I own a 1998 honda civic ex sedan automatic with 180,700 miles on it completely stock. Lately I have been having to fill up my coolant reservoir every 3 days as it appears to be bone dry, I was stuck in traffic a few days ago in the snow and noticed my temp gauge was 3/4 high but when I put the car in park and released the brake it started to go back down to normal and once I got home I checked my coolant and it looked empty so I filled it up. I am not leaking coolant I have checked under my car a bunch of times, I do not have an insane amount of white smoke coming from the exhaust, I didn't see any signs of coolant mixing with the oil or oil mixing with the coolant, the radiator fan does turn on a few minutes after start up. I have been noticing what looks like steam coming up from the steering wheel whenever I have the defrost and or heat on so haven't been turning those on lately. I added coolant yesterday and topped off the radiator and when I squeezed the hose that goes from the reservoir to the radiator I did notice some tiny bubbles coming out of the radiator end.

any help will be much appreciated.

I do have a check engine light on due to the idle air control which will be getting repaired by the weekend.

 

white smoke = coolant burning

 

YOU NEED A NEW HEAD GASKET

 

Your coolant loss is through the heater core. This requires taking the dash out.

Nothing else in your post is indiciative of any other major coolant loss areas. It's still cold out so you should still see some steam from the exhaust.

If you are worried about the head gasket possible cause, rent/buy a block tester and check for exhaust fumes coming from the radiator.

I tend to believe it's just your heater core though from what you described.

Topping up your coolant consistently should keep the car from overheating, now that your coolant has gone down enough for an overheat, you will need to burp the system and continually top up after that until you get that heater core fixed.

 

Thank you TomCat39 for your reply so you're thinking I'm loosing my coolant through my heater core correct?. That actually sounds right to me I am smelling coolant while driving when I see the white steam and I only have the normal amount of steam coming out of the exhaust and it doesn't smell like coolant. I am gonna have my mechanic check it out for me when he puts my new ivac in the car this weekend. I've researched signs of a bad head gasket and I'm not seeing any signs that I have a bad one.

How do I burp the system?.

 

98 civic? You park on a hill with the nose of the car pointed up, let it cool enough that it's safe to pop the radiator cap (doesn't burn to touch the cap). Pop the rad cap off then start the car and put your heater temperature setting to max (don't have to turn the fan on) and let her warm up until the radiator fan(s) kick on twice. Shut the car off and see if you need to top up the Radiator, top up if needed. Close your radiator cap then top up your coolant recovery bottle to max mark. Then check your recovery bottle every day and probably will need a little top up daily until you get that heater core fixed. I think the manual says to pop the cap to the first lock position but most people just take it right off. Some coolant may come out while doing it and on cold days it can take a good 20 minutes for the fans to kick on.

Yeah, smelling coolant in the cabin is another dead give away that your heater core is leaking. Just don't try the "stop leak" pellets, they have a tendency to clog up radiators and heater cores causing even worse issues, just best to replace when they leak.

Addendum:Because your core is leaking, I would put your cabin temperature control to cold after burping the car. I would probably leave it on cold until you get it fixed. Also if when you are burping the car you can feel wet floors down by your gas pedal, just put temp control to cold and leave it there for the rest of the burp process. After just leave your air on cold until you get it fixed. Hopefully your winter is near over and it's not too viciously cold before you get it fixed. Not too sure just how bad it's leaking. I'm hoping the flow control valve on the temp control fully shuts off the flow of coolant to the core. If it does then the air can't get to the rest of the system while temp control is on cold and it will stop your coolant loss in the meantime.

 

heater core, no dounbt, had the same problem

 

The fastest check would be to set the temperature to cold, for the 3 days it takes to lose coolant. Check the coolant in the overflow tank,and if it hasn't gone down, you have isolated the heater core as the first possible problem.

 

What if its the heater hoses? All that work to replace a heater core and it turned out to be just the hoses. Did OP pull up the carpet to confirm any coolant inside the car?

OP get under the car and pinpoint the leak. You said you see steam rising from the steering wheel, doesn't make sense. Either heater hoses, coolant hose running to the throttlebody thats under the intake manifold or the water log o-rings are gone.

 

I believe all the rubber for the heater coolant exchange is on the engine side of the firewall. Either way once you get to the heater core you will see any hose and replace them being that's the only way to get to them. The steam from the stearing wheel does make sense because of the way the air flow goes. Blower is by the glove box and the air is pushed towards the driver and goes up to the windshield by the drivers legs. And all the things you mentioned would not account for steaming up the window when you use "defrost" but fits the heater core.

The heater core metal hoses stick through the firewall just like the AC condensor metal hoses do. Then the rubber connects to them on the engine side of the wall.

There is no doubt it's the heater core. Please see the images below. Please note the firewall grommet and the heater core metal hoses that go through the firewall grommet. I have highlighted them for you.




So taking all that into account, it can't be the rubber on the engine bay side due to fogging windshield anytime the heater is on defrost and the temp is not on cold. All the while smelling coolant inside the car while driving any speed down the road.

 

But the carpet should be damp in that area, I'm not even sure if he meant steam coming up outside the windshield or inside the windshield. I could be coolant dripping onto the exhaust manifold.

 

The carpet could be wet and Daisy didn't know to check it. Then again the fluid could be evaporating or going under the sound dampening material that's under the rug, keeping the carpet dry.

The biggest give away is the steam is noticed only when the heater is on and also with the defrost. Unless there was one heck of a hole in the firewall, steam from the coolant wouldn't get into the cabin from the engine bay. And the other key piece is smelling coolant while driving when you see the steam, all inside the cabin of the car. If it was outside of the car you should only catch a hint of coolant smell when sitting idle so it can roll up to the fresh air intake. I bet in this case it doesn't matter if it's fresh air or recycled air, the smell of coolant and steam would be there when the heat is on.

Like I said, looking at all the factors together, it points at a bad heater core.

Daisy can take a look at the hoses on the backside of the motor to see if there is any blue-greenish-white residue on any hoses or the firewall but I suspect none will be found. The leak appears to be inside the car.

 

Thank you for all the replies. I am a girl just don't know much about cars but am learning from all of you. I checked my rugs and they were dry. I only see steam coming from inside the car I didn't use the defrost or heat at all today so didn't see any steam. I believe TomCat39 is correct about my heater core gonna get a price for that job from my mechanic this weekend.

Thank you TomCat39 for the detailed instructions on how to burp the system sounds simple enough I will do that and will also try the setting the temp to cold air instead of leaving it on hot and see what that does.

 

You coolant might burn a little due to the age of the motor, check for leaks daily from the radiator and check your fluids level regurlarly is my best advice. Do the maintenance on your car.