C270 glow plugs ?

[Old Merc]

02 C270 with 85K on the clock.

Hi Guys, Starts on the button no problem,but,the glow plug light stays on for about 30 to 60 seconds either when cold or red hot ?
No other warning light on,dash info says "no malfunctions".

I`ve been told its a duff glow plug,as far as I know they all are the originals. is that correct? if so I will fit five,what sort of job is it?

[ZX10R NIN]

As long as it comes out smoothly you'll be fine & yes you can replace just the one.

[steve-V8s]

You should be able to check the DC resistance of all the glow plugs with a multi meter, they should all be a very similar fairly low resistance reading. If just one is markedly different that should reveal something. I understood they could be rather challenging to remove but have not actually tackled the job.

On the C350, which I think is basically the same engine my glow plug problems turned out to be the controller not the plugs themselves, they all measured very similar values. After cutting the top off the controller and digging out the pcb the broken wire was obvious and easily repaired. As with most things that have failed, if they had spent another 4p and some thought on the build it would have lasted rather longer.