i have a c class cdi w203, and lately it started doing something strange when i start it up in the morning, robably cause it'll still be cold.
i turn the ignition, wait for the glow plug light to go off, as usual, then when i start it up, after a few seconds, the light comes on again and it stays on for exactly 1 minute, (i timed it).
after that it goes off and everything is normal, it wont do it again during the day.
the car starts like clockwork, no hesitation whatsoever.
any idea why the light keeps coming on in the morning after i start the car please?

 

One of your glow plugs is gone,the car will still start with 3 functioning .When you replace the glow plugs replace all four as they are all the same age and are liable to go at any time.This job is not really a D.I.Y job because you need to know what to torque your new plugs to and you may have difficulty removing the old plugs,I got a mechanic to do this.

 

thanks diarmaid, i replaced all four glowplugs at my local dealer and the light doesnt come on any more!