Hello everyone. I went to look at a g35 today. It is completely stock being sold by an auto "dealer" who consigns cars. It was so much fun to drive but what set me off was the exhaust popping after letting off the throttle. It honestly sounded super dope, but if it's going to jeopardize my engine I can't take the risk because I need this car as a daily. The car only has 75k miles, but the interior was rough. Dashboard was completely covered in carbon fiber stickers and the sides of the seats were coated in this weird black stuff. Besides that the interior was actually nice. regardless of all of that stuff, though, I am wondering if this backfire is enough to be worried about that I shouldn't buy the car. By the way he is asking 6800. Here is a video of the backfiring. https://imgur.com/a/QSuh8R1

 

$6800 with a trashed interior is way too much even with the low mileage. Really need a much longer sound clip to really hear what you're talking about.

 

appreciate it man. That’s the only sound clip I have sorry. Here is the ad if you’d like to see it. the car does not look that nice in real life. It has some dings and scratches. https://sarasota.craigslist.org/cto/...262263305.html

 

That's called "exhaust pop" not "backfiring". Sounds like they did a muffler delete and that's why you can hear the pop, completely normal.

Yes having a longer exhaust sound video would help a ton.

That price looks fair considering the mileage.

 

what’s the difference?

 

Backfiring is an old term from the carburetor days mostly, nowadays it's only really mentioned for high performance cars running too much timing advance. It's when the intake valve isn't fully closed when the spark plug fires and the explosion blows back up the intake valve and ignites inside the intake manifold. It usually ruins the intake manifold when it happens, it's almost always due to ignition timing.

The term is also used to describe an EXTREMELY loud exhaust pop typically caused by a buildup of unburned fuel that then explodes inside the muffler of a car that isn't equipped with catalytic converters. Usually sounds like a very large firecracker exploding.

Exhaust pop is normal because when you let off the throttle the engine WAS delivering quite a bit of fuel, it quickly makes a recalibration to add less fuel but it never happens fast enough to prevent the combustion chamber from being overly rich. The unburned fuel (little bits, not a lot) then pops as it finishes it's burn in the exhaust system.

An OEM exhaust is specially engineered with mufflers/resonators so you never hear this, it still happens though.