W211 E320 CDI Glow Plug Light staying on after start up

[Mar64]

Hi, I've got a W211 2004 Mercedes E320 CDI with some kind of glow plug issue.

When starting the car from cold the glow plug light comes on as usual before starting. However once it's started the glow plug light comes back on and stays on for around a minute before going out. BTW, the car always starts as normal with this issue.

I have checked the glow plugs with a multimeter and they are all ok. Next I removed and opened the glow plug relay box and found that one of the fuses had blown. So I replaced the relay box and it's also blown the exact same fuse inside the new relay box.

I assume therefore that it's a wiring issue, however I know very little about wiring. Could anyone give me a pointer as to where I should look next and what to look for?

Thanks,
Mark

 

[00slk]

Welcome.
You should really find an Indy and have the car put on the scanner, usually the best and most inexpensive way to get it sorted. You can keep buying parts and not find the cause and the scanners should get you in the right direction.

 

[Mar64]

Thanks for the advice, however I tried a Mercedes Indy before with a different issue on this car and they misdiagnosed and cost me a lot of money.

I'm interested in trying to resolve this issue myself first. As I say any help would be great.

 

[00slk]

Thanks for the advice, however I tried a Mercedes Indy before with a different issue on this car and they misdiagnosed and cost me a lot of money.

I'm interested in trying to resolve this issue myself first. As I say any help would be great.

Yes sometimes they can get it wrong, I had had the same problem and cost me dearly. I too prefer to solve the problem myself, but electrics, that's a big no no for me and I have been told by my Son that I do not touch anything on a car that has wires!!! I can set fire to any car by just replacing a fuse

 

[brianbrian]

You need to check glow plugs are O,K. If all good, then the relay.

 

[brianbrian]

You need to check glow plugs are O,K. If all good, then the relay.

 

[mattkh]

Next I removed and opened the glow plug relay box and found that one of the fuses had blown. So I replaced the relay box and it's also blown the exact same fuse inside the new relay box.
Thanks,
Mark

What are you calling the relay box.?

 

[Mar64]

You need to check glow plugs are O,K. If all good, then the relay.

I have checked the glow plugs with a multimeter and they are all ok. I then removed and opened the glow plug relay/control box and found that one of the fuses had blown. So I replaced the relay box and it's also blown the exact same fuse inside the new relay box.

I assume therefore that it's a wiring issue, however I know very little about wiring. Could anyone give me a pointer as to where I should look next and what to look for?

 

[Mar64]

What are you calling the relay box.?

glow plug relay/control box. Part number is 0285454032

 

[Chloe87]

Hi,
I just got my 2007 A 160 CDI two weeks ago, I am having a similar thing. It just started doing this on Wednesday after it went in to check the parking sensors. No fault codes were found at all, then when I collected the car, the coil symbol went out quickly, I started the car and it came back on, and now does this every start from cold and stays on for around a minute, maybe less before going out.
With the ignition on the symbol lights up and goes out straight away, but then on start up, turns over and starts absolutely fine it comes back on?!

I do have 3 month warranty from the seller, but I am new to diesels, Mercedes and glow plugs. Any help/advice would be greatly appreciated before I phone the seller and get to a garage.

thanks

 

[Blobcat]

Hi,
I just got my 2007 A 160 CDI two weeks ago, I am having a similar thing. It just started doing this on Wednesday after it went in to check the parking sensors. No fault codes were found at all, then when I collected the car, the coil symbol went out quickly, I started the car and it came back on, and now does this every start from cold and stays on for around a minute, maybe less before going out.
With the ignition on the symbol lights up and goes out straight away, but then on start up, turns over and starts absolutely fine it comes back on?!

I do have 3 month warranty from the seller, but I am new to diesels, Mercedes and glow plugs. Any help/advice would be greatly appreciated before I phone the seller and get to a garage.

thanks

One or more of the glow plugs have failed if the warning light comes back on after starting. Take it back and get the supplying dealer to rectify it

 

[Frontstep]

I have checked the glow plugs with a multimeter and they are all ok. I then removed and opened the glow plug relay/control box and found that one of the fuses had blown. So I replaced the relay box and it's also blown the exact same fuse inside the new relay box.

I assume therefore that it's a wiring issue, however I know very little about wiring. Could anyone give me a pointer as to where I should look next and what to look for?

With a glowplug gone they usually start a little bit lumpy and you get some unburnt fuel coming out of the exhaust you could use your multimeter to check for volts at the plug end after replacing fused link to check wiring.

The glow plug control unit is on here somewhere with its top off, have a search.

 

[andrew056]

If you're blowing fuses inside the relay that would seem to indicate that one of the glow plugs is shorting to earth . Or if the plugs are really OK then it must be the wiring from the relay to the plugs that's shorting out.

 

[Mar64]

If you're blowing fuses inside the relay that would seem to indicate that one of the glow plugs is shorting to earth . Or if the plugs are really OK then it must be the wiring from the relay to the plugs that's shorting out.

I have checked the glow plugs with a multimeter and they are all ok. So as you say, I assume it's the wiring from the relay to the plugs that is the issue. I will look into this and report back. Thanks