It is probably the catalytic converter. They get extremely hot during normal driving and even hotter when you have gotten on it a little bit. It is quite normal as they use the heat to cut emissions. If this isn't it I have no idea!!

 

same thing happens to my ss\sc

 

I have never heard that sound but I do get some clicking noise form the emergance brake when I get in the car or have just stoped and set it. It might be that the rear brakes slip a little when stoped? Also since the cobalts are a closed loop gas feed then the fuel pump might be releasing presure? Also check your spair tier and battery? There should realy be noghting hounting a new car anyway.

 

Well, at least they get to drive around in a nice car!!!!! But seriously, I haven't noticed any sound that was that loud. I hear the exhaust pipes cooling down on my car but that's a definately identifiable sound. Did you guys hear it right from day 1 or after a few months of driving? Could it be the muffler?.................lotsa people having trouble with those original ones. I even had mine changed because of baffles coming loose.

 

Ohhhh, I get what you're trying to say author...yea, I get a noise too from my rear passenger side too. Sound slike someone knocking on the interior plastic. But my car usually does it after I gover a speed bump or make a sharp turn. It's not exhaust....it's really weird.

 

It's more than likely the Fuel pump. Let's use common sense here, when you turn your car on the fuel pump gets turned on. When you turn your car off it's the fuel pump turning itself off.....seeing as the gas door is where you are all describing where the sound is coming from the fuel pump is USUALLY in that general area It's a common thing in the cobalts, mine has done it since I owned it

 

Well the thing is, it happens while the car is on. Like after driving for a while.

 

not too familiar with the exhaust setups on these cars, but a friend of mine had a pos plymoth lazer and he had the same exact "GHOST NOISE" lol....which ended up being a shitty exhaust hanger that was rather limp and every time he would stop, the muffler would bounce and tap the bottom of his car causing that "tap-tap-tap" sound..

 

I hear that frequently on my SS/SC when i'm parking my car....

Last day the passenger asked me... Hey do you have somebody in the trunk?!?!?


..... it's very very VERY bizarre...

 

i notice the same thing.... i got a base model 05 so it cant be the power windows or locks.... first time i heard it i turned off my road and was sitting at a red light and i heard it and looked back and saw a guy on a motorcycle and got kinda pissed thinking he was touching my car... but he was too far away lol

 

Actually guys I heard it could be the rear brakes adjusting... anyone ever notice the wires (not brake line, or parking-brake cable) , but the wire going to the back brakes? my 2.2L car normally/usually makes the noise after I shut it off and pull the parking brake...then it happens a good 30-60 seconds later... is it possible the rear brakes are electronically adjusted?? wheres Maven been these days? lol its def. not exaust... as thats more of a ping! noise... or pwr windows/locks...


-Brandon
2.2L Coupe silver

 

ive only had it happen once, and i kno for a fact its not the exhuast, cuz i know what the exhuast sounds liek cooling off, and i hear that, which is totally normal...just cant figure out what it wass

 

I to have experienced the "illusive noise" and for atleast a couple days i thought my antenna was loose and shaking whenever i stopped.... ya....not the case..! so i am to left to ponder what the hell it could be...the fuel pump theory sounds pretty darn good though...i was thinking that myself...maybe it cycles or something...?




___________________________

05 Black SS - Red Inserts **Airbox Mod**
Waiting to be Staged......1 2.....

 

SOB so wtf is this noise!!!!! it freaks me out! i here it alot now haha

"you know you drive a cobalt when your passenger asks if someones in the trunk...tap tap tap tap" hahha

 

It's the ABS system check guys, my Chevy Astro used to do the same thing, don't worry its normal!

 

its your exhaust gettign to hot!!! and cooling down us redline guys have had this problem for a long time once you change the stocker it will go away

 

Tap noise is normal! You only hear the noise, (tap,tap,tap), shortly after start up or just after the cars turned off. The noise is from a soliniod in the EVAP system. The PCM tests the system at these times and when you have 15% to 85% fuel in your tank. Don't go crazy over it or take it in to get fixed, there is nothing wrong.

 

I love how everyone has said it is something completely different

 

You can really only guess by what the person has reported the noise to be... if it's a double click coming from the back end after you turn the car off it's most likely the ABS Diagnostic system doing it's thing... a random ticking sound is from the exhaust (that's a little obvious)

 

he he he damnnear everyone with a cobalt weither it be base up to SS says they have the same noise. Dealer says they are not sure eithor. So as long as the tires don't fall off or the brakes quit stopping, I say Fuc it But if anyone does know why please let me know.

 

Mine does it all the time after shutting off. The first couple of times I almost opened the trunk to see who was in there making that noise!

...and my base '05 coupe does not have ABS.

 

this happinns all the time in my moms equinox too

 

mine the same ....

 

That is CRAZY that I read this posting. So I'm waiting at Wendy's drive thru and I swear somebody was knocking on the side of the car or on the small window behind me.

Strange

Mark

Vancouver B.C

 

There's another thread on this topic already. I think it was diagnosed as the car checking it's trunk latch and other system tests.

Anyhow this is normal so let the ghosts be. I have a 2.4 SS and it does it as well.