Glow plug failure OM624 engine

[CharlieBee]

Evening all!

My 2009 320cdi had the glow plug light on when I bought it 2 1/2 years ago. I took it to a respected indie who put a new glow plug module in it. This cured the problem for a while. By autumn of last year it started to struggle again and the light was coming back on after starting. I took it to my local guy who said that only 2 of the 6 plugs were working. He replaced all of them and that, again, cured the problem for a while before the light started to come back on again. I took it back and he said that 2 of the plugs had failed, so he replaced them under warranty. Again, the car was fine until the weather started to to turn cold recently.

I took the module off, just to check if it had actually been replaced in the first place. After checking the part number on it, it seems that it was the incorrect part. After checking the glow plugs, I have discovered that none of them work.

Would the wrong module cause the failure of all of the glow plugs or is it more likely that the wrong glow plugs may have been fitted (or both!)?

Thanks in advance

 

[W1ghty]

Evening all!

My 2009 320cdi had the glow plug light on when I bought it 2 1/2 years ago. I took it to a respected indie who put a new glow plug module in it. This cured the problem for a while. By autumn of last year it started to struggle again and the light was coming back on after starting. I took it to my local guy who said that only 2 of the 6 plugs were working. He replaced all of them and that, again, cured the problem for a while before the light started to come back on again. I took it back and he said that 2 of the plugs had failed, so he replaced them under warranty. Again, the car was fine until the weather started to to turn cold recently.

I took the module off, just to check if it had actually been replaced in the first place. After checking the part number on it, it seems that it was the incorrect part. After checking the glow plugs, I have discovered that none of them work.

Would the wrong module cause the failure of all of the glow plugs or is it more likely that the wrong glow plugs may have been fitted (or both!)?

Thanks in advance

Yes , a failed glow plug can fuse the gp module . I don’t think a failed module can fry the plugs though ?
We have the same car , I think the plugs are all 4.4v ones .
Either way I can’t see an MB Independent specialist garage getting any of it wrong .

 

[CharlieBee]

Yes , a failed glow plug can fuse the gp module . I don’t think a failed module can fry the plugs though ?
We have the same car , I think the plugs are all 4.4v ones .
Either way I can’t see an MB Independent specialist garage getting any of it wrong .

Thanks. The module I took off the car is A642 900 77 01 but when I got in touch with Mercedes, they said it wasn't the part for my car and that I needed A642 900 78 01. I wonder whether this would cause a big problem?

 

[W1ghty]

Thanks. The module I took off the car is A642 900 77 01 but when I got in touch with Mercedes, they said it wasn't the part for my car and that I needed A642 900 78 01. I wonder whether this would cause a big problem?

Sorry I can’t answer that one .

 

[vijilants]

There was an updated glow plug controller unit for the OM642. I had mine replaced on my previous C320CDI with the updated unit when i lost glow plugs.

I think the updated unit has a white back.