What to Do When You Engine Is Trying to Send You Morse Code
If you're of a certain generation, you may remember the typewriter, an archaic invention designed to help journalists ply their trade and something that is definitely out of place today. You may remember the distinctive tapping noise and think that it is very similar to the sound emanating from underneath your car's bonnet. What is going on when you "rev" the engine and should you be worried about it?
Out Of Balance
This type of tapping noise is usually associated with an incorrect mixture of fuel and air as it enters the engine's combustion chamber. To operate efficiently, your car must receive a perfect dose of these ingredients, as they are mixed together and ignited by a spark to create the appropriate energy. When the mixture is out of balance, many problems can arise and this tapping or knocking noises may be one of them.
Usually, issues here are can be traced to poor-quality petrol within the system. Have you been buying the proper grade of fuel recently or have you been trying to save a few dollars by picking up a cheap blend? Remember, your engine is finely tuned to receive the proper fluid and it's simply not going to work properly otherwise. Also, this could cause premature combustion and a build-up of soot contamination within the chamber, which could lead to these irregularities and that tapping noise.
Contamination From The Tank
Alternatively, have you used every last drop of petrol in an ambitious attempt to cover a few miles more before refilling? If so, you may have dredged up some contamination from the bottom of the tank and this may have found its way into the combustion chamber to cause havoc. Once again, this can seriously affect the ratio of fuel to air and mess with the overall timing.
If fuel is not the issue, then you may have a mechanical problem related to timing. For this, you need a special tool to see if the alignment has "slipped" as shown by a special mark fitted to the rear of the engine. The timing light will flash in sync when it's connected properly, against the reading provided by that mark.
Finally, you may need to change the spark plugs if your car is of an older vintage. These will wear out with time and may not be able to provide the necessary ignition when called for.
If the sound of a typewriter under your bonnet is still driving you crazy, you can always take the vehicle into your friendly mechanic for a car service.