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Searching for odd noises
There are a few faults in the motor car where the workshop is not to be envied. Think of those which only appear sporadically. Once in the workshop, everything works perfectly. The problem only appears again when
you're at home or the car is in everyday use. How is one supposed to track down the evasive phantom?
It is similar with annoying noises. They are not necessarily sporadic, but finding out where they come from, is not always that simple. Let's start with those noises, that only occur at certain speeds. In this case, the wind
is a good starting point, e.g., from the radiator-fans, which at the moment, are not in use. If one thinks that they may be the culprit, one can secure them with a piece of wire for a short test-drive.
One could search forever for noises caused by wind. We, on the other hand, will turn our attention to the suspension. When, e.g., the springs are compressed, it places a strain on the coachwork, which can also result
in unwanted noises. Try to imagine a sheet of relatively straight sheet-metal, which is buckled in one or the other direction. Sometimes even a light tap with a hammer will alter the resonance characteristics.
Indeed, in this case two people must carry out the test-drive together, one person my even have to lay in the boot, which is in fact, not actually allowed. Wireless communication between the two testers is an advantage,
so that the stretch of road where the fault is provoked, can be driven several times if necessary. One thing is certain, this type of error cannot be found in any error memory.
At this point we come to the electronics and the dashboard. Noises that occur here can come from all posible directions. Power relays can buzz through not sitting correctly, radios can pick up disturbances caused by
the on-board network. As if that's not enough, there are also the small, hardly noticable speakers. They are well hidden and can transfers any number of noises.
You have probably, on occasion, forgotten to belt up, you may also have put a heavier bag on the passenger seat without closing the seat-belt. Some manufacturers use a speaker to remind you, some inform you that
the lights have been left on or that the ignition key hasn't been removed. This means, that the speaker is connected, throught a micro-controller with the on-board electronics, plenty of possible cold-soldering points or
other faulty contacts.
| The steering, particularly when turned to the maximum |
These are things that never happened in the past. Some people maintain, sometimes unjustly, that previously, everything was better anyhow. Whatever the case may be, you had an indicator relay and that was that! An
unusual noise was always something to worry about, regardless of whether it was just a rattle or hard and metallic. The only question was, how much is this going to cost. Nowadays it's different. Today the engine may
even complain if the air supply is not quite as it should be! 05/13
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