Coolant doesn't drain as much as stated

Sorry to ask such a simple question but I don’t know where I could get this kind of info. I drained my coolant through that plastic plug under the radiator area and according to my manual it is supposed to be 1.4gallons but mine only drains 1 gallon. I was curious if there is something I might need to worry about.

It is 8gen civic radiator is topped off and bled of air including heater core.

What’s an 8gen? Never heard of that model.

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I suspect OP means 8th generation.
I would like have years posted rather than generations.


The balance of the coolant is in the engine caught behind the closed thermostat


+1 and as long as you’ve been changing your coolant on time I wouldn’t be too worried about the little bit left behind.


Exactly ! things change mid generation even mid year. I know when people ask what year I am I don’t tell them I’m 156th generation.


There’s still going to be quite a bit of coolant left in the engine block/passages, unless you flush the system a couple times, you’re not going to get every bit of old coolant out.


Gregory I became Pope in 590, what generation of Gregories would that make me?

There’s some coolant left in the engine block.

To drain the engine block, the drain plug is removed.




I see thank you for the info but I should have been more clear. My manual exactly states 1.4 coolant should come out for change and 1.77gal is in the system total. Reservoir is not that big it is pretty small too. It is 09 civic if matters but there was no realy changes for 8th gen so I didnt say it cause doesnt matter for this car.

Be sure to have the heater set on Hot. That opens a valve between the engine and the heater core.

On my 1999 Civic, I just drain the radiator and refill with water, then drive a little, let it cool, and drain the water. Whatever’s left behind is mostly water. Then I put in 1/2 the system’s capacity of full strength coolant and top up with water. Then I mix up a quart or so of 50-50 mix for topping up after a couple drives and cooldowns.

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For your original question “is this something I should be concerned about”, I’d say no, as long as the cooling system is now full and bled with the correct 50/50 mix of coolant and water.

How do you know exactly how much coolant came out? By measuring what you put back in? If so, make sure there are no air pockets in the cooling system.

When you drain hte block also, there will still be some coolant left behind. Draining the block should get you to the 1.4 gallons you are looking for.

If your coolant was still clear and not cloudy, I would strongly recommend that you do NOT flush out the little bit remaining. It wont do any harm. Flushing is more likely to harm the engine as you get more contaminants in the system that way.

Just premix the coolant in clean jugs or buy premix and refill. You will be good for at least another 5 years that way.