One of my glow plugs is defect, so they need to be changed. I have a A13DTE engine and there is a step by step guide here on how to change them:
https://www.youtube.com/watch?v=onMmIltMokQ&t=637s
However this is quit intricate process by removing turbo and DSP, one or two comments on this video claims that all glow plugs can be removed by using a glow plug removal socket set and only removing the oil feeder and heatshield.
Like this:
https://www.ebay.co.uk/itm/282975441040
Have someone