When you do replace them use the 61G not the 9G glowplugs, Oreillys will push the 9G as they stock it where I live and can bring the 61G's with no shipping, the ACDelco 61G's made in Germany are the best choice. You could buy Bosch glowplugs from Rockauto and get an ACDelco in the box for a few dollars more. I did not feel like dinking with one at time, so all eight were replaced..