How to Understand Car Noises
If the noise will not eventually result in a deadly failure for the car, the driver will likely tend to ignore it, especially because strange noises have a tendency to come and go as they please, often missing for days before reappearing again.
Yet the fact that an unnatural noise occurred is a definite signal that something is wrong with the car and you should have it looked at. If you like, a strange noise is the way in which the car communicates a fault which is not monitored by its electronic systems.
There are countless types of noises, signaling countless more or less serious problems. We will try here to highlight the ones which occur the most, but feel free to describe your experience in the comment box below and ask for advice should your car noise not be listed here.
Largely, the unnatural noises of a car originate from three places: from under the hood, from the steering column assembly or from the front wheels assembly. These are the ones you should watch out for (or listen to, to be politically correct), as they are the most likely to be the preview of some type of serious problem.
STEERING COLUMNS ASSEMBLY NOISES
One of the most common noises made by the steering wheels is a "click". It usually gets worse over time or as speed increases and it occurs when the wheel is turned. The "click" can point to a range of possible problems, including a worn or bad CV joint, worn bearings inside the steering column or low power steering fluid level.
The steering wheels in power-steering assisted vehicles also have a tendency to screech. This is an indication that the power steering belt is slipping.
As you might figure, noises pointing to problems in the steering wheel column should not be ignored. If left untended, the problems may turn into life threatening situations.
FRONT WHEELS ASSEMBLY NOISES
You car's front end will most likely make noises other than the ones intended by the manufacturer. One of the most common ones, whether they manifest themselves as a squeal, groan or grumble, happen when you apply the brakes. Some of you must have witnessed a grinding sound coming from the front wheels when applying the brakes. The most likely cause is the worn out brake pads and you should have your car checked asap.
A load, screech noise when applying the brakes is an indication that your brake pads need to be replaced. In fact, this type of noise is factory-built, sort of speak. Modern brake pads feature on the side a piece of metal which, as the pads wear out, comes in contact with the metal of the brake disc to warn the driver to go service the brakes.
Additionally, squealing can be caused by one of the following:
- dust in the drums
- distorted brake shoes
- bent backing plate
- weak brake shoe return springs or retaining springs
- bad, hard or braking-fluid saturated linings
Unnatural sound coming from the wheels can point to all brake-related problems mentioned above, as well as to bad or loose wheel bearings (the noise can take several shapes, including rumbling, growling, chirping or cyclic noise) or a worn or bad CV joint.
Front wheel noises will also point to some not-so-common problems, like abnormal tread wear in the tire, ply separation or a bent wheel.
All types of noises coming from the tires should prompt the owner into taking the car in for an inspection. As is the case with steering failures, potentially life-threatening faults could hide beneath an otherwise minor sound.
One of the most common noises originating from an engine is the at-times unbearable screech made by the car when accelerating. The sound can have only one source and that is the slip of the auxiliary drive belt or fan belt.
A clicking or tapping noise is an indication that the engine is working on low oil pressure, excessive valve lash or with faulty or damaged components.
A rapping noise coming from under the hood points to extreme bearing wear or damage, while a knock can be caused by an inoperative EGR valve, engine overheating, carbon buildup in the combustion chambers, or low octane fuel.
Additionally, the engine can tell you, through whining or chattering that the camshaft drive belt is not properly tensioned. A wrong grade of fuel, engine overheating, incorrect ignition timing or ignition system fault can be heard as a rattle when accelerating.
Engine problems can be heard from the rear of the car as well.
Incorrect ignition timing, faulty ignition or leaking valves will be brought to your attention by a bang in the exhaust (backfire), while a blown exhaust will manifest as a roar.
Depending on the car you are driving, some of the noises mentioned above can point to a different fault. Also depending on your car, the way to fix your fault may vary from model to model. What is important to know is that most likely, not being trained, you will miss entirely what the noise means. At that point, you have two options: you either go online and google your problem, or you take the car to a mechanic. Usually, the second course of action is faster and more reliable.
comments written so far
On one model of a car -long ago- we were able to hear 7 different sounds radiating from the crankshaft, caused by different problems, such as bearing wear at different places, i.e. small end, big end or thrust bearing, ring wear or piston slap, or air noises caused by faulty crankcase ventilation (now EGR).
And every model is different.
'Doctor of Motors' is a real title that can be earned by technicians from one automotive company after an extensive test.
Medical doctors have only 2 'models' to diagnose and they can verbalize their problem.
A good auto-tech is a true professional.