Losing coolant

Hi all, I’m having trouble with my '96 Civic EX. The car has 205,000 miles on it. I blew out coolant hoses earlier in the year and had them all replaced, along with the thermostat. In the last few weeks, I’ve had to add coolant about every three to four days. It doesn’t seem to be leaking when it’s parked (no puddles in my parking spot).

The temperature will climb (sometimes alarmingly) at stoplights, then drop again when I start moving. I’ll check the coolant volume, and find it’s low. Add coolant, it runs OK for a couple of days, then repeat.

It’s also hesitating and running roughly at startup. No white smoke, and the oil doesn’t seem to be contaminated with water. Nonetheless, I’m worried about a cracked gasket or head, and want to get some opinions on what it might be (including, confirmation of my fears if they’re likely).

First time post- thanks ahead of time!

Replace your radiator cap for starters. It’s probably old and weak, allowing coolant to escape when the system is under pressure.

Check your oil. Does it look normal or like a chocolate milkshake?

Then check the operation of the cooling fans. Heating up at stop lights is a sign of inoperative fans.

You might also want to bleed the system and make sure there are no air pockets. Air in the cooling system is not good.

How far did you drive the car when you “blew out coolant hoses” earler this year. Did the car overheat then??? After you replaced the hoses, did you have a pressure test done on the system?

You could have a blown head gasket as a result of overheating when you blew the hoses. A pressure test will reveal this quickly.

Replacing the radiator cap will not solve the “alarming” temperatue climb.

I strongly suggest a pressure leakdown test before proceeding further. it’s a simple test done one cylinder at a time wherein you orient the crank such that both valves are closed, remove the spark plugs, and see if the cylinder will hold air pressure. If it will not, you have a nlown headgasket. You can buy a kit cheaply at any parts store and follow the instructions. One a Civic it’s easy to perform.

The chronic overheating combined with the loss of fluid without driveway puddles and the rough idling and rough startup all combine to make a headgasket leak a good possibility. White smoke won’t always be obvious because it’ll happen primarily on deceleration when the cylinder vacuum spikes and it’ll dissipate rapidly behind the tailpipe.

Oil looks normal. No sign of water in it, so far as I can tell.