Annoying dash light.

[JohnDavies]

Hi all, i have a 2003 ML270 cdti and i have the glow plug light coming on and staying on for about half a mile. This happens everytime i start the engine wether or it is hot or cold. What should i be looking at here,glow plugs/sensor? Engine runs perfectly but this light is beginning to annoy me now. Thoughts/suggestions please as to how to correct it. Thank you.

 

[Larkone]

New glow plug relay

 

[JohnDavies]

Thanks for that Larkone, getting it in for a diagnostic check on wednesday but i suspect you have hit the nail on the head.

 

[Deleted member 6183]

I've had the same for at least 2 years, takes about 2 seconds longer to start on the coldest mornings.

 

[JohnDavies]

Thanks for that Doc. I shall get it fixed though.

 

[Deleted member 6183]

Thanks for that Doc. I shall get it fixed though.

Good idea, it might be worth having a chat with your mechanic first though. When I mentioned it to my hut 2 years ago he said to leave it as they can cause more problems pulling them out than leaving them.

 

[JohnDavies]

It's going in on Wednesday, i have two good boys who know their stuff so i shall let them have a look. I shall update my thread on any developments.

 

[wu56Shoozz]

When was the last time Glow plugs were changed? Maybe worth investing in a set.. they're cheap enough..

 

[JohnDavies]

When was the last time Glow plugs were changed? Maybe worth investing in a set.. they're cheap enough..

Yup, i intend to get a set fitted, cannot complain because this car has been absolutely brilliant, mind you i have looked after it.

 

[HITECH]

I had this with my C220 CDI when i bought it 3 years ago. I replaced the glow plugs. Problem still persisted. All it is is a fuse or 2 inside the relay module that blow. The relay module is a sealed unit but is easily cut open to re-solder the fuse/s that has blown. Ive seen instances where people took it to a mercedes dealer and even the dealer said after a star scan that the glow plugs need changed and the module is ok when that is not the case. Mercedes STAR is specifically for Mercedes cars. But it is not the be all and end all that some people believe. When you get to know your own car you follow your gut and either do all the work on it yourself or if you get somebody independent to do work on it then make sure you use the same person all the time. The problems arise when too many mechanics with different ideas work on your car.

 

[JohnDavies]

I had this with my C220 CDI when i bought it 3 years ago. I replaced the glow plugs. Problem still persisted. All it is is a fuse or 2 inside the relay module that blow. The relay module is a sealed unit but is easily cut open to re-solder the fuse/s that has blown. Ive seen instances where people took it to a mercedes dealer and even the dealer said after a star scan that the glow plugs need changed and the module is ok when that is not the case. Mercedes STAR is specifically for Mercedes cars. But it is not the be all and end all that some people believe. When you get to know your own car you follow your gut and either do all the work on it yourself or if you get somebody independent to do work on it then make sure you use the same person all the time. The problems arise when too many mechanics with different ideas work on your car.

Thanks for your comments,appreciated.

 

[Petrol Pete]

The glow plug light has stayed on pretty much all the time on my scabby old 1996 Iveco van. Iveco bloke told me to ignore it as the engine hasn't got glow plugs ! there is one heater plug in the intake of the throttle body that is only really required below -15'C . Had the van more than 12 years now and it sometimes stands for 4 months at a time (I really must get rid of it) but once the battery is charged up it starts after less than 2 revolutions of the crank. But had glow plug issue on car with straight 6 BMW engine and it took for ever to crank it into life until all six glow plugs were changed.

 

[JohnDavies]

The glow plug light has stayed on pretty much all the time on my scabby old 1996 Iveco van. Iveco bloke told me to ignore it as the engine hasn't got glow plugs ! there is one heater plug in the intake of the throttle body that is only really required below -15'C . Had the van more than 12 years now and it sometimes stands for 4 months at a time (I really must get rid of it) but once the battery is charged up it starts after less than 2 revolutions of the crank. But had glow plug issue on car with straight 6 BMW engine and it took for ever to crank it into life until all six glow plugs were changed.

Yup Pete, my dash glow light goes out pretty quickly so not much to worry about but i am having it checked out on Wednesday so will see what crops up. I just find that any dash light needs sorting but i am just an old natter can.

 

[Petrol Pete]

Agreed, you can not ignore lights that pop up on your dash.

 

[Rich H]

Just put a bit of tape over it.

 

[JohnDavies]

Just put a bit of tape over it.

Perish the thought !!!

 

[topdown]

Perish the thought !!!

Usually a single glow plug will have failed, like a light bulb and this causes the glow plug controller to short out. This causes the bad starting. Replacing the controller sorts the bad starting. Then the faulty glow plug needs to be identified and replaced. This can be a problem if it is ‘coked’ in and if it does not release at the removal torque, then there is a risk if the plug breaking off. CAUTION.

Star machine / carsoft II will confirm the glow plug fault but sometimes will miss the controller.
Once the controller is replaced the starting will be near normal but the glow plug warning will come back on for 60 seconds indicating a glow plug failed.

 

[JohnDavies]

Usually a single glow plug will have failed, like a light bulb and this causes the glow plug controller to short out. This causes the bad starting. Replacing the controller sorts the bad starting. Then the faulty glow plug needs to be identified and replaced. This can be a problem if it is ‘coked’ in and if it does not release at the removal torque, then there is a risk if the plug breaking off. CAUTION.

Star machine / carsoft II will confirm the glow plug fault but sometimes will miss the controller.
Once the controller is replaced the starting will be near normal but the glow plug warning will come back on for 60 seconds indicating a glow plug failed.

Thanks for that Topdown, car goes in tomorrow and i am expecting to having to replace all the glow plugs and fit a new glow plug relay. Happy days a?