Popping noise coming from my 2012 Tuscon, after shutting off


#1

Just recently noticed in the past 2 weeks, that after shutting off my Tuscon, about a minute or 2 later it makes a popping noise coming from the back. It almost sounds like a piece of metal when it expands. Any ideas? Thanks


#2

Have you checked your owners manual? Some newer cars do automated self checks, like on the ABS system or the gas tank evaporative emissions system, with resulting “mystery” noises.

Since your noise is a “popping” sound, it might be the evaporative emissions control system pressurizing the gas tank to check for vapor leaks.


#3

Another possibility besides the above is that the exhaust system is cooling down and the contracting metal is making a noise, like when a gravity furnace in a home turns off it makes a big popcorn-like racket. Next time it’s in the shop, ask them to assess the exhaust hanger hardware for problems, loose heatshields, etc.

One other common noise source after you turn off the engine in newer cars is hvac vent doors moving into their ignition-off position, so that’s another possibility. Most likely it is among what jesmed says above.


#4

I’m with George on this one, and whether somebody is driving a Tucson or a Tacoma, it is not unusual for exhaust systems to make some popping noises as they cool down and the metal contracts.

While evap system self-checks do make noise also, these automated self-tests tend to run an hour or more after shut-down, so because the OP states that these noises are heard only a minute or two after shut-down, I think that contraction of exhaust components is the likely cause.


#5

Even though it never did it before? I bought the car new, have had it 2 years and now the popping.


#6

“Even though it never did it before?”

Possibly. Corrosion can change how exhaust systems “stick” together. Try laying on the ground next to it to pinpoint the source.


#7

Not having done it before argues against designed checks and whatnot. It would have done those since new unless something was changed. Seems like most cars used to have exhaust systems that made more moise than now. Even if it isn’t a component of the exhaust system making the noise, it could be some other part that gets warmed by the exhaust system, then pings as it cools and changes shape. Any likely-looking heat shield under there?