DeeJayHaitch
New Member
- Joined
- Dec 14, 2017
- Messages
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- Your Mercedes
- ML250/63/W166
Hi all,
This is my first post here, and I'm completely ignorant to anything mechanical, so you'll have to excuse me. I did search for this problem before posting here, but couldn't find anything, so hope I haven't duplicated a thread.
Anyway, onto my problem; About a month ago, the 'AdBlue low' warning and engine management lights appeared on my dash. I ordered some AdBlue, and filled up the tank with nearly 20ltrs. I started the car, but the warning was still there, and telling me the car wouldn't start in circa 500 miles. I couldn't find a way to clear the warning, so thought it may turn off once I start driving around.
I did a mix of local and motorway miles, until it got to 16 miles left and it still hadn't turned off. So now I'm starting to worry. Had a look online, and although it seemed to be a regular issue, there was no definite resolution. I had a look in the service menu, and it showed the AdBlue tank was full, so knew it wasn't the tank sensor. So now I called MB, only to be told it would need to be brought in for diagnostics - probably a familiar story. I was loathe to take a vehicle out of warranty to the dealer, but I'm new to the area (Nottingham) and in the market for a new car, so took it in as was a chance to test the dealer (Nottingham - Inchcape).
I received a call later that day informing me that both NOx sensors had failed, and would need replacing, for circa £1,100!! Of course, they had them in stock and could fit that day. After some further research and pondering, I begrudgingly agreed to the repair. A few hours later they found an issue with a thread, which they would have to call in a third party to sort. 24hrs later and I'm still waiting to hear back.
I have two questions:
1) given it seems to be a popular problem - not just with Mercs, but these AdBlue/BlueEfficiency systems in general, I've surprised not to find any threads on here, unless I'm searching wrong. Many seem to be the other side of the pond, but did come across some from the UK. Also, found this which relates exactly to my problem "26-11-2017: Report of 2013 Mercedes ML250 Engine Management Light coming on. Manual it suggested AdBlue was running low. Owner put 10 litres into the AdBlue tank. Then got a message that the engine would not restart after 800 miles (as if it still thought AdBlue was running out). After 260 miles and parking overnight the next day the engine did not start. On getting it to a Mercedes garage they told owner that diagnostics showed them the NOX sensor is showing a fault. the cost of replacing it will be close to £600. The car runs fine but the engine light is on and the dash displays check AdBlue. (Might really be a failed AdBlue heater.)" Source: https://www.honestjohn.co.uk/carbycar/mercedes-benz/ml-class-w166-2012/?section=good - however, I can't find the source of the report.
Anyone else in the same boat, or had the same issue?
2) I repeat, I'm completely ignorant and don't know the system, but what's the chance of 2 sensors failing at the same time? I'm concerned they may not have found the root cause, if there is one. Can anyone who knows the system shed any light on this?
Regards.
This is my first post here, and I'm completely ignorant to anything mechanical, so you'll have to excuse me. I did search for this problem before posting here, but couldn't find anything, so hope I haven't duplicated a thread.
Anyway, onto my problem; About a month ago, the 'AdBlue low' warning and engine management lights appeared on my dash. I ordered some AdBlue, and filled up the tank with nearly 20ltrs. I started the car, but the warning was still there, and telling me the car wouldn't start in circa 500 miles. I couldn't find a way to clear the warning, so thought it may turn off once I start driving around.
I did a mix of local and motorway miles, until it got to 16 miles left and it still hadn't turned off. So now I'm starting to worry. Had a look online, and although it seemed to be a regular issue, there was no definite resolution. I had a look in the service menu, and it showed the AdBlue tank was full, so knew it wasn't the tank sensor. So now I called MB, only to be told it would need to be brought in for diagnostics - probably a familiar story. I was loathe to take a vehicle out of warranty to the dealer, but I'm new to the area (Nottingham) and in the market for a new car, so took it in as was a chance to test the dealer (Nottingham - Inchcape).
I received a call later that day informing me that both NOx sensors had failed, and would need replacing, for circa £1,100!! Of course, they had them in stock and could fit that day. After some further research and pondering, I begrudgingly agreed to the repair. A few hours later they found an issue with a thread, which they would have to call in a third party to sort. 24hrs later and I'm still waiting to hear back.
I have two questions:
1) given it seems to be a popular problem - not just with Mercs, but these AdBlue/BlueEfficiency systems in general, I've surprised not to find any threads on here, unless I'm searching wrong. Many seem to be the other side of the pond, but did come across some from the UK. Also, found this which relates exactly to my problem "26-11-2017: Report of 2013 Mercedes ML250 Engine Management Light coming on. Manual it suggested AdBlue was running low. Owner put 10 litres into the AdBlue tank. Then got a message that the engine would not restart after 800 miles (as if it still thought AdBlue was running out). After 260 miles and parking overnight the next day the engine did not start. On getting it to a Mercedes garage they told owner that diagnostics showed them the NOX sensor is showing a fault. the cost of replacing it will be close to £600. The car runs fine but the engine light is on and the dash displays check AdBlue. (Might really be a failed AdBlue heater.)" Source: https://www.honestjohn.co.uk/carbycar/mercedes-benz/ml-class-w166-2012/?section=good - however, I can't find the source of the report.
Anyone else in the same boat, or had the same issue?
2) I repeat, I'm completely ignorant and don't know the system, but what's the chance of 2 sensors failing at the same time? I'm concerned they may not have found the root cause, if there is one. Can anyone who knows the system shed any light on this?
Regards.
