1991 Indy 500 Pre-Race
by IMSA_Racing_Fan - 05/25/20 01:46 AM
Repairing acid stained wheels
by IMSA_Racing_Fan - 05/25/20 12:30 AM
Collection of Euro Oils
by js1956 - 05/24/20 10:29 PM
00 grease in my brush mower
by Elkins45 - 05/24/20 09:55 PM
Coolant UV Dye - for without flushing
by Ndx - 05/24/20 09:10 PM
STP S8A C&P
by mpack88 - 05/24/20 07:50 PM
Aprons
by buck91 - 05/24/20 07:35 PM
Oil Additives for GDI engines
by Drew99GT - 05/24/20 07:21 PM
Memorial Day - Veteran's Cemetery
by JeffKeryk - 05/24/20 07:18 PM
CQ Blue, made by who?
by AJB0009 - 05/24/20 06:45 PM
recommended 5w30 for ticking and engine noises
by apollo18 - 05/24/20 06:29 PM
need new group 65 for my F-150, here's my choices:
by DirtyApe - 05/24/20 06:23 PM
Castrol EDGE cleaned my funnel
by AJB0009 - 05/24/20 05:29 PM
Metal Cloak FAD + Fox Steering Stabilizer
by 2015_PSD - 05/24/20 04:55 PM
Blue Driver OBDII
by Al - 05/24/20 04:50 PM
Newest Members
BBC_bias, rabblrouzr, Modoi, zx6rsi, Chumpchange
71522 Registered Users
Who's Online Now
16 registered members (emod, cjcride, blufeb95, fastflyer, FordCapriDriver, Char Baby, 1 invisible), 1,150 guests, and 30 spiders.
Key: Admin, Global Mod, Mod
Forum Statistics
Forums67
Topics305,829
Posts5,281,093
Members71,522
Most Online4,538
Jan 20th, 2020
Donate to BITOG
Print Thread
Hop To
Page 1 of 2 1 2
pH spent coolant? #4035907 03/11/16 08:56 PM
Joined: Jun 2004
Posts: 337
D
deoxy4 Offline OP
OP Offline
D
Joined: Jun 2004
Posts: 337
I work in a lab and have the opportunity to check the ph of my coolant. An acidic pH is one indicator of spent coolant, as it has lost its ability to buffer.

Honda 50:50 coolant has a pH of 7.9 according to Honda MSDS. I follow Honda's recommendation for coolant change which is 5 years/60,000 miles after the initial factory change. I haven't experienced a problem. However, I would like to measure the pH of the coolant, pre-summer and pre-winter, to give myself a little peace of mind. I would also check the specific gravity with one of those inexpensive testers. I am not that concerned to send out a sample for analysis.

A pH of 7 is neutral and in need of change but at what pH is coolant spent?

Re: pH spent coolant? [Re: deoxy4] #4035912 03/11/16 09:02 PM
Joined: Dec 2010
Posts: 2,008
A
abycat Offline
Offline
A
Joined: Dec 2010
Posts: 2,008
depends on the coolant. you would have to measure the ph in the same coolant but brand new. thats the only thing needed to establish trends and any kind of data. also make sure all the coolants tested are the same temperature for accurate results.


2017 dodge caravan gt
2011 nissan versa hb
Re: pH spent coolant? [Re: deoxy4] #4035923 03/11/16 09:10 PM
Joined: Jun 2004
Posts: 337
D
deoxy4 Offline OP
OP Offline
D
Joined: Jun 2004
Posts: 337
pH of Honda type II coolant is from their Material Safety Data Sheet, so that would be "new" coolant being 7.9.

Samples would be at ambient temperature which I would assume that Material Safety Data Sheet testing would imply.

Re: pH spent coolant? [Re: deoxy4] #4035927 03/11/16 09:13 PM
Joined: Jun 2004
Posts: 337
D
deoxy4 Offline OP
OP Offline
D
Joined: Jun 2004
Posts: 337
Here is some information that I was able to find from a machinery maintenance site.

In general, coolants degrade over time as the ethylene glycol breaks down into primarily glycolic and formic acids. Degradation occurs more quickly in engines operating at higher temperatures or those that allow more air into cooling systems. The coolant should be tested on an annual basis if it is intended to operate the system for several years between coolant changes, and particularly where the coolant is used in severe applications. One test ensures the pH is still above 7.0. Some coolant technologies can protect as low as pH 6.5, however, it is typically not good practice to allow a coolant to operate below a pH of 7.0. Glycol breakdown products are acidic and contribute to a drop in pH. Once a coolant has degraded, due to glycol breakdown and pH drop, engine metals are at risk for corrosion. Coolant degradation can be slowed by using coolants with extended life inhibitors and by ensuring that the equipment is operating correctly and within designated design limits.

It appears that they feel that a coolant change would be necessary at a ph of 7.0 or below.

Re: pH spent coolant? [Re: deoxy4] #4035956 03/11/16 09:37 PM
Joined: Aug 2006
Posts: 10,054
C
Colt45ws Offline
Offline
C
Joined: Aug 2006
Posts: 10,054
Makes sense. Anything into the acidic range might start eating into the cooling system. However slowly.


-Colton
2002 Ford Crown Vic PI 207k, Ex-Kootenai County, ID Unit #42
Down for engine swap
2003 Ford Crown Vic PI 86k
Pennzoil Conv HM 5W30, Fram XG2
Re: pH spent coolant? [Re: deoxy4] #4035977 03/11/16 10:12 PM
Joined: Mar 2008
Posts: 9,647
S
slacktide_bitog Offline
Offline
S
Joined: Mar 2008
Posts: 9,647
Newer Hondas have a much longer interval, which can be over 100k when done according to the MM. What is the pH of Type II with 100k on it?

Re: pH spent coolant? [Re: Colt45ws] #4035978 03/11/16 10:14 PM
Joined: Sep 2015
Posts: 4,428
69GTX Offline
Offline
Joined: Sep 2015
Posts: 4,428
Makeup water systems for boilers are typically kept in a pH range of 8-9. Boiler chemistry itself is usually inside the range of 8.4-10.6 depending on pressure and amount of additives.

From what I can find coolant pH is similar. Optimum would be in the 9.0-10.5 range. Straight demin water is approx 6.5-7.0 while straight anti-freeze is up around 10.5+. Another factor of coolant age is the electro-chemical reaction current flow or electrolysis. Apparently DexCool and other LL/PG coolants run at a lower pH than EG.


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

2001 Lincoln Cont 4.6L DOHC/ 50K mi / QS HM 5w30 / FUG XG2
1999 Camaro SS M6 /19K /Mobil 1 0w40 /Fram UG /GM MTL-ATF
1969 Ply GTX/RRs
Re: pH spent coolant? [Re: deoxy4] #4035986 03/11/16 10:30 PM
Joined: Aug 2006
Posts: 10,054
C
Colt45ws Offline
Offline
C
Joined: Aug 2006
Posts: 10,054
Dexcool is still EG, not PG.


-Colton
2002 Ford Crown Vic PI 207k, Ex-Kootenai County, ID Unit #42
Down for engine swap
2003 Ford Crown Vic PI 86k
Pennzoil Conv HM 5W30, Fram XG2
Re: pH spent coolant? [Re: deoxy4] #4036001 03/11/16 11:12 PM
Joined: Jun 2004
Posts: 337
D
deoxy4 Offline OP
OP Offline
D
Joined: Jun 2004
Posts: 337
Honda Type II coolant is ethylene glycol based and is pH 7.9 according to their MSDS.

Re: pH spent coolant? [Re: 69GTX] #4036173 03/12/16 08:33 AM
Joined: Jul 2014
Posts: 1,364
Number_35 Offline
Offline
Joined: Jul 2014
Posts: 1,364
I wonder if RMI contains something quite basic (in the chemical sense) that increases pH?

Re: pH spent coolant? [Re: deoxy4] #4036212 03/12/16 09:31 AM
Joined: Sep 2012
Posts: 5,752
D
DBMaster Offline
Offline
D
Joined: Sep 2012
Posts: 5,752
This is just a thought. Let me know what you think. I add 1/2 TSP of baking soda to a gallon of R/O water I keep in the fridge. It raises the pH from 7 to around 8. I find that drinking this instead of the straight R/O water reduces my heartburn a bit. Do you think that adding a similar amount of baking soda to R/O or distilled water prior to mixing with coolant would be beneficial in any way? It does dissolve completely and I have never seen any precipitate in the bottom of my refrigerator jug.

Re: pH spent coolant? [Re: deoxy4] #4036226 03/12/16 09:45 AM
Joined: Dec 2005
Posts: 14,178
K
kschachn Offline
Offline
K
Joined: Dec 2005
Posts: 14,178
Well it is going to be "spent" when the pH changes from what the buffer attempts to hold it at. But by then it is too late of course as the pH will change rapidly from then on.

I don't know specifically how coolant is buffered but I would think that to get a sense of the remaining life (in regards to the buffers at least) one would want to titrate a sample and compare that to what you get with virgin coolant. pH is just the current status of the coolant and doesn't tell you what the remaining ability of the coolant is to neutralize acid.

Specific gravity only shows concentration as I'm sure you know, and that shouldn't change from when it is originally mixed unless you are adding water or something.

Originally Posted By: deoxy4
I work in a lab and have the opportunity to check the ph of my coolant. An acidic pH is one indicator of spent coolant, as it has lost its ability to buffer.

Honda 50:50 coolant has a pH of 7.9 according to Honda MSDS. I follow Honda's recommendation for coolant change which is 5 years/60,000 miles after the initial factory change. I haven't experienced a problem. However, I would like to measure the pH of the coolant, pre-summer and pre-winter, to give myself a little peace of mind. I would also check the specific gravity with one of those inexpensive testers. I am not that concerned to send out a sample for analysis.

A pH of 7 is neutral and in need of change but at what pH is coolant spent?


1994 BMW 530i, 252K
1996 Honda Accord, 288K
1999 Toyota Sienna, 434K
2000 Toyota ECHO, 284K
Re: pH spent coolant? [Re: abycat] #4036242 03/12/16 10:03 AM
Joined: Dec 2005
Posts: 14,178
K
kschachn Offline
Offline
K
Joined: Dec 2005
Posts: 14,178
Originally Posted By: abycat
depends on the coolant. you would have to measure the ph in the same coolant but brand new. thats the only thing needed to establish trends and any kind of data.


You would want to titrate it, unless all you want to know is when it has already lost its ability to buffer.


1994 BMW 530i, 252K
1996 Honda Accord, 288K
1999 Toyota Sienna, 434K
2000 Toyota ECHO, 284K
Re: pH spent coolant? [Re: DBMaster] #4036436 03/12/16 02:06 PM
Joined: Jun 2004
Posts: 337
D
deoxy4 Offline OP
OP Offline
D
Joined: Jun 2004
Posts: 337
Originally Posted By: DBMaster
This is just a thought. Let me know what you think. I add 1/2 TSP of baking soda to a gallon of R/O water I keep in the fridge. It raises the pH from 7 to around 8. I find that drinking this instead of the straight R/O water reduces my heartburn a bit. Do you think that adding a similar amount of baking soda to R/O or distilled water prior to mixing with coolant would be beneficial in any way? It does dissolve completely and I have never seen any precipitate in the bottom of my refrigerator jug.


May well have an effect. Honda's coolant is primarily ethylene glycol, potassium hydroxide, and some inorganic and organic acid salts probably used as extended life inhibitors. Water chemistry and coolant chemistry may be different animals. I don't know if it would be a good idea to mess with their designed chemistry.

Re: pH spent coolant? [Re: deoxy4] #4036452 03/12/16 02:34 PM
Joined: Dec 2005
Posts: 14,178
K
kschachn Offline
Offline
K
Joined: Dec 2005
Posts: 14,178
Originally Posted By: deoxy4
May well have an effect. Honda's coolant is primarily ethylene glycol, potassium hydroxide, and some inorganic and organic acid salts probably used as extended life inhibitors. Water chemistry and coolant chemistry may be different animals. I don't know if it would be a good idea to mess with their designed chemistry.


Well the coolant in the car is about half water so the effect is going to be the same.


1994 BMW 530i, 252K
1996 Honda Accord, 288K
1999 Toyota Sienna, 434K
2000 Toyota ECHO, 284K
Page 1 of 2 1 2
Previous Thread
Index
Next Thread

BOB IS THE OIL GUY® Powered by UBB.threads™