NOX System Issues ?

[Tinkerbelll]

I am new to forum so forgive me if I am posting in the wrong place. Has anyone any knowledge regarding the NOX System, I am a very low mileage user and I have had the sensor replaced now 3 times . When I purchased the car they knew I was a low mileage user as my previous car was 8 years old and 17,000 on the clock.

Seriously thinking of selling it on as when it comes out of warranty in 6 months time I have been told with my mileage I would have to have the sensor replaced twice a year ( I am currently on 3500 miles am I being fobbed off ?

 

[malcolm E53 AMG]

Welcome!

I don’t know about your NOX sensor situation but you would certainly be better off with a petrol car at that mileage pa. I cover about 4K miles pa in my E350cdi but it is pretty much reserved for longer runs interspersed with shorter journeys but I do make sure that if a DPF cycle starts I extend the run until the process has finished. Unfortunately there is no dash light to indicate that a regen is taking place which would help a lot of people but manufacturers would be pilloried if they fitted one for encouraging more pollution by extending a journey

You should have been advised better when you purchased the car but that’s another story and as you say you either trade it in or change your driving routine to include a long run every month

 

[Jim2]

Paradoxically Malcolm... IF there were a warning light fitted, and the cars were driven until the regen was complete..then the vehicle would be running cleaner after regen, and producing less NOX. Do you know if there is anyway ( sensor or something else, ) that could be fitted aftermarket which would tell you that a regen is taking place, aside from when you stop the vehicle mid regen, and there is still activity going on under the bonnet?
Best Regards, Jim2.

 

[malcolm E53 AMG]

It would have been easy enough for the manufacturer to fit a DPF regen indicator lamp into the dash much the same as the glow plug lamp as a forced regeneration is controlled by the ECU from information provided by pressure sensors fore and aft of the DPF.

On my car you can tell when a regen is taking place, the exhaust note changes and the tickover raises to 800rpm (600rpm normally) until completed, I would say the process takes on average about 15 minutes from start to finish.

I don’t know of any aftermarket kits for providing an indication of a regen commencing unfortunately

 

[SRE]

Hello Tinkerbelll and welcome.

I am surprised the sensor has failed that many times but I definitely think you need to look at trading it in for a petrol model. The emissions systems on modern diesel engines do not suit low mileage use and being forced to take regular long journeys somewhat defeats the eco-friendly intentions.

 

[LostKiwi]

I fail to see how sensor failure can be related to mileage per annum. I get DPF sensitivity to driving patterns but can't see how a sensor would be affected.

 

[dabsline]

I am new to forum so forgive me if I am posting in the wrong place. Has anyone any knowledge regarding the NOX System, I am a very low mileage user and I have had the sensor replaced now 3 times . When I purchased the car they knew I was a low mileage user as my previous car was 8 years old and 17,000 on the clock.

Seriously thinking of selling it on as when it comes out of warranty in 6 months time I have been told with my mileage I would have to have the sensor replaced twice a year ( I am currently on 3500 miles am I being fobbed off ?

 

[dabsline]

My 2 1/4 year old C250d is on its 3rd nox sensor and it has 23k on it [warranty jobs] i had a diesel as i drive down to Spain every year but i am concerned when my warranty expires

 

[malcolm E53 AMG]

Sounds like MB have an issue with the current generation of NOX sensor probably due to the introduction of ADBLUE, sounds more than just a bad batch

 

[LostKiwi]

This definitely sounds like more than a driving profile issue and I'd go for a problem in the sensor or design.

 

[Tinkerbelll]

well I went and looked at a petrol car today , now gotta decide if I sell and buy or part Ex , but defo lost my confidence in keeping my present car after reading all the above, appreciate all your replies and input, sounds like to me, someone's gonna get a bargain at my expense, and the flipping car sales rep who ill advised me just to make a sale and get his sales targets on track !! Grrrr

Thank you again for taking time to reply to me

 

[LostKiwi]

How many sensors can you buy for the depreciation?

 

[Tinkerbelll]

Oh trust me I have been down that road but I wanted a car to see me out for at least 8 years like my last one,( and had no problems what so ever with it ) but its the inconvenience of having to put it into the garage every 6 months and that's just one sensor, what if the next one starts playing up ? I think I would prefer to sell whilst I have warranty left , at £500 a pop and that's this years costs , na lost all faith in it, will always now be worrying whens it going to let me down. Do it now whilst I have the money to be able to buy what I want rather than wait a few more years get less for car and possibly not have the spare cash to buy another. Go on say it ... I'm nuts LOL

 

[SRE]

It makes sense to me. It's not the financial implications, it's the confidence in the vehicle.

 

[malcolm E53 AMG]

Not at all, the vehicle doesn’t suit your needs and it’s unreliable, not much enjoyment in that

 

[LostKiwi]

Something to bear in mind is all MB parts have a 12 month warranty. You shouldn't have too many costs involved.
The second thing is there are lots of issues on the web regarding NOx sensors with some failing in as little as 1000 miles!
This does smack of a design flaw as opposed to anything you're doing.

 

[Scoob]

Something to bear in mind is all MB parts have a 12 month warranty. You shouldn't have too many costs involved.
The second thing is there are lots of issues on the web regarding NOx sensors with some failing in as little as 1000 miles!
This does smack of a design flaw as opposed to anything you're doing.

I was told MB parts have a two year warranty, not one. This was true of the headlamp I had replaced (mostly under warranty) as well as the two wheel speed sensors I had replaced outside of warranty. If any of those parts failed again, unless through damage, then I'd expect it to be replaced under said two year warranty.

Note: the headlamp was done by a main dealer and the sensors at an independent, and both were consistent regarding the warranty period being two years on MB parts.

As an aside, I too do no more than about 4k a year, but generally slightly longer runs usually. That wasn't the intent when I bought the car, I was going to be doing a 50+ mile round trip a day, but things changed. My car is an older Euro 5 car, so no adblue or whatever it's called.

Note: I've been doing more shorter (5 mile) trips of late and, other than an MPG reduction, things seem ok. I have still done the odd longer run from time to time though, so that's likely quite relevant.

Scoob.