Alright, this strange occurance has happened to me a total of 4 times since I bought the cobalt. The first time it happened was at a red light. *tap*tap*tap* It sounded like somebody was knocking on my window. I look back to see but nobody was there. The next time I was outside of my girlfriend's house. *tap*tap*tap*tap* I jumped around, nobody again. Etc... etc.... This sound is almost exact to somebody knocking on the body or glass of my car. Has anybody else experienced this "Ghost?"

Alright, this strange occurance has happened to me a total of 4 times since I bought the cobalt. The first time it happened was at a red light. *tap*tap*tap* It sounded like somebody was knocking on my window. I look back to see but nobody was there. The next time I was outside of my girlfriend's house. *tap*tap*tap*tap* I jumped around, nobody again. Etc... etc.... This sound is almost exact to somebody knocking on the body or glass of my car. Has anybody else experienced this "Ghost?"


is it after your done driving within like 2 minutes? sounds like it coming from the right rear, if so I get it too.

Yes, I have the same noise. It sounds like it's coming from the left rear panel. I sit and let my engine warm up every morning and I hear this noise almost every morning. I have heard it a few times after I have turned the car off.

engine knock?

engine knock?

No. It's like someone tapping on the side of the car.

No. It's like someone tapping on the side of the car.
hmmm....my only other guess would be your power windows or locks. but that's very odd it would do that.

It also happens when the car is completely turned off. I've been trying to find out what it is but can't. It's like four taps.

It also happens when the car is completely turned off. I've been trying to find out what it is but can't. It's like four taps.
has anyone been brutaly murdered in your car? :lol:

nah, but serious that sounds very odd. my only guess for that is your pipping. after you shut it off the pipping starts to cool down and makes strange knocking noises.

I've noticed when washing my base 2 door that the bottom part of the quarterpanel behind the rear wheels moves quite a bit when pushed on, enough that it could make a noise, see if that's maybe your problem.

That's the only logical explanation I can think of. ( the piping rattling because of temperature change)

I've noticed the same thing in my Redline - just a few short taps every once in a while . . . I figured it was something to do with the plastic body panels & thermal expansion, it doesn't really sound like metal pinging - I do hear the ticks of the exhaust cooling when I shut the car off, but this is different. Wierd.

It's the metal part of the rear passenger seatbelt hitting against the plastic trim of the car.

I got the same thing on my SS I actually heard tice last night,right after I turned the car off, it tapped once and then when the door was opened it tapped three times. Alll sounding like it came from the rear

Yeah i was hearin that noise b 4 and it turned out that my broken sunroof switch was caught some how and kept trying to shut itself after i dislodged it from what it was stuck on the noise stoped lol it had me freaked out for about a week lol

FUEL PUMP RELAY MAYBE, I KNOW IT DOSE IT WHEN YOU SHUT OFF THE CAR IT DOSE IT AFTER ABOUT 60-90 SECONDS, SO I THINK IT'S THE FUEL PUMP RELAY, EVEN AFTER STARTING THE CAR IT JUST MIGHT BE KICKIN' IN THE RELAY, COULD HAVE SOMETHING TO DO WITH THE SECURITY SYSTEM IN OUR CARS FROM THE FACTORY, THOSE RELAY'S CAN BE LOUD.
:cssNET: :confused: :cssNET:

Yeah I get the same sound comming from the rear somewhere. I thought it was just me.
I dont think it is the exhaust. and dont think it is body panels either.


Yeah fuel pump makes good sense. thanks. :bow:

I get the same thing. When I leave to go to school in the morning and let my car sit for about a minute or 2 I hear the tapping noise. like it came from the back of the car. it happened while i was driving to so when i got home i thought stuff was rolling around in the trunk but no.... weird

FUEL PUMP RELAY MAYBE, I KNOW IT DOSE IT WHEN YOU SHUT OFF THE CAR IT DOSE IT AFTER ABOUT 60-90 SECONDS, SO I THINK IT'S THE FUEL PUMP RELAY, EVEN AFTER STARTING THE CAR IT JUST MIGHT BE KICKIN' IN THE RELAY, COULD HAVE SOMETHING TO DO WITH THE SECURITY SYSTEM IN OUR CARS FROM THE FACTORY, THOSE RELAY'S CAN BE LOUD.
:cssNET: :confused: :cssNET:


It's more like a knock not a ticking noise and it comes from the rear of the car

My 05" LS makes the same noise. I always assumed it was something to do
with the electronic fuel pump. My 96" Chev. P/U makes a simuliar noise when
it is shut off, which is coming from the elec. fuel pump.
;)

It's more like a knock not a ticking noise and it comes from the rear of the car
NOT ONCE DID I MENTION A TICKING NOISE, I JUST SAID THOSE FUEL PUMP RELAYS ARE LOUD. IT COULD BE A TICKING NOISE IF IT WERE QUIET, BUT IF IT WERE LOUD IT COULD BE A KNOCK.

I get the same thing, ushually when i have come to a stop for whatever reason.

yeah, well wrap your minds around this one.. my 2000 GP GT does it too.. i also though I was going crazy when I heard it, because I couldn't figure out where it was coming from.. it sounds like someone is in my trunk and they're taping metal with something sharp.. i actually pulled over once to check the trunk, thought maybe someone put a body in my car or something :p still don't know what it is, but I don't hear it anymore

truth is guys, when gm was building these cars they built them in a abandoned garage that had a giant fire and 1000's died, 20 years ago and there are trapped souls in your cars..
lol j/p!

It is scary though isn't it. Makes me get the chills every time it happens.

any 2.4's doing this too? i want to know what to expect

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!! :-D

Alright, this strange occurance has happened to me a total of 4 times since I bought the cobalt. The first time it happened was at a red light. *tap*tap*tap* It sounded like somebody was knocking on my window. I look back to see but nobody was there. The next time I was outside of my girlfriend's house. *tap*tap*tap*tap* I jumped around, nobody again. Etc... etc.... This sound is almost exact to somebody knocking on the body or glass of my car. Has anybody else experienced this "Ghost?"


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.

truth is guys, when gm was building these cars they built them in a abandoned garage that had a giant fire and 1000's died, 20 years ago and there are trapped souls in your cars..
lol j/p!


Well, at least they get to drive around in a nice car!!!!! :lol: 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
:cssNET:

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.... :lol: 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! :ca: :cssNET:

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

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.

:ca:

I've had the same thing in a Prelude and my girlfriend's c230 kompressor coupe... I was told by several different people that it's the abs?

The story is the plant in Lordstown Ohio which builds the Chevy Cobalt is haunted by the ghost of John Delorean. Delorean never forgave GM for sacking him from his job as General Manager of the Chevrolet division, and now haunts the facility placing squeaks, rattles, pops and other noises into the Cobalts as they roll off the end of the line.

MY Advice to to hang some garlic, fuzzy dice or other mojo from your rear view mirror, and always remember to walk BACKWARDS WITH EYES CLOSED around your car three times, chanting "Long live the DMC" before using the key or remote to unlock the doors.

Works for me!! :D
WopOnTour

Just had my first experience this a.m. Waiting at a stopsign and it was loud as hell! Knock, knock, knock! Sounded like someone was knocking hard on my window! It was from the rear somewhere. Kinda funny! Just strange. I've heard the car/abs/or whatever sometimes after its shut off, but this one was really loud. As long as its a friendly ghost! :cool:

OK I have had this happen a few times. How many of you have the recaro's? As stupid as it may sound, I swear atleast 5 times it sounded like someone was knocking on my window but behind me. I lean forward in my seat and then lean back and forward again and the sound happends again, I finally realized this is from my seat. Its only when your in certain positions and its wiered to hear your seat make that noise, but for those of you who have had this happen with your car off this may be the cause. It so sounds like a tap on glass, but it someone comes from my seat depending on how I lean back in it.

happened to me one morning, scared the shit outta me!!!

I have the base model coupe so it is no way that it could be the abs so i think it has to be the latch or something.

it should b the GAS CAP
it happens 2-3mins after the car starts... fuel pressure builds up and locks the GAS CAP

I had it happen to me in a drive thru too. Scared the crap out of me I thought someone was knocking on the passenger rear side of my Cobalt but no one was there. F R E A K Y !!!

i have had it happen to me as well, i dont like it, dont care if it is the abs. someone please post a fix as soon as you know the problem for sure

For the answer to the "noise", refer to "Knock, Knock,Knock" thread and view posts; 20, 24, 31 and 37. You are not going to fix anything.

change the stock muffler it will go away ;)

wow this is crazy ive never had it happen though

happens in my base model all the time, I've come to accept it and live with the ghost of cobalt past peacefully

all of our sport cars does this!

LOL i have the same thing, i kind of figured it was a loose antenna because it kind of sounds like my antenna is rattling, but its never loose.. good to know im not the only one who notices this :lol:

That happened to me today for the first time and i've had the car for a year now! It scared the hell out of me

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.

Humh. I noticed the other day when I start the car, I hear a "clicking" or "taping" noise from what sounds like the back of the car, maybe the trunk area. I am not sure whether it just started, or I never noticed it the last two weeks.

Anyhow, I don't think it is the exhust poping. I know what that is like when it is warm. It is more of a "ping" like throwing a coin into a coffee can. Best way I could describe my noise at startup is like something loose shaking. I guess it is almost like someone tapping on the trunk or something. I though maybe those crappy clips holding the exhuast were loose, but everything looks tied down!

So maybe it is what NJBLUESS says? I have no clue about what he is describing, other than the fact that it is related to engine mangement and emission sensors. The engine fires fine, and like no less than one second after it is running, I hear this "clicking" noise from the rear. I'll have to watch and see if it does it on an empty tank or a full one!

All these new car sounds and smells worry me too much! I need to relax more!

I've got that same damn thing! I can't figure out what it is either!

For me, it's not so much a click, but more like someone is physically knocking on the body panel and it always goes in threes. However, the fuel pump idea sounds good to me b/c it's always when I've been driving for short distances, never after I've been warmed up for a while.

well...i had this happen for the first time tonight.....when i got home i stayed outside to have a smoke and i heard the ghost knocking......it does sound like a muffler thing to me tho.....which doesnt make sense because i drove home like a grandma tonight.....shitloada cops

I actually got that noise too while i was in a drive thru I looked back and nobody was there. Then when I got to work While I was getting out I heard it again and it was my antenna. It wasnt screwed down all the way and when it was swaying the base of it was knocking against the car.

The nock, nock, nock is your gas tank checking itself for fuel pressure. Our superchargers aren't all that great when it comes to building pressure. You know how you turn your key to the 2nd aux. for a couple of seconds before starting your SS/SC? It's to build fuel pressure. The knock is just your tank checking fuel pressure. It only happens when you first start your car, just turn it off or idle for a while. Fuel pressure is key in the SS/SC. Hope that helps. It is the truth. :twothumbs

My neighbors malibu did this yesterday, scared the shit outta me. She looked at me like I did it to her car...then we both laughed and I went back to washing my car.

The nock, nock, nock is your gas tank checking itself for fuel pressure. Our superchargers aren't all that great when it comes to building pressure. You know how you turn your key to the 2nd aux. for a couple of seconds before starting your SS/SC? It's to build fuel pressure. The knock is just your tank checking fuel pressure. It only happens when you first start your car, just turn it off or idle for a while. Fuel pressure is key in the SS/SC. Hope that helps. It is the truth. :twothumbs
Please research for information you just described. NO GM vehicle tests or monitors fuel pressure within its engine managment system.It has nothing to do with the supercharger, either. I have explained this before, IT is the EVAP system testing itself!! The vent soliniod is the cause of the tap, tap, tap noise! The noise is as if someone knocked 3 times in the trunk of you car. If no one believes this, stop in my shop and I will demonstrate the noise (with a Tech 2 you can command the soliniod on and off and hear the noise inside the car)
Now, as far as you stating that your assumsion is truth, please feel free to explain. Also, I would like to add that, Engine Performance, Emissions and Elecrtonics is my specialty in my field, So, I am always looking to learn something new!

You mean it's NOT DeLorean's ghost?? Damn EONV tests!
Wop