Timing Belt: Inspection

Closely inspect the belt. If the following problems are evident, replace the belt with a new one.
1. Hardened back surface rubber, back surface glossy. Non-elastic and so hard that even if a finger nail is forced into it, no mark is produced.
  
  Fig 1: Checking Timing Belt (1 Of 4)
  Courtesy of KIA MOTORS AMERICA, INC.
2. Cracked surface rubber
  
  Fig 2: Checking Timing Belt (2 Of 4)
  Courtesy of KIA MOTORS AMERICA, INC.
3. Side of belt badly worn
  NOTE: A belt in good condition should have clear-cut sides as if cut with a sharp knife.
  
  Fig 3: Checking Timing Belt (3 Of 4)
  Courtesy of KIA MOTORS AMERICA, INC.
4. Teeth badly worn
  Initial stage:
  
  Canvas on the load side of the tooth flank worn (fluffy canvas fibers, rubber gone and color changed to white, unclear canvas texture).
  
  Last stage:
  
  Canvas on the load side of the tooth flank worn down and rubber exposed (tooth width reduced).
5. Missing tooth
Fig 4: Checking Timing Belt (4 Of 4)
Courtesy of KIA MOTORS AMERICA, INC.
If backlash or an irregular noise is observed when rotating the pulley, replace the timing belt tensioner and idler pulley.

Fig 5: Checking Timing Belt Tensioner

Courtesy of KIA MOTORS AMERICA, INC.