What's "That" Noise?
(from the BMW CCA Pinetree Chapter Newsletter)
There you are... Driving down the road when, suddenly there seems to be an unsettling noise happening! Now what to do? This kind of thing can happen at any "inopportune" time. It also seems that winter cold and it's less than perfect roads make for even greater occurrences.
The first thing to do is get a feel for safety and the severity of the noise. If this is a sudden noise and has any affect on road feel it's time to take some action. First look around and in your mirrors for others and a safe place to slow down or pull over. Glance at the dash for any indicators or warnings. Once you have identified an area to pull over, or are satisfied that you can make it to a secure and safe place and have gotten there. You should start to analyze the problem. Did the noise stop when the car stopped? If not, shut the engine off and see if that makes it stop. Now get out and walk around the car to see if anything looks or maybe even smells unusual. Also look beneath the car to see if anything is leaking, hanging down or dragging. If the sound was still happening when the engine was running, open the hood and take a peak inside for anything obvious. If any dash warnings were present use these to give direction as to where to look. For instance an "anti-lock" brake light may mean to look for something in or around the wheels. A temp gauge registering hot or "check engine" light. Would be under hood related.
If everything looks attached, nothing is dragging and the engine runs quiet. It may be ok to attempt to drive further. Start by driving around the block or along the shoulder at a slower pace. If the noise is still occurring, now try to note the area it is coming from and what factors relate to it. Is the noise caused by bumps? Does it change with speed? Does the use of the brakes affect it? Next is there any abnormal feel to the steering, braking or handling of the car? Is there a vibration associated with the noise? This will help in determining the risk in continuing to drive the car. This is also valuable information for a repair shop to use in determining possible causes. If the vehicle seems safely drivable without doing further damage, continue on but use caution and be aware of changes or worsening of the problem. If there is any question of safety or further harm to the vehicle it's best to get it towed.
There are too many possible causes of a vehicle noise to discuss here. A noise can be sudden or gradual. Generally small noises turn in to bigger ones so get these looked at promptly. Sudden noises can be from road debris or an unnoticed road imperfection doing damage. These can also result from the neglect of the smaller ones. Tires can cause a range of noises and vibrations. Make sure these are inflated correctly, show normal wear and have ample tread depth. Knocking noises that happen over bumps, usually are from suspension components. But these can also be from the loose connection of pieces suspended from the car. Noises that change with road speed can be from the brakes, wheel bearings or axles. Other speed related noise can be a "whistle" sound. This could be wind noise from loose shields or panels. Lastly would be noises that change with engine speed. These can be serious and real caution should be used in continuing to operate the car. If there is any loss of fluids, burning smells, or heavy knocking, stop and get the car towed. A qualified shop should evaluate any of these to avoid more damage. This all holds true for the other noises described as soon as possible. A noise is trying to tell you something. When having your service shop look at the problem, being able to describe what you hear and feel in a big help.
Once again with any noise if in doubt about it's potential for safety or doing damage, a little inconvenience can save plenty in repairs. Get it towed.
Voit Ritch
Autowerkes Maine Inc.