How Often Top Off Coolant is "Normal"

Maintenance/Repairs
1

2014 Acura TSX, 157k miles, this car has an overflow coolant reservoir

Yesterday I noticed a bubble sound when shutting off car. I noticed the coolant level in the reservoir was at the MIN mark. Thankfully the car didn’t run hot. After letting the car cool off, I toped it off to the MAX line. The problem is I did a complete drain and refill about 30k miles ago. This seems excessive to me, for the level to go from MAX to MIN in ~30k miles. I don’t know if this is normal?

I haven’t noticed any leaks, but based on the rate I’m loosing coolant it seems like I’m loosing coolant somewhere.

I didn’t have the chocolate milkshake of death the last time I did an oil change, but I do have to add about half a quart of oil every 3k miles of conventional oil, when I was using synthetic it was a quart of oil every 3k miles. I put a die in the oil, and there doesn’t appear to be any leaks.

I have one of those radiator pressure test kits. Were basically you connect an adapter to the radiator were the cap normally goes, connect a hand pump, and pressurize the system. Then you can check for leaks or listen for a hissing sound. The only problem is I can’t find a procedure on how to do this in ShopKey. There is no pressure marking on the radiator cap, and I don’t want to over pressurize the system, so I’m unsure what’s a safe pressure to do this test at.

Thanks for any help or suggestions.

2

Completely normal. Nothing is completely water tight. I often have to top off every year or two.

2 Likes
3

The max pressure for the cooling system is 16 PSI. So that’s what the system is pressurized too to test for leaks.

But what you might be seeing is after you did the drain and refill, is the result of air that was trapped in the cooling system.

I’d watch the coolant level for a while and see if the level continues to drop after you refilled it.

Tester

4

16 psi should be the operating pressure…

Check and or just replace the radiator cap…

5

Thanks all for the help. I’ll keep an eye on the coolant level. Can I ask, how did you find the operating pressure of 16 psi? Searching through ShopKey “coolant pressure” and “radiator pressure” I couldn’t find it. Is this specification listed under something different, the 16 psi?

6

Do folks in this century still use these:

41pMjc+t0KL._AC_.jpg (351×473)

To check the condition of their coolant/antifreeze?

7

I went to Rock Auto and looked up the pressure cap for your vehicle, and all showed a spec of 16 PSI.

Tester

1 Like
8

:rofl: I did the exact same thing…

Then I did a little googling to confirm…

I still have one I think, and the floaty ball one…

My older buddy had a Antifreeze Refractometer back in the day…

image
image737×629 57.8 KB

2 Likes
9

Tester

10

Wow!

Anyone with a mulitimeter can do that.

  1. is up to 0.5V reading ok, to allow for meter error?

  2. Engine/coolant hot or cold when taking this reading?

11

I’ve owned a couple of cars that would not maintain Full coolant level in the overflow tank, and I never did figure where the excess went. I didn’t keep adding to it though, just settled for a constant Low reading.

12

I think as long as what’s in the overflow tank is somewhere between the Min. and Max. marks, when cold, all is fine.

1 Like
13

Agree with other responses on this being a non-issue.

Remember that what you’re seeing is only the “overflow” in the reservoir. The radiator itself is likely full and just fine, if there’s overflow in the reservoir. That level will vary over time due to a variety of factors.

Worry about something else. :slightly_smiling_face:

1 Like