knocking after i shut my car off

[Diana]

hey everyone...i have an 09 altima and after i shut it off it makes a knocking sound and sometimes if im in a drive threw or just parked and the car is on it will still do that!!!!!! i took it to nissan and they said that it happens way to quick so they dont know what it is...so they want me to let it get worse then bring it back...grrrrrr...anyone have any ideas???

[realmac]

I'm going to guess one of the heat shields. There is a lower front one on the catalytic converter some users have reported has become loose and makes a quite a racket.

[telcoman]

hey everyone...i have an 09 altima and after i shut it off it makes a knocking sound and sometimes if im in a drive threw or just parked and the car is on it will still do that!!!!!! i took it to nissan and they said that it happens way to quick so they dont know what it is...so they want me to let it get worse then bring it back...grrrrrr...anyone have any ideas???

Diana

Welcome to NICO

i took it to nissan and they said that it happens way to quick so they dont know what it is...so they want me to let it get worse then bring it back...grrrrrr...anyone have any ideas???

THAT IS AN OUTRAGOUS RESPONSE

Call back and ask to speak to the service manager.

Explain the problem and let him know that just because you are a female you did not appreciate their previous condesending response to the knocking in a brand new vehicle. (How many miles are on it?)

Make an appointment to bring it in, ask for a loaner, and tell them to keep it until they find and fix the problem. They can then call you to return the loaner. Just reading your post pissed me off.

You can always call Nissan customer service if the above fails to your complete satisfaction.

... so they dont know what it is...so they want me to let it get worse then bring it back...grrrrrr...anyone have any ideas???

If they are unable to figure it out tell em you just want a new freeking car

Good luck and let us know

Telcoman

[Diana]

funny thing is IT WAS THE SERVICE MANAGER!!!!!!!!!!!!!!! i have like 8000 miles on it i bought it in november of 08....there isnt a ton of miles on it and i did have a loaner car they only kept my car for 1 day....and the manager heard the knocking 3 times while i was there! grrrr it makes me so angry how do i call nissan customer service??? all the idiot said was to please work with him....i had to wait 4 days to even get it in for them to look at because they didnt have a loaner available....

[marlin29311]

Can you be more specific about a knocking noise? Where does it come from...anything more specific on the sound?

Your engine can't knock when it's turned off...that's why I'm confused.

[Diana]

it does it when its on to....its just like if you knocked once on the car....but its coming from under the hood...it does it once every few min. i realized yesterday when i drive it does too!!!!

[boystar22]

Mine does this too, I haven't been able to figure out what causes it either. I've been lazy and haven't taken it in. Mine sounds like its either from under the hood or the floorpan. It's basically a 'thunk' sound, very similar to the sound the cat/exhaust makes when its cooling off, but much more harsh. It's obviously not supposed to be popping thunking or knocking whatever 'it' is hitting. Mine does it when the engine has been shut off recently, as well as when it's sitting running (like in a drive-thru). It may do it while moving too, but I haven't noticed. Not that any of this helps your cause, but I can sympathize with you.

[jemcleod]

I have the same deal on my 2.5s, but the knocking comes from under the car, near the transmission it sounds like but could be further back.

[fskatinfrnow]

Yeah i have noticed a kknocking sound as well, but it might be something a little bit different. I have a 2007 2.5s and i notice it usually when taking off from a stop and somewhere around 2000-3000 rpm it makes the sound until i get up to 40ish mph. I have yet to find out what it is though.

[SweetRu]

Nissan service told me the noise was the metal contracting after being heated up in the exhaust system and cooling down. I was told it would not cause any issues in the future, but if I really wanted it to stop, they would have to replace the entire exhaust system.

I'm still under warranty, but I feel any repairs may lead to other serious issues in the future. I just hope the "knock" doesn't lead to any wearing in the exhaust.

[Coupeguy23]

hey everyone...i have an 09 altima and after i shut it off it makes a knocking sound and sometimes if im in a drive threw or just parked and the car is on it will still do that!!!!!! i took it to nissan and they said that it happens way to quick so they dont know what it is...so they want me to let it get worse then bring it back...grrrrrr...anyone have any ideas???

samething is happening to my car

[Diana]

NISSAN FIXED MY KNOCKING....FINALLY AND GAVE ME TWO FREE OIL CHANGES SINCE THEY COULDNT FIGURE IT OUT!!!!!!!!!!!!!! THE HEAT SHEILD WAS NOT MOUNTED CORRECTLY IT TOOK THEM 5 MIN TO FIX AND IM SOOOOOOOO HAPPY IT REALLY DOESNT KNOCK ANYMORE!!!!!!!!!!!!!!!!

[Diana]

HEY YOU WERE SOOOO RIGHT!!!!!!!!! I SHOULD HAVE JUST TOLD THEM WHERE TO LOOK LOL

[mairella]

Sweet! My 09 has the same sound and I took my car in a few times and they "couldn't figure it out" either or it "didn't happen". Which I KNOW it occurs all the time.

I will take my car up and have them fix mine as well!!

[ScorpioChris]

OMG SO HAPPY ABOUT THIS THREAD!

I have an 09 altima coupe 2.5s and have had the SAME friggin thunking noise shortly after the car is turned off and sometimes in idle.... and now with winter the noise has disappeared so im thinking it might be that heater shield thing.... next time i bring it in im getting them to check it out right away!!

thank you thank you thank you

[CoupeVQ35CVT]

Heat shield, not heater shield It's basically thin metal "plates" that cover the exhaust piping as it exits the engine and goes down below the car. That stuff expands and contracts, and if it's not mounted properly I am guessing it really causes some unusual noises, other than what they normally do.

[BR150]

NISSAN FIXED MY KNOCKING....FINALLY AND GAVE ME TWO FREE OIL CHANGES SINCE THEY COULDNT FIGURE IT OUT!!!!!!!!!!!!!! THE HEAT SHEILD WAS NOT MOUNTED CORRECTLY IT TOOK THEM 5 MIN TO FIX AND IM SOOOOOOOO HAPPY IT REALLY DOESNT KNOCK ANYMORE!!!!!!!!!!!!!!!!

Please help! Visited to 2 dealerships.. 3 tomorrow and no one believes me its the heatshield. All the techs call it from the exhaust system as 'normal'. What exactly did the dealership do to fix yours?

[fairlady2008]

i have an o8 altima and when i take off it makes this crackling or crinkling sound like crumbling metal and its only on take off or slow driving