On my way home from work earlier, I had my music up and in the background I was hearing this buzzing from my car. I turned it off to realize that below 3000rpms, my car sounds like a diesel truck.

When I give it any gas at all, it has a "buzzing, deep rumble" like that of a diesel truck. When I got home, I crawled under the car and the sound seems to be coming from my catalytic converter, although there doesn't appear to be any damage.

This condition has just recently started because I drove it all morning and it was fine, only on the way home did the noise present itself.

Any ideas?

 

how many miles are on the car?

any mods to the exhaust system?

cats clogged or coming apart ?

exhaust mount loose or exhaust hitting something ?

 

2008 Touring 350Z. Nismo Exhaust. Nothing hanging or hitting. 18k miles...

 

damn .. your not far off mine .. I got a 07 with almost 13K

all I got is rattles in the dash

 

well .. IF it sounds like its coming from the cats .. there might be something wrong with them even though I don't see why


does the engine bog down and sound like a diesel or does the car drive just fine and theres just a noise ?

 

Car drives normal and sounds like a diesel

 

only thing I can think of is something wrong with the exhaust or cats ..


I searched around online and only thing I can see is a crack somewhere in the exhaust system will make it sound like that

probably could take it to an exhaust shop (or cheaper - a friends shop / car lift) and look up under there while someone is running / revving the car

 

Yeah I figured as much. Just wonder why it hapenned so suddenly when I didnt hit anything and its been running fine for years. Guess I'm off Meineke tomorrow...

 

lol yea wtf is that noise???

 

.. seems like a lot of people have the dash rattle problem in two spots


(my fancy picture to explain)


I got mine right in front of the steering wheel / gauges (the big panel between gauges and windshield) .. another one is in the lower dash (in front of your knees) of the passenger side .. theres a thread around that shows how to fix that one


but the one in front of the steering wheel is just the trim panel rattling .. if I could figure out how to get it off then I could probably pack it with foam or something to put some pressure against the clips .. so as soon as I figure it out I'll post up pics and stuff

when you hear it rattle .. if I put my finger on it and push slightly it stops .. so just gotta figure out how to get that panel off

but until then its loud radio or windows down to listen to exhaust FTW

 

back from hijacking the thread .. its probably your best bet to get it up on a lift and have a look whilst its running

if you take it to a exhaust shop and they find a crack .. they can easily pop out the welder and fix it

 

Nismo exhaust? You using the Y pipe by chance? If so it possibly cracked your cats. One time my test pipes unbolted itself (underbody gremlin) and it started sounding like a diesel truck. Probably wasnt as noticable as yours but def check for cracks around the y pipe and cats.

 

08? 18,000 miles? Should still be under warranty unless you put Mods?

 

pretty sure it's an exhaust leak.. I've had a few before in various cars and sometimes depending on the severity of the leak it'll sound almost like noting is wrong at higher rpms