The first step is to conduct the work of  checking the belt: During the checking work , the first task is to check  the tightness of the belt , the best way of checking is to judge  the  tightness of the belt by feeling  it ; it   is found that  the belt is obviously slacking , then   the timing  will be    in dislocation , and it  will affect the  performance of the engine , the most possible reason  for this may lie in  that the belt has been excessively stretched ,or maybe the deice of automatic  tensioning  are slacking or  seized  up, another reason may be  the spring is broken , in that case  it  has to be  replaced with  new ones. The damage of the   belt teeth:  this kind  of problem often  occurs  when  the belt is in low  tension , and  there  is some dirt  remaining  in the  indentation of the chain wheel. At this time  check should be made on the sealing of the gasket .However , if   the tension strength   provided by the tensioning device  is too big , or  if the   tension  strength is  properly provided but   the   device of tensioning  has not been  aligned , both of them may be the causes  making   the cracks  on the belt teeth and  the back of  the belt .At this  occasion  the best   way out  is to renew the  timing belt on time .When   checking  is carried out , if  the following phenomenon have been found out  such as  the   belt hardness is reduced , and there is  any wearing  corrosion ,broken  fiber, or  flaw and fracture  occurred , it indicates that the belt is broken and can not continually to be used .  it is reminded  that if the  timing  belt is broken ,  it will cause  you some unnecessary  economic losses .