A cyclic chirping or squealing noise coming from the vicinity of a wheel often indicates a wheel bearing or axle bearing that is failing. Usually the noise
will change with the speed of the vehicle, and it may come and go at various speeds. This noise should not be ignored because if the bearing fails, it may
cause the wheel to lockup or come loose from your car!
Don't confuse wheel bearing noise with scraping, groaning or creaking noises that may be coming from the brakes. During damp weather, moisture causes the brake
pads to swell slightly. This may cause the pads to drag slightly, creating annoying groaning or creaking noises until the pads heat up and dry out.
A clicking noise from a front wheel that is only heard while turning usually indicates a bad outer constant velocity joint that is failing.
Metallic Scraping or Grinding Noise When Braking
Brakes sometimes make groaning or creaking noises when the pads are damp, and some types of brake pads (particularly semi-metallic pads) may squeal or squeak
when they are cold. But as a rule, the brakes should be relatively quiet when they are applied. If you hear metallic scraping or grinding noises when braking,
it probably means your brake pads are worn out and your vehicle needs a brake job now. Don't delay because worn brakes may not be able to stop you vehicle in a
safe distance. In fact, if the brakes are that badly worn, there is a risk the friction material that's left on the pads may separate from the backing plate,
possibly causing the brakes to fail. Metal-to-metal contact is also very damaging to the rotors.
Hissing Sound from Engine Compartment While Driving or After Driving
If you hear a hissing sound from the engine compartment while driving or after turning the engine off, it may mean your engine is overheating and/or leaking
coolant from the cooling system. Check the temperature gauge or temperature warning light to see if it indicates a overheating condition. Do not continue
driving (especially if you see steam) as severe overheating can damage your engine.
Stop your vehicle and carefully open the hood. Look for any evidence of coolant leaking from the engine, radiator, radiator or heater hoses. If you see steam
or smell a sweet odor, it is anti-freeze leaking from the cooling system. Do NOT open the radiator or coolant reservoir cap until the engine has cooled
down, and do not add coolant until the engine has cooled.
Note: Adding coolant to a leaking cooling system won't accomplish much because the coolant will leak back out. Adding a can of cooling system sealer such as
Bars Leak or a similar product may slow or stop a small leak, but a large leak, leaking water pump or hose will continue to leak even with sealer in the
system.
Clicking or Tapping Noise from Engine
Engines can produce a lot of noises, but a metallic tapping or clicking sound means your engine may be low on oil, or is not developing normal oil pressure.
The clicking noise is coming from the valve train. If oil pressure is low because of a low oil level in the crankcase or a problem with the oil pump, the
hydraulic lifters that open and close the valves may collapse creating an increase in valve lash. This is the noise you hear, and it will be coming from the
vicinity of the valve covers on top of the engine.
Stop the engine, let it sit a few minutes (so the oil can run back down into the crankcase), then check the oil level on the dipstick. If low, add oil as
needed to bring the level back up to the full mark. Do not overfill the crankcase with oil. Also, check the engine for oil leaks. Old valve cover and pan
gaskets, or leaky crankshaft end seals can allow oil to leak out of the engine.
If the noise does not go away, and/or the oil pressure gauge or warning light indicates low oil pressure, it's not a good idea to keep driving your vehicle.
Loss of oil pressure can cause extensive and expensive engine damage.
Other engine sounds can also mean bad news. A deep metallic rapping noise can be caused by worn connecting rod bearings, and may indicate your engine has
reached the end of the road (or will soon!).
If you hear a metallic knocking or clattering noise that only occurs while accelerating or when driving up a steep hill or pulling a load, your engine is
likely experiencing detonation, a potentially damaging form of erratic combustion. Detonation can be caused by a buildup of carbon in the combustion chambers,
low octane fuel, engine overheating, an EGR system that is not working, over-advanced ignition timing, or a defective knock sensor.
Exhaust Roar While Driving
If your exhaust system has a leak, you will hear exhaust noise coming from under your vehicle that is loudest when accelerating. The noise by itself won't hurt
anything, but it does mean your exhaust system needs repairs (probably a new muffler or pipes). The dangerous part is if the leaking exhaust gases, which
contain carbon monoxide, get inside the passenger compartment. Carbon monoxide (CO) is a silent killer. It takes only a small amount of carbon monoxide inside
the passenger compartment to affect your alertness ability to concentrate and react to changing driving conditions. As little as 0.08 percent carbon monoxide
(that's only 800 parts per million) can cause dizziness, headaches, nausea, and bring on stupor in two hours. A one percent concentration of carbon monoxide
can kill a person in less than three minutes!
You should have your exhaust system inspected and repaired as soon as possible, especially during cold weather when the windows are rolled up and the heater
may be recirculating the air inside the passenger compartment. Exhaust components that typically leak include the exhaust manifold gaskets, cracks in the
exhaust manifold, exhaust pipe connections, pipes that rust through, and mufflers that rust out.
5 Warning Lights You Should Never Ignore!
OIL PRESSURE WARNING LIGHT
The oil pressure warning light comes on if your engine has lost oil pressure or oil pressure is too low for safe engine operation. You
should pull over to the side of the road, shut the engine off and check the oil level on the engine dipstick.
Possible Causes: Low oil level (due to oil consumption or leaks), oil viscosity too thin, worn oil pump, excessive engine bearing clearances
or defective oil pressure sending unit.
If you engine is also making ticking, clattering or rapping noises, it is not getting sufficient oil. If you attempt to drive the engine in this condition, you
will probably damage it - if it hasn't already suffered major internal damage.
TEMPERATURE WARNING LIGHT
The temperature warning light will come on if your engine is overheating. Do NOT continue driving if your engine is overheating as this
can cause expensive engine damage (piston scuffing, valve stem galling, failed head gasket, cracks or distortion in cylinder head). Stop driving, pull over and
shut your engine off. Open the hood and check the radiator and heater hoses, radiator and engine for coolant leaks.
CAUTION: DO NOT open the coolant reservoir or radiator cap until the engine has cooled off for at least 30 minutes. Steam pressure inside the cooling
system can blow out and burn you!
If the coolant level is low, add coolant (a 50/50 mixture of antifreeze and clean distilled water) after the engine has cooled down.
Possible Causes: Low coolant level (due to coolant leak or bad head gasket), stuck thermostat, bad water pump, broken serpentine belt, defective
radiator cooling fan, clogged or dirty radiator, exhaust restriction (plugged catalytic converter).
HINT: Turning the A/C OFF and turning the heater on HIGH may help cool down an engine that is temporarily overheating due to unusually hot weather or from
towing a trailer. But if the engine is running hot because it is low on coolant, this trick probably won't help much
CHARGING SYSTEM WARNING LIGHT
The "GEN" or "ALT" warning light, or an icon of a battery will illuminate if the charging voltage in your vehicle is low. You do not have
to stop immediately, but you may only have 20 to 30 minutes of driving time before your battery goes dead and your engine stops running (or even less time if
you are driving at night with your headlights on).
Possible Causes: Broken or slipping serpentine belt or V-belt, bad alternator, charging control fault, or loose or corroded battery cables.
Open the hood to see if the drive belt that turns the alternator is intact and is turning the alternator while the engine is idling. If the belt is not the
problem, chances are the charging system has a problem that will have to be diagnosed and repaired. Better find a repair shop soon!
BRAKE WARNING LIGHT
The Brake Warning light will come on if the parking brake has not been fully released, but it may also come on if the brake fluid level
is low or there has been a loss of hydraulic pressure in one of your car's brake circuits. Loss of fluid or brake pressure means the brakes may not be able to
stop your car when you step on the pedal.
Carefully apply the brakes to see if they are working. If they are, pull over to the side of the road, open the hood and check the fluid level in the brake
master cylinder. If the fluid level is low, the brake system should be inspected for leaks. If there are leaks, your brake system is unsafe to drive.
If the brake pedal is low or goes to the floor, pumping the pedal may apply enough pressure to stop your car. If that fails, apply your parking brake to slow
your vehicle. Also, take your foot off the gas and shift to neutral, or downshift and use engine braking to slow your vehicle if you have a manual
transmission. If all that fails, aim for something soft like a bush or open field.
Possible Causes: Loss of brake fluid due to leaks (master cylinder, calipers, wheel cylinders, brake lines or hoses), failure of the pressure
differential switch that activates the brake light, parking brake pedal or handle not fully releasing, defective parking brake switch.
WARNING: If the brake pedal feels soft, is low, goes to the floor, or you have to pump the pedal to get your vehicle to stop, your vehicle is
unsafe to drive. You should have it towed to a repair facility for repairs.
LOW TIRE WARNING LIGHT
The Low Tire Pressure Warning Light will come on if any tire on your vehicle is 25 percent or
more under-inflated. Driving on a low tire can be dangerous because it increases the risk of a tire blowout. A low tire can also cause uneven braking, uneven
traction, uneven and rapid tire wear, increased rolling resistance and fuel consumption.
Find a gas station with an air pump, and check the inflation pressure in each tire with an accurate gauge (not the gauge on the pump, which is often very
inaccurate!). Add air as needed to inflate your tires to the recommended pressure (see your owners manual or the tire inflation decal in the door jam or
glove box). For most passenger cars, the recommended pressure is typically 32 to 34 PSI.
Possible Causes: Loss of air pressure due to a leak (such as a nail or small puncture in a tire, or a bad valve stem), loss of air
pressure due to seepage (1 to 2 PSI per month loss is normal for many tires), or inaccurate or failing TPMS sensor in tire.
Checking your tires regularly (at least once a month or before any long road trip) is recommended. Check the tires when they are COLD and BEFORE you drive your
vehicle as driving creates friction and heats up the tires (causing an increase in air pressure).
Most Often Replaced Auto Parts
The following list of auto parts that are often replaced is based on frequency (most often to least often), and are based on the average wear a
typical vehicle owner should experience under normal driving conditions. It doesn't mean the parts on your car will necessarily have to be replaced at the
following time or mileage intervals, but it can give you an idea of what to expect down the road as your vehicle accumulates mileage and wear
Most Often Replaced Auto Parts:
Oil and Oil Filter- Every three to six months, or every 3,000 to 5,000 miles
Windshield Wiper Blades - Every year or two (less in hot climates if a vehicle sits outside and is exposed to sunlight and high ambient
temperatures).
Air filter - Every three or four years, or 30,000 to 50,000 miles. Filter life can be much less if a vehicle is driven on dusty
gravel roads.
Brake Pads - Every three to five years, or 30,000 to 70,000 miles. Replacement frequency can vary greatly depending on the type of vehicle
(larger, heavier vehicles wear out their brake pads more quickly than smaller vehicles), the type of original equipment brake linings (semi-metallic and
ceramic linings usually last much longer than non-asbestos organic linings), the type of driving you do (stop-and-go city driving increases pad wear
dramatically), and your driving style.
Battery - Every four to five years (mileage doesn't matter). Less in really hot climates (maybe only three years).
Headlights and/or taillight bulbs - Five to seven years, depends on how much nighttime driving you do. Driving on rough, bumpy roads can
also shorten the life of conventional bulbs with filaments (no effect on Xenon bulbs which do not have a filament inside, or LED taillights).
Tires - Every five to seven years, depending on number of miles driven annually, the type of driving you do, and the wear rating on the
tires (a higher wear rating number means the tire should last longer). Hard cornering and aggressive driving can increase tire wear dramatically. So can wheel
misalignment.
Spark Plugs - Platinum and iridium plugs should normally last 100,000 miles, or about 8 years if you drive 12,000 miles/year. Spark plugs
may have to be replaced sooner if short trip driving causes them to foul, or your engine is burning oil due to worn rings or valve guide seals.
Belts - The serpentine belt should last 75,000 miles or about six years, and the timing belt (if your engine has one) should last 100,000
miles or about 8 years.
Brake Calipers, Wheel Cylinders and Master Cylinder - Typically last 100,000 miles or more, but eventually succumb to internal corrosion
and deterioration of the rubber seals. Need to be replaced is leaking or sticking. Often replaced at second brake job (seldom necessary at first brake job).
Alternator - May last the life of your vehicle, or it may fail after 5 or 6 years of driving. The alternator keeps the battery charged,
and supplies voltage for your vehicle's electrical system. High demand applications typically shorten alternator life. Alternators are a frequently replaced
item, and also a frequently misdiagnosed car part. Charging problems can often result from poor electrical connections (battery cables or alternator wiring
harness). An alternator should always be tested BEFORE it is replaced to determine if it is good or bad.
Fuel Pump - May last the life of your vehicle, or it may fail after 5 or 6 years of driving. The fuel pump runs constantly, and can be
damage by rust or dirt inside the fuel tank. Running the fuel tank dry or driving with a very low fuel level inside the tank may starve the pump for
lubrication, causing it to fail. Fuel pumps are also a frequently replaced item, and also a frequently misdiagnosed car part. Fuel delivery problems are often
caused by plugged fuel filters, bad fuel pressure regulators, or wiring or electrical problems.
Water pump - May last the life of your vehicle, or it may fail after 6 to 8 years of driving. The shaft seal inside the water pump wears,
and eventually starts to leak. The loss of coolant will cause your engine to overheat.
Fuses - You may never have to replace a fuse on your vehicle, but fuses are a frequently replaced item because of electrical problems.
Fuses protect against current overloads, so if a fuse has failed the circuit or component that the fuse protects may have a short or overload. Replacement
fuses MUST be the SAME AMP RATING as the original fuse. Never substitute a fuse with a higher amp rating as this may increase the risk of a car fire!
Engine Sensors - Most sensors should last upwards of 150,000 miles, but accumulated time and mileage can cause some sensors to fail much
sooner. A bad sensor will usually turn on the Check Engine Light and set a fault code. Oxygen sensors on late model cars should usually last upwards of 100,000
miles, but may be fouled at any mileage by coolant leaks or an engine that is burning oil. Throttle position sensors can develop worn spots causing erratic
readings. Crankshaft Position Sensors can develop internal cracks or shorts from exposure to engine heat that affect their output. Same for coolant sensors.
Mass airflow sensors may become contaminated with dirt or fuel varnish.
Muffler - Most late model original equipment mufflers are stainless steel, and will typically last 10 years or 100,000 miles (or more)
depending on environmental exposure to road salt and moisture.
Shocks & Struts - The shocks and struts on many vehicles are NEVER replaced during the life of the vehicle. But after 50,000 to 75,000
miles of driving, many shocks and struts are getting noticeably soft. Replacing these parts is often recommended to restore like-new ride and handling. Shocks
and struts may also be replaced at any time to upgrade performance handling.
Clutch - Varies greatly with how the vehicle is driven, but normally should last up to 100,000 miles with normal driving. Towing,
aggressive driving and poor driving habits (such as "riding the clutch") can drastically shorten the life of this component.
Automatic Transmission - Should last the life of your vehicle, but may fail at any point from 70,000 miles on. Towing, aggressive driving
or anything that causes the transmission to run hotter than normal can shorten its life and lead to failure.