NOx Sensor Advice

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JamesPGUK

Active Member
Joined
Mar 25, 2018
Messages
109
Location
Sunny Lancashire
Car
C220 AMG PPlus 2015 & 2016 GLC 250 PPlus
Appreciate this is a well covered topic but grateful if a bit of advice.
66 plate GLC 250 24k used warranty 2 weeks ownership. Bought from Mb.

Do both NOx sensors need replacing at the same time? If yes is this a MB recommendation that I can reference? Will be done under warranty but will only replace the faulty one.
I recall my W205 mb dealer wanted to do both at my cost even though only one failed.
Sensor 1 seems to have been replaced now the sensor 2 has failed.

MB also said no stock of sensor and don’t know when they will be in. Amazing service! EML on for two weeks and they think it could be weeks before they get stock. Can NOx be detrimental to the car if not replaced. I suggested it won’t regen if eml is on but they said it will. I got standard if you lose power contact us.

Bottom of driver wiper blade judders on return. This is on all 3 mb cars is this common? Mb said it’s not a fault.

MB put new tyres on front because of scrubbing on the outside after 15k (I insisted before purchase). 1 week later tread 6.8 6.7 6.2 150 miles. Still under used warranty. What are the chances of the knuckles being done under warranty. I see mixed messages.
Anything else I should look out for?
Thanks
 
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If you've only had it for 2 weeks and you have issues with it,I'd throw it straight back at the dealer.
Having issues myself with my recently acquired Ml63, I initially tried getting it sorted at a well respected local indie,they didn't do what they agreed they would do,the problem still exists,so I threw it back at the supplying dealer and its now booked in at merc Northampton.

Stick to your guns,consumer law is on your side.
 
If you've only had it for 2 weeks and you have issues with it,I'd throw it straight back at the dealer.
Having issues myself with my recently acquired Ml63, I initially tried getting it sorted at a well respected local indie,they didn't do what they agreed they would do,the problem still exists,so I threw it back at the supplying dealer and its now booked in at merc Northampton.

Stick to your guns,consumer law is on your side.
Agreed it’s been back to dealer and they will do it but only one sensor. I’m convinced I’ve read both need doing at same time.

For scrubbing / crabbing I see mixed messages so I’m monitoring the tread wear. Before going for knuckles under warranty.
Good luck
 
This is a common issue with no real solution.

If a damper or spring fail, the dealer will (rightly) tell you that both sides need replacing at the same time... unless the car is still under warranty, in which case they will only replace the side that failed :doh:

Sorry but there seems to be no solution to this problem.
 
Of course if they replace one sensor and the problem still persists, they will then proceed and replace the other, but there's no way around it.
 
Appreciate this is a well covered topic but grateful if a bit of advice.
66 plate GLC 250 24k used warranty 2 weeks ownership. Bought from Mb.

Do both NOx sensors need replacing at the same time? If yes is this a MB recommendation that I can reference? Will be done under warranty but will only replace the faulty one.
I recall my W205 mb dealer wanted to do both at my cost even though only one failed.
Sensor 1 seems to have been replaced now the sensor 2 has failed.

MB also said no stock of sensor and don’t know when they will be in. Amazing service! EML on for two weeks and they think it could be weeks before they get stock. Can NOx be detrimental to the car if not replaced. I suggested it won’t regen if eml is on but they said it will. I got standard if you lose power contact us.

Bottom of driver wiper blade judders on return. This is on all 3 mb cars is this common? Mb said it’s not a fault.

MB put new tyres on front because of scrubbing on the outside after 15k (I insisted before purchase). 1 week later tread 6.8 6.7 6.2 150 miles. Still under used warranty. What are the chances of the knuckles being done under warranty. I see mixed messages.
Anything else I should look out for?
Thanks
Normally nox 2 goes faulty and i strongly advice to change the faulty one only if the money is coming from you and if under warranty then ask them to chnage both which is what they usually advise customers.
 
They will only change the one that’s failed instead of both, they told me this as as Mercedes only pay for failed parts under warranty not one that might. mine failed within three days of each other which invol two trips there it’s just the way it is.
 
Yes, I think senors aquistion module has some algorithm which includes comprison of both sensor values, and when there is some, even smaller offset/implaisibility between old and new sensor (of course there is, there sensor do 'wear' or at least dirty during their usage), and eventually accumulative error triggers a fault code. Sensor could be 'fully' functinoal but system sees it faulty since there is a difference between them.

I wonder what would happen if one just would clean the old remaining sensor, and then initialize it as a new, with truly new sensor?
 
This thread should be about HTF does such an important part of a 'prestige' car fail after just 24K miles ! ?

We can talk until the cows come home about how complex engines are nowadays , blah , blah, blah , and how they need a 'run' on the motorway for X amount of miles every now and again to 'clean them out' . All of which is true but bollock$ at the same time.

Most people who buy these cars new do not know this - and if they did they would walk away and buy something more suitable - and as for the front end crabbing/scrubbing on a RHD GLC ? another MB fail.

What ever the reasons for the OP's dilemma the dealership are not helping with the whole MB ownership experience. 2 weeks in to ownership of a 4 year old low mileage car and it has already gone sour.

I hope you get it sorted James , best of luck.
 
This thread should be about HTF does such an important part of a 'prestige' car fail after just 24K miles ! ?

We can talk until the cows come home about how complex engines are nowadays , blah , blah, blah , and how they need a 'run' on the motorway for X amount of miles every now and again to 'clean them out' . All of which is true but bollock$ at the same time.

Most people who buy these cars new do not know this - and if they did they would walk away and buy something more suitable - and as for the front end crabbing/scrubbing on a RHD GLC ? another MB fail.

What ever the reasons for the OP's dilemma the dealership are not helping with the whole MB ownership experience. 2 weeks in to ownership of a 4 year old low mileage car and it has already gone sour.

I hope you get it sorted James , best of luck.
Thanks appreciate the comments. We have 2 Mercedes and when you buy so called premium you expect things to be sorted. Apple quality is terrible if you look at the stats yet go to the shop here’s your free fix or brand new phone. I had a phone replaced 4.5 years using not of quality on a battery issue and no hassles (helps if your forthcoming with your rights). Customer service is good so the customer goes away loyal.

This will be the last MB we buy. I thought buying from the dealer would help but clearly going to be fun. Tyres will be interesting journey but collecting the evidence and I’m not shy of going to court. Put the deposit on the CCard so they can join the fun when needed. Other car has over 30 faults from new ranging from split seats (35k wear and tear lol), coolant split open (said top up could have been disastrous) fuel filter split open fuel splashing fuel in engine bay (this is with DVSA), boot lift failed, cabin noise in footwell, NOx x2 o2 x2, glow module, glow plug replacement, rattling pano roof and back of car, tyre wear front before back, all puddle lights, window switches coming off, usb failing, add blue issues the list goes on and on all low miles.
On fuel filter MB took the part for investigation via DVSA and no fault found, it’s split open inside out (lol) and won’t replace the 2 month old part. Take it back to the place of purchase. Oh ok give it me back. We can’t find it. Give me the report “no”. Replace it “no” DVSA erm your right it stinks but we have no balls. Well I have :)

Crazy no Nox sensors available. My concern I see in the forum when diesel gate software is updated not long after the NOx can trigger. New car under warranty had an update just before purchase so it does sound right because we have EML NOx. My other out of warranty car is under a recall so they perform an update and likely sensors fail again oh great. Looking forward to that conversation with dealer and DVSA.
MB has issues yet a super easy fix is dealer customer service they are so arrogant and sole intention is to take cash when they know the customer shouldn’t be paying for the work. Place we purchased from was honest can’t fault them and follow up but local dealer is horrific and they own a few near us.
 
This thread should be about HTF does such an important part of a 'prestige' car fail after just 24K miles ! ?

We can talk until the cows come home about how complex engines are nowadays , blah , blah, blah , and how they need a 'run' on the motorway for X amount of miles every now and again to 'clean them out' . All of which is true but bollock$ at the same time.

Most people who buy these cars new do not know this - and if they did they would walk away and buy something more suitable - and as for the front end crabbing/scrubbing on a RHD GLC ? another MB fail.

What ever the reasons for the OP's dilemma the dealership are not helping with the whole MB ownership experience. 2 weeks in to ownership of a 4 year old low mileage car and it has already gone sour.

I hope you get it sorted James , best of luck.
The space shuttle Challenger disastrously killed everyone on board because of an O-ring failure. Space shuttles cost a bit more than a Maybach GLS. Even with the best intentions things can fail.
 
The space shuttle Challenger disastrously killed everyone on board because of an O-ring failure. Space shuttles cost a bit more than a Maybach GLS. Even with the best intentions things can fail.
But it wasn’t a know issue 😂
 
But it wasn’t a know issue 😂
YES IT WAS

The Rogers Commission found that NASA's organizational culture and decision-making processes had been key contributing factors to the accident,[5] with the agency violating its own safety rules. NASA managers had known since 1977 that contractor Morton-Thiokol's design of the SRBs contained a potentially catastrophic flaw in the O-rings, but they had failed to address this problem properly. NASA managers also disregarded warnings from engineers about the dangers of launching posed by the low temperatures of that morning, and failed to adequately report these technical concerns to their superiors.
 
YES IT WAS

The Rogers Commission found that NASA's organizational culture and decision-making processes had been key contributing factors to the accident,[5] with the agency violating its own safety rules. NASA managers had known since 1977 that contractor Morton-Thiokol's design of the SRBs contained a potentially catastrophic flaw in the O-rings, but they had failed to address this problem properly. NASA managers also disregarded warnings from engineers about the dangers of launching posed by the low temperatures of that morning, and failed to adequately report these technical concerns to their superiors.
Ouch
 
With regard to the crabbing/tyre scrubbing, don't expect Mercedes to be able to fix this, even if they threw every new part at the issue.

You're only guaranteed chance of resolution on this tracking issue is to take the car to somewhere like wheels in motion/discuss with them the problem, then if they can get adjustable bolts they might be able to sort the alignment out; although from one of the earlier posts, it sounds like a known problem and I don't know if WIM would be able to definitely fix. However, they would be able to accurately tell you what can or can't be done about it.
 
Appreciate this is a well covered topic but grateful if a bit of advice.
66 plate GLC 250 24k used warranty 2 weeks ownership. Bought from Mb.

Do both NOx sensors need replacing at the same time? If yes is this a MB recommendation that I can reference? Will be done under warranty but will only replace the faulty one.
I recall my W205 mb dealer wanted to do both at my cost even though only one failed.
Sensor 1 seems to have been replaced now the sensor 2 has failed.

MB also said no stock of sensor and don’t know when they will be in. Amazing service! EML on for two weeks and they think it could be weeks before they get stock. Can NOx be detrimental to the car if not replaced. I suggested it won’t regen if eml is on but they said it will. I got standard if you lose power contact us.

Bottom of driver wiper blade judders on return. This is on all 3 mb cars is this common? Mb said it’s not a fault.

MB put new tyres on front because of scrubbing on the outside after 15k (I insisted before purchase). 1 week later tread 6.8 6.7 6.2 150 miles. Still under used warranty. What are the chances of the knuckles being done under warranty. I see mixed messages.
Anything else I should look out for?
Thanks
Bought a 62 Plate Merc ML at the beginning of May. A week ago I got message something like "1,700 miles before AdBlue runs out". I filled AdBlue to the brim. EML light still on. Tried all the tricks on the web to turn it off. No Go. Next day "600 miles engine won't restart". Took it to MB Oxford today. They are getting 2 Nox sensors for the end of the week. They want £1,871.52. and will have to remove exhaust. 3.8 hours
Does anyone have the part numbers for the nox sensors and the adblue tank
Mercedes want £1800+ to sort this problem
 
Bought a 62 Plate Merc ML at the beginning of May. A week ago I got message something like "1,700 miles before AdBlue runs out". I filled AdBlue to the brim. EML light still on. Tried all the tricks on the web to turn it off. No Go. Next day "600 miles engine won't restart". Took it to MB Oxford today. They are getting 2 Nox sensors for the end of the week. They want £1,871.52. and will have to remove exhaust. 3.8 hours
Does anyone have the part numbers for the nox sensors and the adblue tank
Mercedes want £1800+ to sort this problem
Ask spare parts department for quote, there you’ll see the part numbers for your car.
 

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