well, I just joined this group today so sorry if i dont have proper forum etiquette. Or my spelling.
I just bought a one owner 03 grand marquis with 65k miles. I got it at a lincoln dealer and it was a little old folk trade in. I have only had it since monday.......4 days. Today it was raining very hard out here in Georgia and so I had the a/c on low, had sirius radio on as well and after driving about 7 miles, i parked at a store. I did not turn the radio or a/c off just ignition when i stopped and parked. For the first time, I heard a clicking noise under the right side of the dash/firewall area. I have had the a/c on before and dont seem to have noticed this. Would anyone have a clue as to what this might be? I know there is a previous post about a dash clicking but I have a different year model and it isn't doing quite the same as other poster. Any help would be great.

Craig in Marietta

 

what kind of clicking sound? like tapping on metal or plastic?

 

if i had to guess, it is like a light tapping on plastic. not like a fan blade sound but something else. not sure how else to describe it. after i turned off car and sat there on my cell phone chatting, i heard it and when i stuck my head down on pass side floor area it was a clicking that lasted about a minute or so. (seemed longer) since i have had the car (4 days) i only had a/c on. when the guy at best buy had to test everything in the car to make sure it worked, he tried defrost, a/c, heat, bi level and such. so would that have anything to do with it? it didn't do it before i had my sirius thing installed.

 

well, i just went out to the carport and started car and i tried all the settings on the heat and a/c system. i then turned it off and no noise. i did it again and left system on when turning engine off like when it happened earlier today and it didnt do it. perhaps it was a one time thing resetting itself or something. i will give her a big drive tomorrow and then test it again to see if it happens. thanks man.

 

yup, I'm stumped. If it doesn't do it with a quick turn on and off... drive it around a while and when you stop, pop the hood when you turn it off and see if you can hear it from under the hood better or under the car, or the passenger area like before. It may just be thermal expansion of something. I've never noticed that on anything myself (other than metal heat shields that give that tinny tap tap noise).

 

ok, here we go. I am part blonde so please understand.

After I drove the car for a bit, I turned car off with the a/c in normal mode, then vent and then in the off position. The noise as I got closer to the pass side is not really a tapping, it sound like a bumble bee is stuck somewhere. It is not the regular fan I dont think but it is a slight faint noise that is like a bumble bee and it is stopping in about 30-45 seconds. Can it just be a normal shut down of everything? I did just have the fan on the lowest setting, so maybe it is normal as it is stopping everytime. Do you think I am reading too much into it? thanks for all your help, i appreciate it.

 

it could be something rubbing on the squirrel cage that is the blower/fan for the AC system. It could also be a bearing with a flat spot in the same fan. I would be surprised with either one since I've never known the fan to spin for that long after being turned off, but then I've never inspected these blowers to see how long they actually spin. If the sound slows down until it stops, I would say it's to do with the blower somehow. if the sound does not slow down, it may be something else (though I can't think what that might be at the moment).

 

slymer,
well i figured it out. i opened the hood, let the a/c run for a bit and then turned the car off. I ran around to listen to that "buzzing" sound and sure enough, I found it. The bottom a/c line that drips all the water on the ground, it was simply "buzzing". All I did was put my finger on it and it stopped. I let go, and it started again. I tried to move it just slightly as it is supported by some metal bracket and that seemed to do the trick. So go figure huh?

 

heh... go figure. see if you can tighten the metal bracket down to whatever it's bolted to. if it's loose, it'll start buzzing again. Otherwise you might want to get a screw down type cable clamp that's the size of that line (or maybe a zip tie) and tack it down somewhere if you can.

 

Just for further reference, it's not at all productive to keep the a/c on without the engine running. Without the compressor cycling on and off, it will only blow what ever cold air that is left. Which is not much at all. After that it's just premature battery drainage. You should leave the engine running for a/c and always turn the key backwards if just for the radio only. Plus, some would argue that it wastes more gas to shut off and restart the engine then to leave it idling. I'm not too sure about that one. But I guess it all really depends how long the engine is off for. Glad you fugured out the problem. Good job.