One problem related to engine has been reported for the 1999 Mercedes Benz CLK430. The most recently reported issues are listed below.
Failed crankshaft position sensor left my car dead in very heavy highway traffic during rush hour. The crankshaft position sensor is notoriously failure-prone on the 8-cyl mercedes models. This is obviously (from the number of complaints) a defective part and needs to be recalled right away. Failure of the crankshaft position sensor renders the car immediately and suddenly immobile. This is a potentially life threatening defect.