Noticed a light knocking this morning as my wife pulled out of the driveway in my 95 525i. It was the first start of the day (about 45 degrees). Did not really seem to change with change in engine speed.

When she returned no knock after engine warmed up. Not sure what is causing this. Oil and filter changed 600 miles ago with oil level proper. Belts and pullies, water pump and motor mounts all within 12 months. No sure there is any issue.

TIA