What is That Noise? Automotive Sounds and How to Locate Them
Picture yourself riding through the desert and suddenly you hear a noise emanating from your car you never heard before. “What the heck is that noise?” you ask yourself over and over, or “Am I hearing it or imagining it?” Then you grapple with whether or not you should continue on to the nearest service station or stop the car to prevent any further damage. Without the proper knowledge to make this important decision, drivers may find themselves taking on a lot of stress at a very inconvenient time.
One of the things most car owners don’t realize is that cars, like people, can have many types of issues with them. As well, they make many different types of sounds, running well or not so well! The informed car owner can make a better decision on whether to seek the help of an automotive expert with simple diagnostic tests, using simple tools (or even no tools) and a bit of knowledge to assist them with this decision, lending them peace of mind along the way. In this article, I hope to offer you insight to some of this knowledge. After reading, you may find yourself thinking on a more simple level when dealing with your car’s issues.
Cars have the potential to make a wide range of sounds: clicks, ticks, pings, bangs and pops. Some are more serious than others. If that noise is driving you batty and you aren’t near a mechanic, pull the car safely to the side, taking all safety precautions into account. While still in the car and the car running, listen to see if your car is still making the noise. If it is, the sound is most likely related to the engine in some way. If not, then it is more likely the rest of the car. Either way, we have isolated the noise into two areas of importance, moving or not moving.
Let’s assume we can still hear the noise with the car running but motionless. We can further isolate the noise by simply walking around the vehicle once or twice listening for the sound and where you can hear it the loudest or most frequently.
Even though, in most cars, the engine is located in the front of the car, the engine’s exhaust travels the length of the vehicle so anywhere along that system, noises can be created through defect or vibration. The further to the rear you find the noise, the less serious the problem. A general rule of thumb for today’s front-wheel drive vehicles is any noise from the driver’s door to the back of the car (while the car is motionless) would not hinder you from driving to a service station, or home.
The noises you could expect to hear coming from an exhaust that has a hole or crack leaking exhaust somewhere throughout the system would sound both low-pitched and high pitched simultaneously, sounding similar to a snare-drum with a bit of a thump at the same time in a repetitive pulse (due to the opening and closing of the exhaust valves in the engine). If you looked under the car where the leak was emanating from it would be more pronounced. You can drive home, but get it fixed. Leaky exhausts only get worse and can diminish your vehicle’s fuel efficiency and performance, depending on the location of the leak.
If the noise is still in this area but is more of an occasional noise with a pinging, clang, or pop, then it might not be a leak. Clangs and pings are often related to cool or cooling tins that run along the exhaust system and between it and the floor of the car to keep those areas of the car from getting hot. They can ping just from the increase/decrease in temperature but a loose tin will also ping and/or bang. Again, this is not an emergency but not something that should not be left to further deterioration if you can help it. A popping sound coming from your car’s tailpipe is a signal that something isn’t exactly right with the engine. It could mean the car needs a tune-up; a sensor might not be working properly, and so on. Most of this is negligible and you can survive the drive to a service station but again, nothing to ignore. Allowing your engine to burn fuel improperly over a long period can cause damage to your engine’s components which can lead to significant repair expenditures.
So, let’s say that behind the front doors the sound diminishes and it seems most apparent toward the front. You’d move around and try to determine what side of the car as well as whether the noise came from the very front of the car or more toward the windshield. Most front-wheel drive cars have the engine belts and pulleys on the passenger side of the car with the transmission/transaxle on the driver’s side. Knowing this, you should hear more noise on the passenger side even in a new car, but it is a peculiar sound that you seek.
With all that noise coming from such a crowded area, what can you do to pin it down? First, be safe and absolutely certain you don’t have hair, jewelry, or clothing dangling into the engine compartment while it is running, the dangers are real when dealing with the belts and pulleys which usually are not covered very well! Once you have made sure you are clear to peer in, do so listening closely as you move along the engine compartment.
Still having trouble pinning it down? Do you have a newspaper handy, a folder; maybe you have a funnel in your trunk? Maybe you are getting the idea…something you can roll up to make a cone or megaphone shape. This will make a great listening device in a pinch. By pointing the wide opening toward the area of the sound and listening at the small end your ear will lead you into a rough area of the sound. Once you have found it you can flip the megaphone around and trace the entirety of the roughly defined area, with the small opening, to pin-point the offending component or location. This will give you great satisfaction, if nothing else that you have a rough idea what is going on with your car. This would also greatly aid a mechanic in confirming the problem, so you could save yourself a big repair bill and, give you peace of mind.
A variety of sounds can come from under the hood, some of which are listed below. Keep a list with you in your glove box so you can reference them:
-Ticking – Typically, low oil can result in a constant tick, tick, tick in rapid succession – Location: This noise is normally on the top of the engine unless your engine is a V-6 or V8 in which case, on front-wheel drive vehicles, it would be front or back of the engine. Trucks and rear-drive cars with V-type engines would have the noise on the left and right sides. Diagnosis & Prognosis: Check oil level and replace what is lost, if it is low. If it persists, consult your service professional. The actual ticking sound is from a lack of lubricant at the lifter/valve stem, rocker arm, push-rods (if equipped) and camshaft causing a slight delay in the spring return or the actual pushing movement resulting in a slight gap in the contact of a few of these components causing them to tap (or tick) against each other. Other sources of “tick”: Normal operation of A/C compressor (occasional tick or clack); Debris in electric fan, clear debris with engine and fan off (allow to cool prior to cleaning); Exhaust leak at engine, seek professional help but you are OK to drive.
-Squealing – Engine belts are considered a wear item. This is because they are attached to moving components (pulleys) and suffer a fair amount of friction over time. They also dry out and crack under heavy use or being left to the elements, particularly in dry states like Arizona. Location: Passenger side of engine compartment on FWD cars and Front of engine compartment on RWD cars and trucks. Diagnosis & Prognosis: Harder to pin-point to a small point with a makeshift megaphone. Shut off car and look to see if there are indeed cracks on the belt(s)…you can check by depressing the belt and looking for cracks as it flexes. If you can see cracks with or without this action then you should plan for a replacement immediately. Once confirmed, make an appointment with your service professional. An unusually dry belt can squeal for no other reason, for this you can buy a spray can of Belt Dressing to mitigate the noise. It helps to condition the belt for better grip. Other sources of a squeal: Or squelching would be low power steering pump fluid level, check and fill as needed, PS pumps can fail and cause a great deal of squelching. Seek a professional if you believe this is the cause; Water pumps have a bearing that can get worn and squeal, seek a professional; Idler pulley or wheel bearing, seek professional.
-Pinging and knocking – This can have a few sources but usually have to do with your ignition and fuel system. It could be as simple as the quality of fuel you pumped in the tank or an engine in need of a tune-up which is sometimes referred to as pre-ignition. This can happen from poor maintenance schedules or filling up at the wrong fuel station. Diagnosis & Prognosis: Start by fueling at another location. If the problem persists make an appointment for a tune-up (new spark plugs, air filters, etc.) and run a fuel injection cleaner fuel additive through your engine. In most cases, this will clear it up. Other sources of pinging and/or knocking: Poorly functioning EGR or computer sensors, seek a professional. Sometimes a clanging sound in the engine cannot be pin-pointed and this could be connecting rod bearings. This is significant and should be seen by a professional before serious damage to your engine occurs.
-Gurgling – 99 times out of 100 this is due to the cooling system not doing its job. Boiling coolant could be heard from the coolant reservoir and even through the hoses. Diagnosis & Prognosis: Be safe; NEVER remove the radiator cap or reservoir cap when the engine is hot. Allow engine to cool and check the reservoir’s level indicator to give you an idea if you need coolant. Add as needed. If there appears to be plenty, then there is a high likelihood that your thermostat is not operating as it should. One obvious indication of this is that your heater may not heat like it used to or maybe not at all. An inoperable electric fan while in heavy traffic can also cause the temperature to soar. Seek a professional for any of these repairs as needed.
Are there other areas of odd noises? Absolutely, maybe you hear noises when you turn on your heater fan. A mouse could have stashed some debris in your auto’s vent ducts. You may hear a squelch which may be the blower belt slipping due possibly to a bad bearing attached to the blower/electric motor. And while we are in the car, maybe you hear a noise as you drive, it could be something as simple as a door slightly ajar or a window open just a touch.
If the noises are heard only while the car or truck is in motion then you could be dealing with suspension or steering abnormalities (clunks, banks and pops) or possibly drive train issues such as bearings (grinding and vibration). Brakes will also make plenty of noise when they are going bad (screeching = built-in pad wear indicator), already bad (grinding when brakes applied = pad level significant with metal to metal contact) but also if brand new (slight squeak or squeal when vehicle is in motion = metallic/semi-metallic brake pads are guilty of this and is a result of a small burr or fragment hanging away from pads rubbing on the brake rotor. This is a defect of the design, not of the pads and is normal and not considered alarming. However, as with any noise you have any doubt about, check with a professional for advice, especially when it comes to brakes, steering and suspension.
Although there are many noises a car can make over its lifetime, hopefully this will give you an idea of some of them, and help you decide whether you should continue your journey of a trip to the store or a day away business commute.
Source by Barry Morris