How to Inspect Pulleys
From BMW E34 Encyclopedia
In this section, we will cover inspection of pulleys on the M60B40 engine. The general principals apply elsewhere.
Before inspecting pulleys you must remove your V-Belt/AC compressor belt.
- If the pulley spins freely, bearing has failed. If pulley has no bearing the accessory has failed (power steering pump pulley is attached to an internal pulley within power steering pump)
- If it spins freely that means you have a power steering pump on the way out. It is highly recommended to replace the pulley.
- If it is tough to spin; it is also an indication of a failed bearing/seized pulley. You may try to clean the pulley (or do the old hit until it works trick) however, replacement is advised.
- If pulley makes grinding/whining sound while you are spinning it by hand. You must replace it.
- Spin power steering pulley located on bottom right of the oil pan, check for signs of failure described above. Attempt to move it back and forth. An only slight play is acceptable.
- Spin the alternator pulley (located on top right of the power steering pulley) check for signs of failure described above. No play is acceptable when moving it back and forth.
- Spin AC compressor pulley. It should not bind or grind at any point.
- Check the water pump pulley. There should be no play when moving it back and forth.
- Inspect idler and adjusting pulleys. The common failure indicator is grinding sound when they are spun. Both of the pulleys in question will often spin freely when failed .vs seizing.
Water Pump Bearing