My accord has 207,000 miles and is it common to refill the resevoir once a month or is there something to investigate further. I do not see puddles of coolant on the floor and I have change all the tubes. I also open the radiator cap and the coolant is where is its suppose to be.
There is something to investigate further. You should not be using that much coolant and the reason needs to be found. Any decent shop should be able to diagnose this without too much difficulty. The first step will probably be a visual inspection to include the area below the water pump, followed by (if necessary) a cooling system pressure test, perhaps followed by checks for evidence of a headgasket breech.
The first thing to try if it hasn’t already been done is replace the radiator cap.
If the radiator cap is opening lower than it’s rated pressure or what is called weak, it will allow the coolant to escape as a gas. Then you fill the coolant reservoir every month.
Remove the oil filler cap and look both at the underside if it, and with a flashlight (if required) down into the motor.
Everything should be nice and dark - color of used oil. If you find any light brown deposits (like creamed coffee froth), then there’s a leak internally somewhere.
We hope not, but it’s a quick easy check.
If the above, and these are all negative, the remove the spark plugs and check those. They should be tan in color. If coolant gets in there, they’ll be much more colorful.
Hopefully it’s just a cap, and that’s a nice quick, easy fix. Keep these in mind if the replacement cap doesn’t solve the problem, and after you do TSMB’s checks.