Gurgling noise from behind dash

[Civics Rule]

Hello everyone....
I'm brand new to this forum, so please forgive me if I'm not in the right place.
I have a 2001 Civic LX with 82000 miles and I'm hearing a "gurgling" sound coming from behind the dash. I'm guessing it is air trapped in the coolant in the heater core. I had a new timing belt and water pump put in last summer, and since then I have heard the same noise one other time. That particular time I put the front of the car on ramps and removed the radiator cap and let the engine run for at least a half hour with the temperature control turned to "hot" and the fan on. At that time I did notice some air bubbles come out of the top of the radiator and it seemed to have taken care of the gurgling sound. Well, now it's back again and I tried the same fix, and a couple of air bubbles did come out, but the gurgling sound is still there!!!!!!!
Does anybody know how to get rid of this noise or is it something that I should not be concerned about. I do have plenty of heat coming out of the heater vents inside the car, and the coolant level has not gone down since I had the timing belt and water pump replaced. And the temperature gauge has always stayed in the same position once it warms up.
Thanks for any info or help!!!!!!!!

 

[pyropunker25]

might be a small leak in your head gasket? i had a similar problem 2-3 weeks ago and i t was a pain in the ass...

 

[sr6000]

I just went had the head gasket problem with a tiny hole into the combustion chamber a few months ago. that very slowly sucked the coolant out to the point i had no heat at idle. How's your heat at idle compared to when you drive. If it starts to get cold perform a leak down test to see if there might be a problem, with the head gasket.

 

[clean02]

i hear the same noise in my civic too. i have not noticed a difference with the heat at idle.

 

[Civics Rule]

I'll check the heat at idle tomorrow and see what happens...... I think I'm also gonna put the car back on the ramps and take the radiator cap off and let it run for awhile and see what happens (maybe I'll get some more air out). This time I'm gonna just let it idle and not rev the engine. I read somewhere on the internet that I shouldn't have revved the engine when performing this task, for some reason or another. I also thought the time I did this last summer, that when I turned the temp control to cool setting, that I couldn't hear the "gurgling" noise, but now I hear it whether it is set to hot or cold.
Thanks for the input guys..... and how do you perform a leak down test?

 

[Renzo21]

It is definately not a head gasket problem or a cracked head. You said you are not losing coolant there for coolant cannot be leaking through the gasket into the combustion chamber. If you want to take the test anyway just go to an auto parts store and ask if they have any fluid to check for bad head gasket. I forget the name of the one the shop I work at uses (I just use is, I don't read the labels, heh). Anyway, also you will need a special tube that you put some of that fluid in. You stick the tube onto where the cap of the coolant reservoir goes after the car warms up. If the blue fluid turns to a greenish yellow or a yellow then you have a head gasket problem. This works by the chemical reaction between the fluid in the tube and exhaust fumes. If there is a leak in the head or head gasket, exhaust will leak into the coolant and escape at the coolant reservoir. It is a two way leak... But just for that gurgling noise, I would just let it be and not worry about it or drain the coolant and refill it. Who knows, it would be easier to tell if I could hear it.

 

[Mr. Jollypants]

Don't worry, it's just the little Hamster under the dash running the generator to keep your dash on with electricity. Sometimes he drinks too much water or he could be brushing his teeth.

Sounds like your coolant is boiling. Air is getting into your system somewhere, I'd check around your head and freeze plugs.

Does the temperature gauge ever jump randomly? Or rise then fall?

 

[Civics Rule]

Well, I just got done with the Civic again. I put it up on ramps and took the radiator cap off and let it run until the fans kicked on. I did notice a few more bubbles, but nothing real significant. And as the coolant in the neck of the radiator kept creeping up as the engine ran, I used a radiator fluid tester to suck the fluid out of radiator neck as it got higher. Then when the fan kicked on, the fluid level would drop back down and I would add a little bit to top it off and repeated this process until I the fan had kicked on three separate times. And the "gurgling" noise is still there!!! (Damn it!!!) I also checked the heat coming out of the heater vents with the fan on at its highest setting. I couldn't tell the difference between the temperature at the vents when driving or when parked with the engine just idling. So I'm guessing this is a good sign (I hope). I'll just keep an eye on the coolant level in the overflow tank and make sure it stays between the upper and lower marks, it has for the past ten months or so. I just wish I could figure out a way to get rid of that damn gurgling sound!!! Oh well...... Also: I kept and eye on the temperature gauge and it remained at the same position after it reached temperature.

 

[Civics Rule]

I'm starting to believe that the letter "H" that is on the grill of my Civic, doesn't stand for Honda..... it stands for HELL!!!!

 

[civiclx]

i have the same problem too!!

 

[bones420]

it could be the thermostat, my old whip use to do that after i drove for a while and turned off.
it sounds like boiling water behind the glove compartment. if u hear it again raise your hood and see if your reservoir is bubbling

 

[civiclx]

for me if i hold the left air vent it would stop making the noise but i don't know what the is problem yet ? but even if my heater is on or off it would still make the noise

 

[civiclx]

?

 

[Civics Rule]

I stopped at a Honda dealer the other day and asked to have a tech listen to the gurgling noise. The tech could also hear the noise, but said it was nothing to worry about and it wasn't nothing out of the ordinary. So I guess I'll just keep an eye on the coolant in the expansion tank and hope for the best......

 

[civiclx]

can't drive with this noise