Ad blue Euro 6 system problems

[Suelacy]

Hi
Can anybody help me please.

My car only has only done 11,000 miles, but a MB specialist says the engine looks like it has done 150,000 miles!!

It all started with an error code saying the NOX sensor had a fault.

After replacing the first NOX further errors kept occurring.

The latest error says "The flow in the EGR (cylinder bank 1) is too low. There is a general failure.

After spending £1500.00 so far and now having the latest error I am at my wits end .

The faults found and work carried out so far have been:

Replaced down stream NOX sensor as per fault code and carried out software update.

Replaced upstream NOX sensor as per fault.

Fault for low pressure EGR valve.

Carried out testes, replaced low pressure EGR valve, noted heavy contamination.

Test low and high pressure EGR systems, all operational, air mass sensor low at idle.

Check air mass sensor, heavily fouled with engine oil.

Excess oil noted in inlet track, check breathers – ok.

DPF heavily fouled, carried out regeneration of DPF, air mass now ok.

Excess oil and carbonation in inlet and EGR systems.

Excess crankcase pressure in engine.

Heavy fouling in breather system.

Requires engine investigation, suspect piston ring/bore fault.

Does anybody know what on earth is happening to my car? The main dealer want £174.00 to read the error code before they will investigate further. I can see this costing me another £2k if they just keep om replacing parts. Surely both NOX and EGRs have not needed replacing

Any ideas / advice would be greatly appreciated.
Many thanks, Sue

 

[Blobcat]

Hello and welcome,

Unfortunately your issues aren’t that uncommon... please have a search on the forum as many Nox sensor issues following software updates as well as DPF and Ad Blue issues.
Some are lucky and Mercedes cover them under warranty, others get ££££ bills

 

[Suelacy]

Hello and welcome,

Unfortunately your issues aren’t that uncommon... please have a search on the forum as many Nox sensor issues following software updates as well as DPF and Ad Blue issues.
Some are lucky and Mercedes cover them under warranty, others get ££££ bills

Hi Blobcat, thank you for taking the time to reply.
Unfortunately it all started after the 3 year warranty expired and as I have already paid £1500.00 and still have problems I just dont know what to do. Obviously MB will not accept responsibility .
I will try to find more info on this forum.
Thanks, Sue

 

[sonic]

Welcome sorry to hear about your issues. There have been cases in the past where MB have made quite a large contribution to repairs just outside warranty. Have you challenged this with MB, if you have i would certainly elevate it particularly with your low milage.
Diesel engines particularly Euro 6 with add blue do not like short journeys. Our SLC250d only does about 3-4K miles a year, but its rare any journey is under 15 miles so the engine gets hot. Just wondering about your driving style?

 

[Suelacy]

Welcome sorry to hear about your issues. There have been cases in the past where MB have made quite a large contribution to repairs just outside warranty. Have you challenged this with MB, if you have i would certainly elevate it particularly with your low milage.
Diesel engines particularly Euro 6 with add blue do not like short journeys. Our SLC250d only does about 3-4K miles a year, but its rare any journey is under 15 miles so the engine gets hot. Just wondering about your driving style?

Hi
I bought the car from my Dad after 3 years and it had only done 4,000. Probably 25 miles per week . Thought it was a good buy because of the low mileage
He leased it and had an agreed mileage of 10,000 per year, so was obviously not advised about the problems that may cause.
Its just that after changing 2 NOX and an EGR it now has a problem with the 2nd EGR. I just fear that if I get that fixed something else will be wrong. Where will it stop

 

[sonic]

Whats your driving style now, are you doing regular short journeys? If thats the case then the issues will continue, you need to buy a petrol car.
The key to Euro 6 diesel cars is no short journeys.

 

[ssheikh93]

You may be very unlucky. These cars actually need to have oil and filter changes every 5k miles. Also need a carbon clean about ones a year

 

[V6Matty]

You may be very unlucky. These cars actually need to have oil and filter changes every 5k miles. Also need a carbon clean about ones a year

That’s a new one on me, where did you find that out?

 

[ssheikh93]

That’s a new one on me, where did you find that out?

Carbon build up is bad on these cars, especially if you do short journeys. My timing chain recently went. 3-4 indies near me have all mention oil needs to be changed 5-6k miles and a good yearly carbon clean.

 

[V6Matty]

Kind of get that if your only ever doing short trips, but I think that that’s only fixing a symptom, really diesels just need to be taken on a run