Continental has identified the cause of tensioner pulley fractures on some VW, Audi, Seat, Skoda 1.4–2.0 TDI common rail, EA288 engines.

Problem
The adjustment cam on the tensioner pulley fractures during tensioning process (Fig. A).

Cause
The fastening nut is overtightened during assembly. As a result of this, the nut turns together with the eccentric cam during tensioning, subjecting it to an even greater load. This produces too much resistance, causing the adjustment cam to crack (Fig. A).

Solution
The nut must only be tightened by hand prior to tensioning. Use an appropriate tool to hold the nut securely (Fig. B and C) so that it doesn’t turn together with the cam. You now tighten the tensioner pulley by turning it clockwise until the pointer aligns with the marker notch (Fig. C). You can then finish tightening the nut.