radiator capacity

[moz374]

I'm working on flushing my radiator on the 03 Elantra (~105k mi). According to the owners manual the capacity should be 6.3 quarts, but it only took less than a gallon, 3 quarts at most, of distilled water before it seems to be full. Is that much volume in the engine block and just not filling because the thermostat is closed, or should I be worried that my radiator is partially plugged somewhere or something? Thanks!!

I guess I was only able to drain out about 3-4 quarts or so from the radiator plug and unhooking the lower hose, so it makes sense that's all that would go back in. Where's all the mystery coolant and how the heck do you get it outta there?

[Karrde]

That coolant will be in the block. Our cars do not have a block drain so you're stuck with doing multiple flushes to get all the old coolant out. You say you filled the system with distilled water only? You should be using a 50/50 water/antifreeze mix.

[blmqzjc]

I've done my 05 Elantra twice. As Karrde says, you have to do multiple flushes. I buy 2 or 3 gals of deionized water, and flush it till the fluid coming out is clear (or almost clear). Usually takes 3 or 4 flushes. After the final flush, and drain, there will still be around 3 qts of mostly water in the block. Then I add straight coolant to the radiator (about another 3 qts), drive around to mix it all up, and test the new mixture. It has always been about 50/50 after this. If too strong, just drain some out (and save for rainy day), and add water to weaken it. If too weak, drain some out (and discard), and add straight coolant to strengthen. Dont forget to add to the reservoir as well.

For those who have coolant flushes done at dealerships or other places, ALWAYS test the coolant after the service. I've never seen one done "too weak", but I've seen many where the coolant mixture was way too strong. My VW often came back 80% coolant, cause they were too lazy to adjust it down to the 60% level.