What is your car trying to tell you?
Believe it or not, a car can talk to you. Those strange noises from under the bonnet or somewhere else in the vehicle all have different meanings and, if you pay attention to them, are sending you a clear message.
Jeff Osborne, Head of Automotive for Gumtree SA, says, “Those unusual sounds are a form of early warning system and you need to learn what they mean, especially if you are test driving a vehicle for purchase”.
Jeff says there are several common and obvious noises to look out for.
Loud exhaust noise while driving?
You could have a leaking exhaust pipe. Newer cars are designed to make as little exhaust noise as possible but, as a car ages, the exhaust system becomes worn and could develop a leak. This needs be checked as it affects the engine performance.
A sound like a tin full of nails being shaken under your bonnet every time you start your car?
These are called pinking sounds and could indicate that damage is being done to the piston or the valves. Possible reasons include the ignition timing being too far advanced; the car using fuel with too low an octane value; overheating; or the spark plugs having the wrong heat value. On older cars, pinking is often caused by too much carbon build-up inside the engine due to too many short trips in which case spend at least an hour on the open road every few weeks to burn away some of the carbon.
Your engine emitting tapping noises?
The valve-train components might be worn or the engine tappets are loose. This may not cause any immediate damage, but they must be reset at some point as the tappets may be too tight and cause the valves to burn. If an engine is fitted with hydraulic tappets, often these will be noisy when the engine is cold but quieten down as the engine warms up.
Clicking sounds when idling?
Your pistons could be worn in a condition known as piston pins. An immediate fix is seldom needed because the wear will take a long time to become severe enough to warrant replacement.
A light knocking sound coming from your bonnet?
Big-end bearing damage usually exposes itself as a light knocking that is more prominent when the engine is pulling or slowing down. This could be an expensive noise as it points towards an engine overhaul.
Your car squeaking when you take a turn?
A squeaking noise under the bonnet is often the result of a misaligned fan or alternator belt. The power-steering pump’s drive belt will screech on full lock if the tension is even slightly too loose.
An intense rattling or slapping noise when idling?
This could be the timing chain. This is normal on some older cars but you should seek a technician’s advice to help you decide whether you should have the chain replaced. If the engine has a timing belt instead of a chain, the noise will sound more like a slap than a rattle, but these belts usually break before they become noisy.
Osborne advises “if in doubt, check it out” because tackling a problem early can avoid a much bigger expense down the line. He also stresses the need for regular servicing of every vehicle to prolong its life and to keep it in mint condition.
Source: Gumtree