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Using your senses to diagnose car trouble

Save money! diagnose your car and schedule a Car Service

To avoid breakdowns and save money on car repairs in the long run, we advise motorists to keep an eye out for any abnormal smells, noises and other tell-tale signs that something may be wrong with their vehicle. The ability to diagnose these warning signs will help motorists keep on top of any required car maintenance and potentially mitigate future breakdowns or costly car repairs.

AA Patrol of the year, Paddy Finn has the following pointers for motorists:

Pay attention to what you see

One of the easiest ways for a driver to identify a car problem is if they see it for themselves. A puddle beneath the car or smoke rising from the bonnet are classic signs that vehicle maintenance is required.

  • White smoke from the car’s exhaust can indicate water or antifreeze has leaked into the vehicle’s engine cylinder resulting in a failed head gasket.
  • If black smoke is coming out of the vehicle’s exhaust, there may be problem with the fuel injection system, the fuel pump, the engine computer, or the carburetor.
  • Blue smoke coming out the vehicle’s exhaust may mean a failing gasket, O-ring, or seal.
  • White smoke from under the car's bonnet may mean the vehicle has a leaky water pump or radiator.
  • Black smoke from under the car's bonnet can indicate burning oil, which may mean the vehicle has a leaking gasket.
  • A puddle of bright green, slippery fluid under the car may mean the vehicle’s radiator is leaking.
  • A brown oily puddle under the car may indicate the vehicle has an engine oil leak or a lubrication leak.
  • A pool of red fluid under your car can mean the vehicle has a transmission or steering fluid leak.
  • A clear puddle may be water from the car’s air conditioner or a power steering fluid leak.
  • Blue fluid beneath the car usually means a leak in the vehicle’s windshield washer system.

Follow your nose

  • A hot oil smell while driving may mean that the car’s engine oil is leaking onto hot components. This will have a very distinct smell and should immediately set alarm bells ringing for drivers. Excessive smoke from the vehicle’s exhaust can indicate worn piston rings or valve seals. Excessive oil consumption is another clue that something is amiss with the car.
  • A fuel smell inside the car could be as simple as forgetting to screw on the car’s fuel cap correctly so this is the first thing that drivers should check. Alternatively it may mean that the vehicle’s fuel tank venting is obstructed, the engine is running too rich or there’s a fuel leak.
  • An electrical smell, like singed wires, inside the car may be a sign of damage to the vehicle’s alternator or wiring system. If this is the case drivers can also expect to see a warning light on their vehicle’s dash or dimming of its lights.
  • Drivers who detect an exhaust smell while driving may have a leak in their vehicle’s exhaust system. A faulty exhaust can be a health risk so in this instance, drivers should take their car to a garage without delay.    

In the event of any of the above, motorists should contact a reputable car mechanic such as AA Car Servicing technicians, who will come to you and service your car or an AA or SIMI approved garage.

Don’t ignore your ears

Whether driving a petrol, diesel, electric or hybrid car, motorists should instinctively know how their vehicle normally sounds. Should a strange vehicle sound be detected, drivers should look to have the problem diagnosed and rectified without delay. A well maintained car will last for hundreds of thousands of kilometers if properly maintained.

Car noises motorists should listen out for:

  • A car backfiring. This is one car sound that is difficult to ignore. When loud enough it can even sound like a gun shot. A car backfiring is indicative of a too-lean engine air-fuel mixture or severely worn valves.
  • Drivers who hear a squealing sound while driving should take their car to a garage immediately. This is a sign that your alternator belt or power steering belt may be loose or stretched to near breaking point.
  • Drivers who hear a clicking or popping reverberating from the front end of their car when turning should get their vehicle’s drive shafts (which is more likely in front wheel drive vehicles) or constant velocity joints fixed immediately. Constant clicking or droning noise from the car’s wheels while driving may mean the vehicle’s bearings are defective.
  • A metal on metal knocking sound from the vehicle’s engine that varies with driving speeds may be a sign of internal engine problems. Motorists who hear this should check the car’s oil level. In the event of overheating, motorists should switch off the engine and seek professional breakdown assistance.  

React to what you feel

  • Motorists who experience shudders when breaking their car may have a problem with their vehicle’s suspension. This is a common complaint from motorists’ who have hit a pothole when driving at speed.
  • Motorists who feel a pulling sensation while driving their car may have a tyre inflation problem.

To recap, from a safety and economical perspective, motorists should be alert to anything out of the ordinary when it comes to their car. Motorists should also carry out regular car maintenance checks and follow their car’s servicing schedule.