GM Service Manual Online
For 1990-2009 cars only

Condition

Causes

Groaning or Growling Noise in the Steering Pump

    • Grounded power steering lines
    • A scored pressure plate, thrust plate or rotor
    • A worn cam ring
    • A low pressure relief reservoir cap
    • Restricted fluid lines (high back pressure)
    • Air ingestion in the return line
    • A damaged flow control valve
    • Low fluid level
    • Loose pump mounting bolts

Rattle Noise in the Steering Pump

    • A damaged pump rotor
    • Damaged vanes
    • Damaged pump bearings

Swishing Noise in the Steering Pump

A damaged flow control valve

Whining Noise in the Steering Pump

    • A scored pump shaft bearing
    • A scored pressure plate or thrust plate
    • A damaged cam ring
    • A damaged rotor
    • Damaged vanes