I own a mercedes sprinter 313 cdi, bit worried about the glow plug light remaining on even though the engine has started and stays on at all times. Can anyone advise me what it could be.

Mark Wood, October 2007

it stays on to let you know you have a fault with one or more heater plugs,,,when heater plugs are replaced it should go back to normall,,,but still best to check them first, one way to check heater plugs manually with out using a diagnostic machine, is to remove what ever is needed to get at the heater plugs and also remove the wires conected to them, leave the plugs still in the cylinder head, run a live wire form the battery and brush the wire against the contact of the heater plug you will see little sparks if the heater plugs good and see nothing if its dead,,,,also run the engine up to normall temp before removing heater plugs as it will give you a better chance of removing them with out snapping

garthy, November 2007