I have my 2004 TL w/ 34,000 miles in the shop now for an oil-change, they just called me to tell me that the Antifreeze has a high PH and needs to be replaced.

I don't have a copy of the maintenance schedule (it's i, but this seems kind of early for a coolant change (it's just a bit over 4 years old).

Does this sound right?

 

You don't need your maintenance schedule. Just go to Acura's Owners Link
and sign up. From there you can go to Maintenance Minder and then follow the link to the owners manual. In the manual you'll find that engine coolant should be changed when a "5" comes up in the maintenance minder.

If you went into the dealer for an oil change, why are they checking the ph of the coolant? Sounds like they're looking for more of your money. At the least I'd ask them what the ph reading is and what is the acceptable range. At the most, I'd ask them why they are performing inspections that you haven't requested.

 

thanks for the quick response. It's not a dealer, it's a local service center that I've been using for a few years. They check all the fluids as part of their oil change service (yes, obviously they do it to find more revenue opportunities). They called me and told me that the coolant should be changed, but all other fluids were fine.

They've been honest in the past, so this is the first real question I've had about one of their recommendations.

Thanks for that link - interestingly enough it says to replace the brake fluid every three years, yet this shop told me the break fluid tested fine.

I haven't seen the "5" come up yet, my oil life was under 20% as of today so the maintenance minder "change oil now" message didn't come up yet, but it had been seven months and 5,000 miles and I didn't want to wait any longer.

At what point are folks generally getting the "change engine coolant" indicator (age/miles)?

 

The AntiFreeze/Coolant don't need to be changed until 100k

 

I'm assuming there's a time element involved as well? I've got just 34k on the car in just over 4 years, so it's probably being driven in the worst way possible (very short trips mostly)

 

The service schedule is a joke!

Brake fluid needs to be FLUSHED every year to prevent contamination and bad
expensive things from happening to the ABS and calipers

Coolant- 4 years is a good time to do it. If the PH is off for any reason you are
making a habitat for things that destroy heater cores.

If you bought your car used- change everything including the trans fluid.
DO NOT let the shop do it- read how in here and DIY the right way

 

I know pretty much squat about engine coolant chemistry but went on and did a few quick searches. Over at "Bob is the Oil Guy" they have a very limited section on coolant. There was only one Honda/Acura test report that showed that after 45,000 miles one car had engine coolant with a ph of 8.3.

I then did a search for "coolant ph" and found a site that stated...

"To combat corrosion, one must monitor the rate of corrosion within the cooling system. The rate is caused by a number of factors, including the acidity or alkalinity of the coolant. The acidity and alkalinity is measured on a pH scale and is very important. If the coolant remains alkaline, corrosion is inhibited but if it becomes acidic, the coolant begins to eat away at the interior of the system.

The alkalinity of an antifreeze/water mix varies because of the additives used and the ingredient ratio but should be between the pH range of 8 and 11. The average antifreeze pH value is 10.5. When the antifreeze is mixed with water and added to the cooling system, the pH decreases to 8.5 to 9. A higher pH level is not always better because some new long-lasting coolants have a pH of 8.3. As long as the pH value stays stable, the cooling system is fine.

Monitor the condition of the corrosion-inhibiting additives in the coolant with the IQ120 pH meter. Low pH readings- below a pH of 8- indicate bad coolant and signal that it’s time for a change. Find out what pH level the coolant can drop to in certain vehicles. Some Asian model cars have newer coolants that last longer and can drop to a pH of 7 before the coolant goes bad. pH readings are critical because they let the driver know when it’s time to change the old coolant before the vehicle begins to have problems. pH readings will not predict how much life the coolant has left, but will help determine the condition of the coolant effectively."

So with very limited knowledge about engine coolant, and based on the website above that states that it is low coolant ph that is the problem, why did your engine coolant test with a high ph?

 

Chemical reaction with engine or water at extreme end of specs or bad luck?
Why not just error on the side of safety and change it. $35.00 or so over four years is not bad imho.