Hello,

After watching many Youtube videos (for CRV) and reading old forum posts about coolant change, Im a bit confused in determining if my coolant actually is low. The Overflow reservoir is nearly empty, but I read posts where people had an empty reservoir, and they went to refill it via the radiator cap, but almost no coolant was accepted because it was actually rather full.

1) Does this seem low or not possible to tell from pictures? https://imgur.com/a/b2OKowl
(Big O Tire topped off my coolant in Feb 2023, at 212k miles. Car is now at 219k mile.
I have not noticed any leaks, so there should be plenty left i would think?)


2) If it is low, the Manual says that a change uses 1.3 gallons. But the coolant only comes in 1 gallon containers. With just 1 gallon, Would it be better to not drain, and just top off?
I would hate to buy a second jug just for the other .3 gallons, when I'm never going to use the rest because I'm getting rid of the car in the spring.
There is also some turorials syaing to just top off via the overflow reservoir instead of the raditor cap, idk whats best.

thanks
2007 CRV 2wd ex-L

 

The cooling system works under pressure, and as the temperature goes up; so does the pressure. The radiator cap usually has a set built in relief valve that vents coolant to the overflow tank.

However when the coolant temperature lowers, a vacuum forms and the coolant in the overflow tank should return to the radiator/cooling system. So the level may vary depending on when you look at the tank.

Basically, just top off the overflow tank to the minimum mark - unless you’re having overheating issues. Then you’d want to make sure coolant goes into the radiator.

 

Okay interesting. So maybe it's because the weather has gotten cold. I actually just pulled the reservoir tank physically out this time, and it's completely empty.
But when I open up the radiator cap, there's still blue liquid in it.( Although it is below the filler neck level that I think it's supposed to be at) but I'm not noticing any overheating issues so maybe it's just the cold weather. Ill just do a top off of the reservior tank then instead of filling via the radiator cap.

 

Top off the reservoir. Monitor, could be you're loosing coolant. It's gonna go higher and lower. Check and adjust when cold, look at it after driving to be sure it's not pushing it out the cap.

 

Yes, top off the coolant. Fill it to the max line. Air may have been trapped in the cooling system and the air may have got purged out, in which coolant from the reservoir cycled into the radiator and engine.

 

Okay thanks. Will top off the reservoir

Also, I know everyone swears by using type 2 Honda OEM coolant only, so it might be sacrilegious to even ask. But since it's just a top off and I'm getting rid of the car in a few months, do you think it matters if I use this universal coolant one by O'Reilly? as it's half the cost
https://www.oreillyauto.com/detail/c...=coolant&pos=0

it's not blue but I'm not sure how much the color matters these days. It is silicate free and all that. says universal. I know it's already been topped off by Big O Tire previously with some non OEM coolant they use-"service pro universal 50/50"

 

You can use the universal coolant since you don't know what kind of coolant was used at Big O Tire. However, depending on the miles, I'd recommend a flush, then put the blue coolant in.