So about a week ago i noticed that the warm air coming out of the air vents in my 99 Accord was just warm. Previously it was hot enough to make me have to open a window slightly. (its about 15 degrees outside).

Anyway, so now the air is only getting warm and not getting hot like it was. I do park in a garage all night so its not completely frozen to the bone when i get in. Also i noticed that even after driving for a long time with the heat on, it still is just warm. Any ideas as to the problem? A buddy told me that it could be the thermostat, but I'm not so sure. My dad thought it might just take a longer time because all the air ducts and vents are cold when i first get in.
Any input?

Have you checked your coolant level?
Bled the coolant lines to get rid of air bubbles?
Tested your thermostat?

I'd start there.

yea make sure your thermostat is not staying open or your engine isn't running alittle cold


me an been both have been through all the over heating and everything haha

Lol Yeah, cburns, we have. If your thermostat is sticking open, it will take what seems like forever to heat up. But it just sticking open doesn't mean you eventually won't get hot air, you will.

If you're low on coolant, I'd check all your lines to see if they're leaking. And see if they're firm and rubbery or kind of smooshy.

smooshy? haha well good way to put it

Lol yeah he'll know what I mean. It's when your hoses are going bad, they feel different. Like they start cracking and get...well..smooshy. Haha

OP, get back to us and let us know what's up.

I never thought about checking those levels. Ill do that after I get out of school today. I don't think the thermostat is bad simply because the engine temp hasn't changed much at all. It still warms up like normal and maintains that temp the whole time. My prediction right now is that the coolant level is low. Ill check it out and. Keep you posted! Thanks for the help so far!

So i checked all the levels today and everything seems fine. The coolant level was at max, both while the engine was cold and while the engine was warm. The weird thing is that yesterday it started pumping out warm air again. So now I'm quite confused. The only thing i did was change the setting from using outside air to circulating inside air. After that it got much warmer. Then i switched it back to how it was when cold air was coming out and it still continued with the hot air. So I'm guessing it was just a fluke thing that is done with now. Thanks for the help though guys!

Have you bled the coolant lines yet? I'd do that just for the hell of it. It could have a huuuugeee air bubble in it or something.

Cody's civic had that one night. It wasn't overheating or anything, it was running normal, but there wasn't any heat anymore. So he just floored it in third gear, got the air bubble to move, and we had heat again.

Yeah i guess ill try that, any tips on doing that?

On bleeding the coolant lines?

You probably have a bleeder screw somewhere, but Idk where it is, nor how to use it. I'll just tell you the way I know how to do it.

1) Do not start the car! Let it sit over night.
2) Take the radiator cap off.
3) Start the car
4) Let the car get up to normal operating temperature. (When the radiator fan comes on.)
5) From the engine bay, rev the engine up to approximately 3,000 RPM's. You can go higher, but I've never needed to. Just don't redline it. Lol
6) Watch the bubbles come out of the filler neck on the radiator. Every time the fan comes on, you should rev it higher. For some reason every time the fan comes on, it sucks in more coolant. So rev it a little higher.
7) Add 50/50 mix of coolant and distilled water every time it goes below the filler neck. Don't worry if any coolant spews out of the filler neck, it's bound to happen.
8) Keep revving, and adding coolant for about 30 minutes. Just a rough estimate, but if your engine has tons of air bubbles, it may take longer. Just look for when there aren't nearly as many air bubbles coming out, then you can probably call it quits.
9) Shut off the engine.
10) Put the radiator cap back on.

Even though you got your heat back (mysteriously), now you've bled your coolant system.

So now that I'm back to using the internet, and I have finally found time to update this thread. I found out the reason that my car wasn't getting warm was because of the nob that adjusts warm and cool was broken on the inside. Although i had the nob turned all the way toward the heat side, it was still turned partially to the cool side.
It was something that I completely overlooked. Who would have thought that could have been it?!?

*Fix*
Some quick-set epoxy and an hour or glue time.
It works like a champ again!