Help please! - 2021 New GLA DPF regeneration problems/issues... reject the car?

OP
R

roryg

Member
Joined
Jun 10, 2021
Messages
13
Reaction score
8
Your Mercedes
GLA 2021 200d AMG Line Exec
  • Thread Starter
  • Thread starter
  • #21
Wife normally fills up at the local Sainsbury's - last tankful was Costco though.
 

Tony Dyson

Senior Member
Joined
Aug 26, 2018
Messages
4,038
Reaction score
2,585
Location
God's Country
Your Mercedes
2014 C 220 CDI W204 OM 651
The OP said, "continues to inject fuel into the exhaust system"
A popular misconception, I too had images of a 5th injector somewhere in the exhaust system upstream of the DPF when first reading up on the subject, but could never find it in a manual or under the bonnet, all became clear when I read the MB OM651 System Description doc I referred to in my previous post, I think it's important to understand this process with a view to evaluate the symptoms of overheating, burning smells, and a bonnet that is "Hot to touch" below is another excerpt from the same document which details how the exhaust temperature is raised to trigger a regen, there are three modes of fuel injection, pre, main and post: I hasten to add this is a system description of the OM 651 Engine, others will I've no doubt vary.

Post injection
The CDI control unit initiates up to two post injections following on from the main injection.
The first post injection serves to increase the exhaust temperature, which supports the conversion process for exhaust components in the oxidation catalytic converter. The second post injection is performed depending on the load condition of the diesel particulate filter (DPF). This further increases the exhaust temperature and triggers the regeneration process in
the DPF. The particles in the exhaust are subsequently burnt.


This being the case, I would expect the engine's cooling and lubrication systems to handle the additional heat created by the two post injections as design, the additional heat is designed to pass through the system and create heat in the exhaust components, not in the engine bay.
Typically when my car regenerates the exhaust temperatures will rise to just below 700° C and the dash thermostat may simply rise and fall a few degrees around normal, hardly noticeable! the regen process is designed to be passive, you shouldn't know it's happening!

What you're describing is just very wrong and in your shoes, if you still have the window of opportunity to return the vehicle for a full refund, I would take advantage before it closes, this is a new car!
 
OP
R

roryg

Member
Joined
Jun 10, 2021
Messages
13
Reaction score
8
Your Mercedes
GLA 2021 200d AMG Line Exec
  • Thread Starter
  • Thread starter
  • #23
My wife usually fills up at the local Sainsburys but last time it was Costco - should that make a difference? It's just diesel, no?
 
OP
R

roryg

Member
Joined
Jun 10, 2021
Messages
13
Reaction score
8
Your Mercedes
GLA 2021 200d AMG Line Exec
  • Thread Starter
  • Thread starter
  • #24
The OP said, "continues to inject fuel into the exhaust system"
A popular misconception, I too had images of a 5th injector somewhere in the exhaust system upstream of the DPF when first reading up on the subject, but could never find it in a manual or under the bonnet, all became clear when I read the MB OM651 System Description doc I referred to in my previous post, I think it's important to understand this process with a view to evaluate the symptoms of overheating, burning smells, and a bonnet that is "Hot to touch" below is another excerpt from the same document which details how the exhaust temperature is raised to trigger a regen, there are three modes of fuel injection, pre, main and post: I hasten to add this is a system description of the OM 651 Engine, others will I've no doubt vary.

Post injection
The CDI control unit initiates up to two post injections following on from the main injection.
The first post injection serves to increase the exhaust temperature, which supports the conversion process for exhaust components in the oxidation catalytic converter. The second post injection is performed depending on the load condition of the diesel particulate filter (DPF). This further increases the exhaust temperature and triggers the regeneration process in
the DPF. The particles in the exhaust are subsequently burnt.


This being the case, I would expect the engine's cooling and lubrication systems to handle the additional heat created by the two post injections as design, the additional heat is designed to pass through the system and create heat in the exhaust components, not in the engine bay.
Typically when my car regenerates the exhaust temperatures will rise to just below 700° C and the dash thermostat may simply rise and fall a few degrees around normal, hardly noticeable! the regen process is designed to be passive, you shouldn't know it's happening!

What you're describing is just very wrong and in your shoes, if you still have the window of opportunity to return the vehicle for a full refund, I would take advantage before it closes, this is a new car!
Thanks for the info - yes, I was under the impression that I shouldn't even know what's happening under the bonnet - it should just take care of itself. But the dealership are rejecting my rejection of the car(!) as they say there is no fault. Unless they can prove a fault I cannot reject the car, even though every fibre of my being is screaming at me to do so. I know there is something wrong. Impossible to get them to admit it. So what can I do now?
 

malcolm E53 AMG

Senior Member
Joined
Aug 21, 2005
Messages
6,993
Reaction score
4,597
I never use supermarket fuel (just a personal choice) cleaning additives especially for running a diesel are important IMO and there has always been a debate as to whether these are added to the cheaper fuels.
As regards the car unless it’s using a lot of fuel I’d live with it it’s under warranty and the fault should manifest itself at some point. As you’ve found out garages operate on fault codes nowadays and unless something is obviously hanging off/broke they won’t do anything speculatively - they’ve checked the car over and are happy with it
 

Jason63

Senior Member
Joined
May 28, 2020
Messages
85
Reaction score
61
Your Mercedes
C63 AMG
Based on what you are saying about the types of journeys you do it does seem likely you do have a problem with the car. It could be something like a faulty or blocked pressure sensor or a faulty temperature sensor. Because these sensors will report a range of values in normal operation when they go bad they don't always generate a fault code.

An experienced technician will be able to look at the sensor values and spot something that doesn't look right. Often that is beyond main dealers though...You may have to reject the car to force the issue.

The problem with failed regens with this type of regen (with the additional injection cycles) is that some diesel always get past the piston rings. The engine oil level will rise and the engine oil will be diluted with diesel. Diesel is not a good lubricant. It'll take a number of failed regens but the oil level can rise significantly.
 

Nickhgard

Senior Member
Joined
Jul 11, 2020
Messages
71
Reaction score
55
Your Mercedes
V220d
I belive that if you buy a car brand new you should be able to just add fuel and go (and maybe oil once in a while). Unless you've bought a performance car, any fuel commercially available should be good enough. There should be no need to know about additives / dpf's etc. IMO they should either ban diesel vehicles (apart from lorries/buses) or let them have bad stuff in the exhaust. This in between eur6 standard we've got at the moment clearly isn't working for the consumer. So many forums would be a lot quieter if it weren't for Dpf's.

Yes, I would push to reject the car. If possible change for a petrol one.




Sent from my VOG-L09 using Tapatalk
 

richlumb

Senior Member
Joined
Jun 5, 2020
Messages
510
Reaction score
504
Your Mercedes
GLC 350d
My wife usually fills up at the local Sainsburys but last time it was Costco - should that make a difference? It's just diesel, no?
Lot of debate about that one but from my personal experience of owning 3 Mercedes diesels I’ve only ever run them on premium fuel and never had any form of DPF issues (not even a warning of having to do a burn run) I have on occasion had to fill up at Sainsbury’s and the car smelt like a dirty old wagon ! I’d certainly give it a try on running on premium fuel
 

malcolm E53 AMG

Senior Member
Joined
Aug 21, 2005
Messages
6,993
Reaction score
4,597
Lot of debate about that one but from my personal experience of owning 3 Mercedes diesels I’ve only ever run them on premium fuel and never had any form of DPF issues (not even a warning of having to do a burn run) I have on occasion had to fill up at Sainsbury’s and the car smelt like a dirty old wagon ! I’d certainly give it a try on running on premium fuel
Yes, I find Esso runs cleaner than BP, can’t comment on Shell
 

bladecrazy

Senior Member
Joined
Jun 2, 2020
Messages
447
Reaction score
390
Location
bolton
Your Mercedes
tesla model 3 performance /honda cd175/w123 300d gertrude.
with the mileage your doing a regen should be no problem, my 14 plate does the regen in 10mins and always has.
 

JBell

Senior Member
Joined
Dec 9, 2011
Messages
14,845
Reaction score
7,186
Location
Torquey
Your Mercedes
C350 CDi Estate (GAD Edition)
Big question is, can I insist it is faulty because it is not completing a regen? Even having 18 and 23 minutes to do so?

No, the Regen takes as long as it takes depending on the level of soot clogging it. You should notice the revs dropping on idle when it does it and the engine note changing too.

The Regens haven't failed, you have just stopped them from being completed by turning the car off.

I suggest an "Italian Tune up" for at least 45 mins each way
 

Jim2

Senior Member
Joined
Jan 18, 2018
Messages
1,978
Reaction score
1,679
Your Mercedes
1st Merc 2010 E Class W212 2.1 CDI. 2nd Merc 2014 E Class W212 220 CDI
with the mileage your doing a regen should be no problem, my 14 plate does the regen in 10mins and always has.
Not nesserarily...its not only the time it takes to complete a regen, its also the conditions that needs to be met by the system before it will even attempt a regen. They're a bit unpredictable. You could drive 100 miles, but it might only start to regen at the 95th mile, and then fail to complete as the remaining 5 miles is not enough.
 

bladecrazy

Senior Member
Joined
Jun 2, 2020
Messages
447
Reaction score
390
Location
bolton
Your Mercedes
tesla model 3 performance /honda cd175/w123 300d gertrude.
I know they have to be up to temp and enough diesel ect, can only go off my own experience with my e350, regens happen every 3/400 miles and duration is around 10 minutes, this is over a 3year 7month period . i believe the ops car being the smaller engine it should regenerate within 20 miles if conditions are being met, i would reject the car.
 

malcolm E53 AMG

Senior Member
Joined
Aug 21, 2005
Messages
6,993
Reaction score
4,597
I mainly use shell then BP or Texaco (mine strangely likes the texaco pump)
I used the local BP station for years with the S210 320cdi and the car ran very well but always needed an Italian tune up every month to shift the soot that accumulated in exhaust system, done when there was no traffic behind as I’m considerate. The filling station then changed to Esso and low and behold no need for an Italian tune-up the car running much cleaner - amazing the difference even in premium fuels.
 

richlumb

Senior Member
Joined
Jun 5, 2020
Messages
510
Reaction score
504
Your Mercedes
GLC 350d
I used the local BP station for years with the S210 320cdi and the car ran very well but always needed an Italian tune up every month to shift the soot that accumulated in exhaust system, done when there was no traffic behind as I’m considerate. The filling station then changed to Esso and low and behold no need for an Italian tune-up the car running much cleaner - amazing the difference even in premium fuels.
Must admit the best all found is the shell for me and with the bonus rewards you get on the shell card it makes it as affordable as supermarkets,
 

Tony Dyson

Senior Member
Joined
Aug 26, 2018
Messages
4,038
Reaction score
2,585
Location
God's Country
Your Mercedes
2014 C 220 CDI W204 OM 651
Must admit the best all found is the shell for me and with the bonus rewards you get on the shell card it makes it as affordable as supermarkets,
Is that Shell standard diesel or their V Power premium?
 

Stop looking for the Best Garage!! We are here and have the best advanced solutions for you, at Competitive prices. Put us to test with any issue you may have.
Top Bottom