Specifications

Problem:
The belt drive fails as a result of the defective idler. The plastic
running surface shows signs of overheating over its entire
circumference (melting).
Cause:
The water pump is worn and seized. The back of the belt
becomes overheated because of the resulting sliding friction.
It then transfers this heat to the idler, and the running surface
starts to melt and deform. This results in a loss of tension in the
drive, causing the timing belt eventually to jump.
Solution:
The water pump should be inspected regularly to ensure that it
is in perfect condition. The pump should always be replaced at
the same time as the belt is replaced.
Overheated back
of the timing belt
Defective idler
Seized water pump
CT 1105 K1
Opel, Alfa Romeo, Fiat & Saab, 1.9 JTD
ContiTech Technical Info 38
Idler failure as a result of overheating