3 Engine Sounds You Should NEVER Ignore

mechanicalYou do not have to be a car expert to know that your engine is crucial and that engine repair is expensive. So, you don’t want to put off engine maintenance, especially if you are noticing a few characteristic engine sounds.

Transmission Slipping

Whether your vehicle is a standard or automatic, your transmission controls which gear your vehicle is in, and the gear your vehicle is in affects power, speed and fuel efficiency. If your transmission is slipping, your vehicle may not be responding to gear shifting normally and/or may switch gears when it’s not supposed to.

What you will hear

If your transmission is slipping, you will likely hear your engine rev—like when you are in park or neutral and hit the gas pedal—unexpectedly and/or a change of pitch in engine sounds that accompanies a gear shift when you haven’t actually changed gears.

What you may observe or feel

If your transmission is slipping, you may notice:

  • Hesitation between when you shift into drive or reverse and when your vehicle actually “catches” and starts to move
  • Difficulty accelerating
  • A clunk or thud when shifting gears

Transmission slippage can be very dangerous because it compromises the control you have over your vehicle’s movement. Your car may lurch, decelerate or stall without notice, putting you and surrounding people and property at risk. This is a drive train issue that needs to be taken care of immediately.

Engine Running without Oil

There are dozens of moving metal parts in your engine, and to move smoothly with minimal friction and heat that cause excessive wear, your engine needs lubrication. It takes a lot of miles and/or extreme conditions to run out of oil, but it happens. Your vehicle will run without oil for a short time, during which you could cause irreparable damage.

What you will hear

An engine running without oil will likely at first sound louder and rougher, which makes sense because the engine is functioning normally, you’re just hearing the metal on metal. If the hood is down, an engine without oil may sound like an automatic card shuffler, just louder. But, as the engine starts to build up more heat, you will hear more distinctive metal-on-metal sounds—tapping and grinding.

What you may observe or feel

An engine without oil may not feel any different in the driver’s seat. However, heat will build-up quickly, so you are likely to see your “Check Engine” light illuminate as engine temperatures move into the red zone.

Although not highly tested, many cars may run for about 15 minutes without oil before locking up. If you hear any sound that indicates low or no oil, turn your car off immediately. While you can add oil yourself, it may be better to have your car towed to a mechanic to check if there has been any engine damage or a leak in the system that caused you to run out of oil in the first place.

Piston Slapping

You’d be amazed (because we’re amazed) at the tight tolerances between all the moving parts in your engine. In a well-designed, -machined and -maintained engine, parts only move in the directions they are intended to go to generate power. However, over time, parts wear, especially if not properly lubricated, and that can lead to spaces and gaps between components that make for irregular engine sounds, like piston slapping.

Piston slapping occurs when the bottom part of the piston (the “skirt”) slaps against the cylinder wall.

What you may hear

Piston slapping creates a regular “clinking” sound as the engine runs.

What you may observe or feel

If your engine has a piston slap, you will likely notice no difference in the driver’s seat. However, because the slap is created by space in the cylinder that allows the piston to travel in something other than its direct up-and-down motion, the air-fuel mixture let into the cylinder is not being compressed adequately, and that will likely result in lower engine efficiency. In other words, you may see a drop in MPGs.

Unfortunately, piston slaps are not really fixable. They generally require rebuild. And while no engine rebuild comes cheap, putting it off could lead to even more expensive fixes or simply needing a new car because yours is no longer drivable.

Train Your Ear to Hear Warning Engine Sounds

A written description of an unhealthy engine sound is good, but hearing call-your-mechanic-ASAP noises is better. To get an idea of what a slipping transmission, engine without oil and piston slap sound like, visit Cling Clanger’s car noise library. There are also a number of YouTube videos that capture these engine sounds.

Still, because engine repair is so expensive, it’s always better to err on the side of caution. If you hear any engine noise out of the ordinary, bring your car to Quanz Auto Body. Our ASE-certified technicians have the trained ear to identify many engine sounds within a few seconds, and we can tell you whether or not you can wait for a scheduled maintenance appointment or need to leave your vehicle with us. We also have advanced diagnostic equipment to troubleshoot any other maintenance issues that might be contributing to engine noise. Contact us or simply visit our Westside location for maintenance service.