What is the point of changing coolant if it get's constantly replaced?
 

Based on the maintenance schedule of the coolant:

1st replacement interval is 11 years/137,500 miles (220,000 km).
2nd replacement interval is 6 years/ 75,000 miles (120,000 km) after the 1st.

...I don't really understand the point of replacing the coolant. Why would it need to get replaced if you're constantly replenishing it? Especially during a long period of 11 straight years, wouldn't it have been replaced several times over?

Edit 1: When did I ever say it was being replaced constantly? I said "constantly replenishing". Constant could be any frequency. The definition of constant means occurring continuously over a period of time. So let me be specific, "topping off when needed". Also my car is still relatively brand new, under 10k miles. There aren't any signs of leaks that I know of, so it's doubtful I have a leak.

What? How is it being replaced constantly? Unless you have a serious leak it would never happen.

Me thinks there is a piece of the puzzle missing.

Replacing (the entire coolant) vs topping off is NOT the same thing.

It's like saying "my car burns a quart of oil every month, every 6 months I have an oil change so I don't need to change my oil"

Wow kids theses days. Would not be surprised if he clams he's an engineer of some kind.

Any who, short answer, the coolant brakes down over time and it's not as effective.

Your Google-fu is weak young grasshopper

I'm new to the FRS, just got mine a month ago, but reading around here I've seen several people talk about these cars eating coolant. I can't say if mine does as I just got it. But I think the OP was sort of referring to that issue. If you're eating through and topping off the coolant at a higher rate than the scheduled interval then theoretically you've changed it a few times. Just speculating on what the OP was getting at. I'm not sure how widespread the coolant eating problem is or at what rate they are eating it.

But lets say it burns 1 quart a week. In 6 months you have put 24q in it. I used to have an Integra GSR that was hydrolocked and sat up for a holiday weekend waiting for an insurance adjuster to look at it. By the time he arrived it was dried out and would start. They screwed me over and didn't cover it. The damage on the cylinder walls was was so bad from those 3 days that even after boring to the service limit you could still see the damage. After a few years like that it would eat up the rings and burn at LEAST 1q per week.

I think the OP was kind of poking fun out of frustration that his car is using coolant.

This is news to me, If my car was eating coolant I would be a tad concerned. The engine cooling system is pretty much a closed loop. Topping it off every few months with a few ounces of coolant would not cause all of the coolant to be replaced, even after five years.

I'm willing to be corrected on this one but if my twin was eating coolant to that extend I would be checking for leaks and doing a coolant system pressure check. (Or getting the dealer to check it under the warranty).

See Edit #1.

But how often and how much are you having to add? It should go away if you aren't burning it or leaking it.

I have owned the car for 3 yrs now and I have only topped the coolant once myself (roughly .2liter) and once guys at Subaru dealership did during the oil change. BRZ has 7.2L of coolant (for manual car). I hardly doubt you will be "replenishing constantly" to add 7.2L of coolant in 11years. If you do have to add that much coolant, then you have bigger problems.


:bonk:

As pointed out, see the title of your own thread "What is the point of changing coolant if it get's constantly replaced?"

The point of replacing coolant is so that you replace the capability of it to 1) protect the cooling surfaces it contacts, and 2) continue to act as antifreeze. Additionally, since there is no filtration capability, replacing the coolant in its entirety means you can remove any contaminants that are suspended in it.

"Topping off when needed" is great if it was pure water and nothing else, except if you ran only water the insides of your engine block would soon lose the ability to transfer heat to the water. Aluminum blocks oxidize over time as well as iron blocks, and once this takes place you will find it increasingly difficult to run the engine cool, especially if you take it to the track or otherwise live in very hot/humid conditions.

The entire point of having to replace coolant is so it continually provides the ability to cool your engine over time. The reason why the interval becomes more frequent over time is because the manual is written assuming some corrosion with the stock block will happen, thus you need to increase the frequency you replace the fluids as mileage or time increases.

-alex

For sure don’t run pure water. Your water pump will be gone in no time at all. I live in Florida so the antifreeze aspect is rarely a concern. It’s the anticorrosion properties that are critical here.

Yup, it's why the manual is written the way it is, for people that don't understand how cars work.

Admit it, it is something we've wondered at one time or another, right? In my teens I had a friend who owned a Rambler. It burned about a quart of oil every 500 to 1000 miles. He decided there was no point in changing it since it was effectively changing itself every 5000 miles. In fact, we thought the car was better off because it always had 2 quarts in it that were less than 2000 miles old.

It ran like that for several years until some f&^kwit stole the thing and ruined our experiment. If memory serves, one of the Car Talk guys, Tommy, I think, did the same thing to a Dodge Dart. I don't recall how the car died, but it ran for a long time.

The key is that the consumption/replenish rate be high enough that the chemistry of the fluid is constantly being renewed. :D