Kate on Cars - December 2011

Those Winter Squeaks and Rattles, Part 1

So the weather changed and the temperature dropped, and suddenly your car is noisier than usual. Maybe you only notice the noise on rainy days or only first thing in the morning. Or maybe only over bumps. Why would this be? Is it dangerous? What does it mean? Why now? 

When your car is making an unusual noise it is trying to tell you something. Unless you work on your own car, it’s best to call a repair shop and set up an appointment for them to inspect the vehicle. It’s my goal in this column to give you some kind of basic general understanding of some sources of the common squeaks and rattles so that you are a little more comfortable with your car. When you take your car to the shop, the first procedure your repair shop will do is locate the source of the noise so they can tell you what it will take to fix it. Let’s look at some causes of cars squeaking and rattling.

What Happens to Cause Squeaking and Rattling?

Squeaking is often caused by metal-to-metal contact. The steering/suspension system on your car is composed of the metal pieces that move up, down, left and right as the car’s body moves - control arms, stabilizer bar links and tie rods to name a few. They are in some ways like your arms and legs, knees and elbows.

The metal joints are protected by a rubber- or plastic-composite bushing. If these bushings wear out (which they inevitably do), you may begin to hear a squeaking noise as the metal touches metal, like fingernails on a chalkboard - ouch! This noise is an indicator that something is wrong and the car should be inspected by a professional automotive technician. Often these types of steering/suspension noises begin and have some time before they become safety issues. Other times the failure occurs more quickly and a prompt repair is required to keep you safe and avoid further costly damages and more failed parts.

So why is it louder now that it’s winter? 

Metal and other materials are sensitive to the environment. They shrink or swell with temperature and humidity. Your car is composed of different types of metals and materials, and guess what – each has it’s own properties and expands and contracts at a different rate from the others. As clearances change, so do noises. So any time we have a climate change we have more potential for noises.

Even for skilled automotive technicians it can be tricky to locate the sources of car noises. We technicians have a few tools that we use when diagnosing noises, primarily a set of “mechanic’s stethoscopes” (similar to a doctor’s – see photo below) and a set of “chassis ears.” I’ll describe these tools in more detail in my next article.

Remember: when your car has a funny noise it is trying to tell you something. Your safety and the safety of your passengers could be compromised if your car is not functioning properly. If your car is making an unusual sound it’s best to have it inspected by a professional as soon as possible. At least then you’ll know whether or not the source of the noise is a safety issue and what the time frame is for getting it repaired.

And please remember, your automotive shop cannot correctly diagnose the sounds from your car without bringing it into a shop to have it professionally looked at. So plan on taking these extra few minutes to do this. Your safety and the safety of your family is worth this visit.