Timing belt changes: patience is a virtue
Many car owners realise the potential dire consequence of timing belt failure. Belt breakage tends to mean a wrecked engine and a repair bill totalling many thousands of pounds.
For this reason, anything that could fail and reduce timing belt life is changed as well. This includes pulleys, tensioners and, sometimes, the engine water pump.
Yet, as so few car owners replace the timing belt kit themselves, it is easy not to appreciate that incorrect fitting can also have catastrophic consequences. The belt’s tension is especially critical. Should the belt be set too loose, its teeth can jump on the pulleys. Should it be too loose, the belt’s teeth can be ripped from the belt structure. Either situation can cause terminal engine damage.
Many modern engines possess automatic tensioners (pictured), which indicate the optimum belt tension. Yet, tensioner accuracy relies on the engine being at room temperature. Even if the engine is slightly warmed, the required belt tightness could be set incorrectly. Unfortunately, not every technician is aware of this factor.
Therefore, consider that dropping a car off at a garage in the morning for a timing belt kit change and expecting to collect it several hours later is an unrealistic expectation.