Red/green engine coolant

I noticed that my engine coolant liquid is right at the minimum mark even though I only have 7000 miles on the car so far. I bought a gallon of antifreeze/coolant at Autozone. To my surprise, when I opened it the liquid is red!

I did some quick googling and I see that I am not supposed to mix red coolant with green/blue (which is what my car has). What should I do? Flush the coolant in my car then replace with the red stuff or just give away the red stuff and rebuy the coolant that Honda recommends? My first car. Know very little about maintenance.

The brand I got is Peak.

I’d go to your Honda dealer and buy a gallon. More expensive, but no questions about compatibility.


Before you do anything else, look in the owner’s manual and see what the antifreeze is. They might have a Honda brand name, but you can do a web search to determine what the basic chemicals are. It will be something like ethylene glycol or propylene glycol. There are other chemicals used, too. Then read the label of the Peak coolant to see what is in it. If they don’t list it, you can get the Safety Data Sheet for it on line. You can do the same for the Honda coolan, for that matter. If they aren’t the same basic constituents, return the Peak and buy a compatible coolant. It’s a lot easier if you buy the coolant at the Honda dealer, but it will be more expensive.

The red coolant usually refers to a GM coolant, DexCool. I doubt the Honda uses DexCool. The glycol based coolants aren’t compatible with DexCool, and you shouldn’t mix them.

We are dealing with a person with limited vehicle knowledge who did the right thing by checking to see if the solutions were compatible. Tester is correct, purchase the correct item at the Honda parts counter as this is a new vehicle still under warranty. The opened container can’t be returned.

Autozone does offer a blue coolant for Honda vehicles called Pentofrost A3 but it will probably be better for you to buy a gallon of OE coolant from a Honda dealer.

“Pentofrost A3 is a phosphates organic acid technology (phosphates oat); which is categorized as goat (hybrid organic acid technology) in the US market. Pentofrost A3 is suitable for all Asian vehicles using blue antifreeze/coolant.”

BTW, if the coolant level is at the minimum line in the reservoir the next time you have the oil changed, they will probably top it off with water.

Concur with the advice above. Honda engines are very particular about the coolant’s specs. If you are seeking a long lived car, best bet is to buy the coolant at a Honda dealership. I doubt costs only a little more than the coolant you bought at AZ. Ask the folks at Honda to show you which coolant is the right one for your particular engine. You could ask them while you are there if there are other aftermarket coolants that meets all of Honda’s coolant specs. Give the coolant you purchased to a neighbor, friend, coworker, relative etc, somebody who owns a car that can use that type.

Be cautious when using coolant in any open container. Animals, cats, dogs, other pets etc are attracted to its odor and will sometimes drink it. The result is often fatal.

Don’t take this the wrong way…
(Perhaps you could teach me something. :wink: )
Have you consulted the Owner’s Manual?

I’m not familiar with (none of my cars have that) a coolant reservoir marked “minimum” (and “maximum?) .”

All of my vehicles have markings that read “cold” and “hot.” The “cold” is actually a minimum mark, but it is the level at which the coolant should be set.

When a vehicle has been run at operating temperature it is considered to be “hot.” The coolant will expand and will flow under pressure into the coolant reservoir and will rise to around the “hot” mark. Lots of space is left in the reservoir for expanding, hot coolant.

Do you only have one mark?
Does the Owner’s Manual say to fill it higher than that when the engine is cold?

I’m thinking that perhaps the vehicle is properly set and does not need coolant added.

So, have a look in the book and teach me something new. :slight_smile:

Oh, and I agree, if anything is added make it the genuine Honda coolant that is required and understand first whether it is concentrated (needing to be diluted) or pre-mixed (already diluted).

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I just bought a gallon at the Acura dealer yesterday, for $20. I’ll bet you are supposed to use the Type 2 long life. I absolutely would not use anything else on a car with 7000 miles. Just get a gallon from the dealer. You wont need more than a couple cup fulls a year. The last gallon I had I bought in 2008 and still would have been good except it developed a leak in the container. So yeah throw the other stuff away and get the recommended. What does that compare to what you paid for the car?

@common_sense_answer makes a great point. You might not be low at all, read your manual. But still get a gallon at the Honda dealer, you’ll want to have it on hand.

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If this is a new vehicle with 7000 miles I would be wondering why the coolant level is low. Top it off and keep an eye on the level. If the level continues to drop take it to the dealer or an independent mechanic to have it checked.

Ed B.

No, don’t ‘top it off’. If it was at the ‘full cold’ mark (the lower mark) when the engine was cold, it’s right where it needs to be. The owners manual will make it clear what needs to be done.


While I agree it may not need fluid at all, I usually have had to add a cup or two after a few months on a new car and is fine for years after that. But yeah look at the full hot, full cold marks.

Thank you all for your thoughts. The liquid is definitely right at the minimum line when cold. I have been paying attention to the temperature gauge, and it sits right in the middle between Hot and Cold while I am driving so I think I am ok for now. No warning on the dashboard either so I was probably just being a bit paranoid. I will ask the dealer to check out the level the next time I get an oil change. I have offered to give away the red liquid to my friends, but no takers so far. Everyone I know has green color coolant.

I guess I will try to sell it on Craigslist.

Just take it to the recycling center. They’ll deal with it. Often they have left over paint etc. that they give to people free. Chalk it up to a $10 lesson. Just don’t deduct it from your taxes.

Selling the other coolant on CL is a good idea. If you get no takers you can post it in their “free” area, and somebody will come get it. I get rid of stuff I can’t use that way, not much hassle involved. One time I got a bunch of free stuff using CL, picked it up, took it home, decided I didn’t want it, and got rid of it the same way, all in the course of a week … lol …

re the fill level: The coolant in the plastic reserve bottle should be near the minimum line when the engine is cold, that’s the correct fill. There’s quite a bit of lee-way though, doesn’t have to be right on that line. As long as the radiator is full, that’s actually all that matters. There doesn’t need to be any coolant in the reserve bottle for the cooling system to still be working at 100% efficiency. I had a problem with the reserve bottle leaking on my Corolla one time so I ran with no coolant showing in the bottle at all for 6 months or so and never had a problem, just checked the radiator is full once in a while is all.

Hey, that’s good! I’m proud of you! If more people were just a little bit “paranoid” or rather conscientious about maintaining their vehicles then fewer people would be facing automotive catastrophes! I am that way too with a new vehicle. Better “paranoid” than “duh, no clue!”

Good idea to ask to have it checked and good observation by checking gauges. You’ll soon learn the nuances of this vehicle and you’ll have a long affinity for each other. Then you’ll relax and just have a peak at vital fluids once a week to be sure everything is copasetic. That’s good protection. :smile:

Good job!

It’s just a gallon of antifreeze. One thing I have done when I changed cars and had extra filters on hand is just gave them to the shop I use. I also have poured brand new oil into the recycling barrel because I couldn’t use it anymore. Yeah its too bad but that’s how you deal with stuff that’s obsolete.

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Give it to a buddy with a chainsaw…mixed with some paint thinner, it’s great bar & chain oil.

…or give it to a friend who heats with oil. This is what most “recycled” oil gets turned into, anyway: fuel oil.

Also, oil makes a good rustproofer, but I favor bar and chain oil, as the “tackifier” additives keep it in place longer.