Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Vroom vroom sound

Could anyone tell us what makes a car go vroom vroom? Maybe something to do with revving the engine? --but if that’s the case, how does revving the engine cause the “vroom vroom”? Or perhaps it’s due to other things entirely?

Any help greatly appreciated. Thank you!!

You’re going to have to do better at describing what is going on. “Vroom vroom” is a typical way of describing what a car sounds like when everything is good. (Was it Mazda that had the “vroom vrooom vroom” ads?)

In general an engine makes A LOT of noise. They work by explosions inside of the engine. If you’ve ever heard something like a really loud motorcycle that gives you a taste. The only reason most engines are very quiet is that they have muffler systems. Once those explosions go through the exhaust system the sound is often described as “vroom vroom.”

So that’s one thing - if your car has recently gotten louder then have someone inspect the exhaust system.

Short of that post a better description along with the basics about the car - year, make, mileage…stuff like that.

You had better appreciate that “vroom-vroom” sound while you can. It will disappear with the electric cars, just as the rumble of the Ford flathead V-8 was replaced by the anemic “vroom-vroom” of today’s cars.

Mazda had a zoom-zoom campaign.

There’s another complication as well. The reason 4-bangers sound different than V8s is combustion timing. V8 engines typically have 90 degree crankshafts, which means that a combustion explosion happens at every 90 degree turn of the crank. 4-bangers have 180 degree crankshafts, also called “flat cranks”, which means that the bang happens at every 180 degree turn of the crank. The rumble/burble sound of a V8 comes from the spacing of the explosions and of the exhaust pulses. The 4-banger has only half the explosions per time frame, so the pressure in the exhaust system “smooths out” more. A V8 can’t operate on a flat crank because there’d be two exhaust pulses both being pushed into the pipes at once, and doing two-two-two combustion pulses rather than one-one-one would be a lot rougher operation. Some race engines have used flat plane V8s and run them like two 4-bangers commected, but we’ll skip that.

I wonder if it was zoom zoom I was thinking? I don’t know for sure since I rarely watch TV and then even more rarely watch the commercials. Of course, Vroom/zoom - I don’t know, sounds the same to me.

You’re right. It does sound the same.

An engine will make that "vroom, vroom’ sound when revved because it is moving more air through it at a varied rate depending on how much air is let in by the throttle. This much movement of air and it’s variation causes noise and vibration, resulting in that familiar “vroom, vroom” sound. If you are experiencing more noise (louder “vroom, vroom” than usual), you probably need to have your exhaust system inspected. The exhaust system does a lot to keep that “vroom, vroom” noise to a minimum.

While it seems counterintuitive, engine sounds also come from the air intake. I recently made modifications to my own air intake, and the sound of the engine under heavy throttle changed. In my case I liked the change, but I’ve read of people who added CAI systems and removed them because they didn’t like the new sound. If you look under the hoods of modern cars you’ll see strangely shaped things hanging off the air intake systems. These are there to moderate the noises and make the engine quieter. They operate as baffles, allowing the pulsing air (the pulsing is a natural result of the intake valves constantly opening and closing, causing a vacuum-no vacuum-vacuum-no vacuum condition) to become a more even flow of air.

Sorry for the general nature of the question–but thanks for all the great posts! This is exactly the kind of information the person I’m doing this for wanted and we weren’t having any luck figuring it out ourselves. It’s greatly appreciated–thanks again!