Currently looking at early W205 C220d estates (so 64/15/54 plate around 60-70k) and I've been warned about numerous issues with the SCR/AdBlue system - the issues I'm told about are blocked AdBlue injectors, failed AdBlue tank heater elements, leaking AbBlue feed lines and failing Nox sensors. Is there anything I should do once I get the car to try and prevent future issues? 2 things I've seen advice on is removing the AbBlue injector to check/remove any urea crystalisation and also using a cleaner additive such as Forte AdBlue crystal preventor.
Diesel SCR/AdBlue issues: prevention and fixes
- Thread starter cws196
- Start date
- Joined
- Jun 24, 2008
- Messages
- 48,305
- Location
- London
- Car
- 2022 Hyundai IONIQ 5 RWD / 2016 Suzuki Vitara AWD
This may not be what you want to hear, but I would avoid any car fitted with the AdBlue system. The one's on MB cars are also particularly expensive to fix when they wrong. I would strongly recommend buying a petrol car instead. The pre-facelift W205 we're equipped with the 2.0L M274 Turbocharged engine, which is a good unit. Good luck with your search.
rf065
MB Enthusiast
- Joined
- Jun 8, 2007
- Messages
- 5,329
- Location
- Grossbritannien
- Car
- SLC300 - C250d Estate 4 Matic & Z900rs
In years to come, we will all look back at AdBlue systems and say, "what were they thinking?"
- Joined
- Feb 29, 2020
- Messages
- 880
- Location
- Sittingbourne, Kent
- Car
- W221 S350L, R231 SL350 (both sold) & SL400 (current)
"In years to come" read "today"
colinallcars
Active Member
- Joined
- Jul 17, 2007
- Messages
- 972
- Car
- B180, SLK 230
If warranty is a concern then don’t buy Mercedes. Used car warranties from BMW and Lexus are far more comprehensive.
W1ghty
MB Enthusiast
The Tier 1 from MB is pretty comprehensive , I don’t have any knowledge of the other brands
- Joined
- Feb 8, 2007
- Messages
- 20,520
- Location
- Portsmouth, Hampshire.
- Car
- E55K SL500 E250X2 Smart44 Brabus Track car E450Cabriolet X350 Pick up
I would avoid adblue as much as you can. Expensive to fix, doesn't work properly flawed in every respect.
Skd884
MB Enthusiast
- Joined
- Sep 13, 2017
- Messages
- 3,937
- Car
- i3
Simple solution - buy a petrol car.
CaptainPugw4sh
New Member
Have to agree with every comment here. As a newbie to this forum and to Mercedes ownership, (came from a Volvo with 274K mls and not a days problem to C class at 50K mls) I would say steer well clear of anything to do with the ad-blue system. had my car second hand in October last year. EML light came on within 3 weeks so luckily in warranty period.
Diagnosed with Ad blue system problems in tank (not measuring levels unless engine warm), NOX sensor, EGR valve and mass flow sensor.
Just got half of the job done last week due to shortage of parts in UK and bill for just the NOX sensor, diagnostics and MF sensor is over £1300.00. Expect the rest to come in at around £2K, but a further 2 months before parts available.
Really has left a bad taste in my mouth as far as Mercedes are concerned and seriously considering going back to Volvo.
Tattmaylor
Active Member
My e220d has been in the garage for the last three weeks with an Adblue leak. They’re saying the parts aren’t UK stock, so having to order from Germany, and at a cost of £520 (for two hoses! - I’m presuming they’re made out of gold!!) but only one part arrived last week, and just called them to find out what’s happening and still no sign of the other part. My advice would be to avoid Adblue Merc’s like the plague.
Tattmaylor
Active Member
I ended up taking mine back to Mercedes. The independent garage replaced the leaking Adblue lines (for £815) but the nox sensor has also failed, so I got the warning message again. Merc reset the limit and turned the warning off and since then it’s been fine. New nox sensor is £520ish fitted. I’ll be selling my e class once this is fixed and going back to petrol.
I have been sat in independent merc garage for 6 hours now. They have had £4500 off me in last 3 mo ths and still not fixed
I Think i might have to go to the main dealer.
As soon as its done its going and i am going petrol same as you just so frustrated as between 2 garages 7k and still not fixed
I Think i might have to go to the main dealer.
As soon as its done its going and i am going petrol same as you just so frustrated as between 2 garages 7k and still not fixed
Tattmaylor
Active Member
What have they done so far to charge so much? I’d be asking for a refund if it hasn’t been fixed. Hindsight is a wonderful thing but when I did go to the Merc garage they were quite rude about me not taking it to them in the first place. My independent garage claim to be Merc specialists so that’s why I used them.
Did the mercedes reset the limit rather than replace the sensor
they said DPF first
EGR
mass flow sensor
Adblu injector
Filter
Nox sensors
Adblu injector again
Adblu pump
After each fix the light came on again in less than a mile. Almost like they were chasing it around 7k so far
Tattmaylor
Active Member
Merc have reset the engine management light and low Adblue/mileage limit warning, which hasn’t re-appeared in the last week, but they couldn’t guarantee when it would re-appear.
Sounds like the garage you are using are just going through piece by piece to find the problem. I’m no mechanic, so not sure which parts would show up on a diagnostic test but you’d think they’d have found the issue straight away. Although reading over the forums there just seems to be so many Adblue issues.
Is it too late for webuyanycar?
Sounds like the garage you are using are just going through piece by piece to find the problem. I’m no mechanic, so not sure which parts would show up on a diagnostic test but you’d think they’d have found the issue straight away. Although reading over the forums there just seems to be so many Adblue issues.
Is it too late for webuyanycar?
I had a buyer at 10k before the light came on
Tattmaylor
Active Member
Wonder if it’s worth taking to Merc then and asking them for a proper diagnostic. Or see if they can reset the light and get rid before it comes back.
Adblue has really put me off any diesel now.
Adblue has really put me off any diesel now.