You’ve definitely heard this noise before. It’s that quiet “ping-pang” of metal that you hear after turning off your car. The question is, what’s making that noise, and should you be worried about it?
We always like to imagine the noise is just a band of Keebler elves playing bocce ball inside our exhaust system. Unfortunately, the truth is less mystical. The “pinging” noise you hear is coming from the hot metal cooling under your car.
Here’s what happens
As you drive, the engine and all the parts around it start to heat up and expand. Once you turn the car off, those metals will cool and contract. When you have different metals cooling off at different rates, they sometimes “bump” into one another. These tiny bumps produce the “pang” or “ping” you hear coming from your turned-off car.
Think of it like partner dancing. When two people are grooving to the same tempo, their movements are synchronized and functional. But, if those two people put ear buds in, one playing Beethoven’s Ode To Joy, and the other playing Psychosocial by Slipknot, be sure to stand back because a collision is eminent.
Is that bad for the metal?
It’s not exactly ideal, but it’s nothing to worry about. The more metal heats up and cools down, the more brittle (prone to fracture) it becomes. This is a very slow process, though. When it comes to metal, your biggest enemy is rust. If you can keep the rust off your engine parts, then these “ping” and “pang’s” are as trivial as they sound.
Is your car making a weird noise when it’s turned off? If so, and you can’t identify it, someone at the Leith Volkswagen Raleigh service center can. Most noises are nothing to worry about, but don’t take the chance if you’re concerned. Nothing beats peace of mind.