For the uninformed, identifying where that squeak or thunk is coming from on your car or truck, or determining where that pungent odour is coming from, can be quite disconcerting. However, being cognizant of usual noises and smells emanating from your vehicle will help you nip potential automotive problems in the bud. Early detection of strange sounds or smells coming from your vehicle can help reduce repair costs, and if you are like me, everyone hates to pay those exorbitant fees charged by automotive repair shops these days, right?
Here are some tips to help you identify some of those early tell-tale signs, just by using your nose and ears. A very common sound is brake squeal. On domestic vehicles, brake squealers are used. These are little pieces of wire that touch the brake rotor when the brakes are applied. Those are designed to alert you, the driver, that there is very little brake pad material left, and that’s the time to replace the pads. On imported vehicles, if you experience brake squeal, it may be dust particles or sharp edges on the surface of the pads rubbing on the rotor. The only way to be sure is to remove the wheel where the offending sound is coming from. The brake pads then need to be removed and checked to see if there are dirt particles or sharp edges on the surface of the pads. Most of the time, this has been the primary cause of brake squeal on these vehicles. It can happen if the vehicle is either hot or cold. Inferior brake pad material can definitely add to the brake noise list. Another problem that can happen is experiencing grinding noises when you apply the brakes. When you get grinding noises, you have to be very careful, because that is a sure sign that the brake pads or brake shoes have worn down to bare metal. When your brakes are applied, do you have the metal of the brake pads or brake shoes contacting the brake rotors or brake drums, and that requires an immediate repair.
Other grinding noises coming from your car might be from faulty or worn wheel bearings. Wheel bearing noises are more of a roaring or groaning sound. On most cars, whether front-wheel or rear-wheel drive, that sound would come from the front of the car. To determine which wheel bearing is the culprit, drive the car at approximately 30 mph/50 kph on a quiet road, and, for example, if you round a left-hand corner, the centrifugal force results in the load being applied to the right wheel. If the grinding is exaggerated, then the wheel bearings on the right side need to be checked to see if there is movement or play in the wheel. Perhaps all that is needed is for the nut to be tightened, holding the wheel bearing assembly in place. If the bearing is worn, it will have to be replaced. Conversely, if the grinding noise occurs when the vehicle is negotiating a right-hand turn on the road, then the left side (driver’s side) wheel bearing will have to be inspected.
The most common sound is that of a blown muffler or leaking exhaust. Most people recognize that sound. But one sound that is quite difficult to diagnose, even from an automotive technician’s perspective, is when one experiences a ticking sound coming from the engine compartment. If the ticking sound is experienced on a cold morning, most likely it can be attributed to an exhaust manifold gasket leaking. This noise may be misinterpreted as valve tappet noise. The exhaust manifold gasket leaking noise is the result of the contraction of the cast iron metal of the exhaust manifold and the cast aluminum head on the engine, leaving a tiny gap at the gasket, which allows for the exhaust gases to leak through. In most cases, if the leak is detected within a year, the cure is simply to tighten the manifold bolts. If the gasket is punctured or the problem has persisted for over a year, the gasket will have to be replaced and the manifold assembly machined, due to distortion.
Rumbling sounds coming from the engine compartment may mean that the cooling fan is not balanced and is vibrating, or there may be a worn water pump. The latter would result in a grinding sound similar to wheel bearing noise. A very tight fan belt will exert a load on the water pump impeller and cause the noise to be quite loud. A fan belt adjustment may all that is required to alleviate this problem. If the water pump is leaking antifreeze, then the only alternative is to replace the unit. Fan belt squeal, experienced when the engine is revving, can be rectified by tightening the fan belt. Many more noises can be identified by the average motorist, from a faulty heater fan, power steering pump, air conditioning unit, etc. Unfortunately, these repairs are beyond the scope of the average car owner and best left to a qualified automotive technician.