Last week I covered a few of the noises your car can make, mostly very basic sounds for very basic problems. This week I’ll go into some sounds and car detail problems that you may not be familiar with, or you may not have paid any attention to.
Let’s start with power steering. Most of the time you never get any real noise out of this system, but when ever the power steering is drained, for what ever reason, and then refilled, air can become trapped in the system. This sound will be a “buzzing” and, depending on the system, can have a high pitch or a low pitch. Normally after a few moments of system operation the system will expel the air and things will quiet down. Another system that can create a lot of noises are the brakes.
If you hear a very faint high pitch squeak that disappears when the brake is applied, this is the brake pad wear indicator rubbing the rotor. It’s time to have the brakes checked and probably replaced. When the new brake pads are installed, the mechanic will use a backing on the pads to eliminate any vibration when the brakes are applied. If this backing is left off, you will normally get a loud squeal when stopping. Now, if you get a grinding sound from the brakes, then you missed the faint squeak of the warning clip, and the brake pads are down to the metal. In this case you will probably need to replace the brake rotor as well as the pads, causing you to make a very loud noise!
After starting your car, if you have a knocking sound that appears to be coming from the bottom but goes away when you put the transmission in reverse or drive, the most likely cause of this is the torque convertor bolts are loose. Of course, this is if you have an automatic transmission. If you have a manual transmission, you may experience a high pitch squeal that disappears when you apply the clutch. This is normally caused by a bad throw-out bearing. Another sound that’s related to your transmission is the chirping sound along with a jumpy speedometer. This is normally because the speedometer cable is dry and needs to be lubricated. Now, let’s look at the sounds your motor can make.
We all know the sound your engine makes when it’s running it’s best. “It purrs like a kitten.” But when it’s not running well, it can make some very strange and unwanted noises. Engine ping, or detonation, is the most common of these noises. Pinging can be caused by a number of things: timing, EGR valve, knock sensor and even just bad gas. Whatever the reason, this should be corrected as soon as possible as major engine damage can result! If your engine makes a low knocking sound that appears to be coming from under the valve cover, this is normally a lifter problem. Either a bad lifter or a lack of oil to the lifter.
Another knocking noise your engine can make is caused by carbon inside a cylinder. This can be very hard to diagnosis if you haven’t heard it before. This will normally disappear after the motor has been running a little while. Another sound that your motor can make is a very sharp snapping that relates to engine speed. Although very easy to hear, it can be difficult to track down. This sound is normally caused by spark jumping to ground. You may have a bad distributor cap, plug wire or even a bad or broken spark plug.
The last sound I’d like to cover is the cooling system. Normally the cooling system doesn’t make a sound at all. But, when the thermostat sticks in the closed position and the engine overheats, it can sound like a mule is inside the radiator trying to kick it’s way out. If your motor overheats and you hear this, get away from the car until the motor cools down and the noise stops! Did I forget something? Have a noise you need help with? Send me an email!