E350 black exhaust smoke on hard acceleration

[Roger57]

This topic has been discussed before on this forum, I know. Black smoke on hard acceleration. Some folks say it is quite normal, some dont. I do know that there are certain things which can contribute to excessive smoke, one of those being that the car has been 'chipped' (I know this because I have previously had an ML which I had chipped). I believe that my currrent 2011 E350 (W212) has been chipped by a previous owner.

The concern is that the problem seems to be getting worse. Although it could be just my imagination......

Having read other posts on this forum I believe that there may be a couple of other popular potential causes for this. One being the DPF and the other being the EGR valve becoming clogged with soot. I have read that the EGR valve can be removed and cleaned out. So, two questions....

Can the EGR actually be cleaned out? And..

Where is the EGR valve on this engine? Its a 3.0 V6 diesel. W212. 2011.

I also understand that the DPF should 'regenerate' automatically. Presumably this process is regulated by the ECU through inputs from various sensors. I have recently obtained an iCarsoft CR Pro scanner which I believe can be used to initiate the regeneration process manually, although I have not yet been able to get it to work (a result of operator incompetence, probably). I have also read that this process does not work on all vehicles, so if anyone has done this with the CR Pro on this engine I would appreciate some guidance please.

So. EGR and DPF...over to you....can you help?

 

[Roger57]

This topic has been discussed before on this forum, I know. Black smoke on hard acceleration. Some folks say it is quite normal, some dont. I do know that there are certain things which can contribute to excessive smoke, one of those being that the car has been 'chipped' (I know this because I have previously had an ML which I had chipped). I believe that my currrent 2011 E350 (W212) has been chipped by a previous owner.

The concern is that the problem seems to be getting worse. Although it could be just my imagination......

Having read other posts on this forum I believe that there may be a couple of other popular potential causes for this. One being the DPF and the other being the EGR valve becoming clogged with soot. I have read that the EGR valve can be removed and cleaned out. So, two questions....

Can the EGR actually be cleaned out? And..

Where is the EGR valve on this engine? Its a 3.0 V6 diesel. W212. 2011.

I also understand that the DPF should 'regenerate' automatically. Presumably this process is regulated by the ECU through inputs from various sensors. I have recently obtained an iCarsoft CR Pro scanner which I believe can be used to initiate the regeneration process manually, although I have not yet been able to get it to work (a result of operator incompetence, probably). I have also read that this process does not work on all vehicles, so if anyone has done this with the CR Pro on this engine I would appreciate some guidance please.

So. EGR and DPF...over to you....can you help?

If anyone has any useful information I would appreciiate it, thanks.

 

[Bellow]

As far as I know, cleaning the EGR is just taking it apart and cleaning all the accumulated carbon from the valve and associated pipework.
As for the DPF - you'll have to wait until one of the guys accustomed to re-gens answers.

 

[Roger57]

Bellow,
Thanks for your reply.

Are you familiar with this particular engine?

Do you know where I will find the EGR?

 

[TeddyRuxpin]

HI mate,

A healthy E350 (with a functioning EGR and DPF) shouldn't really smoke under any circumstances - even with a remap.

The only instance it will smoke is if there's some kind of problem - but it will definitely smoke under acceleration if somebody has gutted the DPF. Is this car new to you - are you sure that it has one?

(Even if it's there, the inside might have been gutted)

FYI the EGR is at the back of the engine (as you're facing it), just to the right of the turbo. But I don't think it's that.

You should grab a CarSoft MB2.0 and scan the car for errors as a first port of call. The car should do a DPF regen every 200-300 miles, and there are a few telltale signs that it's doing a regen:

1) Car will idle at ~800rpm instead of ~550rpm (a bit like in the winter when the car is cold/warming up)
2) Car will hold onto gears for longer and change gears at higher rpm
3) There will be a lot of heat generated when you stop (i.e. when you open the door you'll feel it under the car)
4) There will be a burning plastic/rubber smell when you stop and get out of the car if it's mid-regen.
5) The exhaust tone will be quite loud/droney/boomy/kind of awesome during a regen (as opposed to the usual silence)

Cheers,

Ed

 

[Bellow]

Bellow,
Thanks for your reply.

You're welcome. Where is everyone else?

Are you familiar with this particular engine?

No, I'm not. But plenty here must be - where are they?

Do you know where I will find the EGR?

I'd have to trace the pipe work from the two manifolds to make sense of it. But others here have done this so will know.

Strange isn't it? Here you are a member for 7 years asking for help with cleaning your EGR ie, proper maintenance and are being ignored. Someone joins the forum and posts asking how to delete their EGR and forum members are all over him like a rash offering advice.

 

[Bellow]

HI mate,

A healthy E350 (with a functioning EGR and DPF) shouldn't really smoke under any circumstances - even with a remap.

The only instance it will smoke is if there's some kind of problem - but it will definitely smoke under acceleration if somebody has gutted the DPF. Is this car new to you - are you sure that it has one?

(Even if it's there, the inside might have been gutted)

Could a DPF delete in the ECU be the cause of this (below)?

I also understand that the DPF should 'regenerate' automatically. Presumably this process is regulated by the ECU through inputs from various sensors. I have recently obtained an iCarsoft CR Pro scanner which I believe can be used to initiate the regeneration process manually, although I have not yet been able to get it to work (a result of operator incompetence, probably). I have also read that this process does not work on all vehicles, so if anyone has done this with the CR Pro on this engine I would appreciate some guidance please.

 

[TeddyRuxpin]

If a tuning company guts the DPF they will definitely adjust the map to take 'advantage' of that (I disapprove strongly), but it's not possible to simply code out the DPF or regen. You can 'delete' the EGR valve usage via software, often done by some remappers during a remap (e.g. GAD), but that won't make the car smoke - from my understanding, the extra unburnt fuel/soot that the EGR would have put back into the engine is a small amount, and will be 'caught' by the DPF. Sorry if that's not what you meant?

FWIW my iCarSoft MB2.0 doesn't show correct values for DPF data for my 2009 E350 (231bhp) so it's pretty useless in that regard - but it does for my dad's E350 (265bhp). I actually thought I had a DPF issue from the crazy sensor readings and even took it into an indie with a proper STAR scanner to check the DPF due to this, but it turns out the unit (with the latest firmware at the time) simply didn't work with my car. My DPF was fine/perfect.

Edit: Another thing to note is that if the car has a fault it will often delay/not do a regen, which can cause a build up.

But as you have a scanner, if you scan the engine, do you get any errors?

 

[TeddyRuxpin]

By the way, I initially read your post on my phone and some of it didn't fully process in my brain. I'm on my computer now and have re-read your message and can see that it's had a remap by the previous owner. Apologies.

The long and short of it is: Even with a remap, it shouldn't smoke under heavy acceleration. I might be wrong but, I think the previous owner probably gutted the DPF during the remap to get an extra few horse power, thus causing the smoke on acceleration.

 

[Bellow]

If a tuning company guts the DPF they will definitely adjust the map to take 'advantage' of that (I disapprove strongly), but it's not possible to simply code out the DPF or regen.

Presumably, the complete absence of any pressure differential across a gutted DPF means the ECU will never see the need to perform a re-gen.

You can 'delete' the EGR valve usage via software, often done by some remappers during a remap (e.g. GAD),

Part of that will be control of the 'throttle' valve which influences the balance of fresh air vs recirculated gas ie, with deletion of EGR the bias will be towards permitting plenty of fresh air to be admitted to the engine without restriction (and all but completely closing the engine off to EGR admission). But, with EGR still enabled but blocked (with debris) is it possible the throttle valve doesn't permit enough fresh air to pass and with no EGR the engine is starved of air - hence black smoke?
Pure supposition on my part re the functioning and sizing of the 'throttle' valve.

but that won't make the car smoke - from my understanding, the extra unburnt fuel/soot that the EGR would have put back into the engine is a small amount, and will be 'caught' by the DPF. Sorry if that's not what you meant?

If any unburnt fuel/soot is there at all. Mainly, EGR is exhaust gas (with different to air thermodynamic properties) and uncombusted air (oxygen) present due to the lean burn combustion principle the diesel operates on.

 

[TeddyRuxpin]

I don't think any remapper would keep EGR valve use and gut the DPF, they'll do both at the same time (and even advertise as such). So, the engine gets lovely fresh air 100% of the time and all the unburnt fuel goes out the back of the engine. But then there's no DPF out the back to catch all the soot/unburnt fuel, and so all that crap goes out the tail pipe on heavy throttle.

Apologies to the OP if it's a completely different issue, not trying to scare you!

If the car is working just fine and has a DPF and the EGR is blocked, they usually block closed and the amount of extra soot that is created really wouldn't be enough to create 'plumes' of black smoke. As I said, lots of reapers will software-delete the EGR and keep the DPF and there shouldn't be smoke.

The EGR valve supposedly used on hard acceleration only on light throttle (i.e. it closes when you floor it)), but of course if there's a lot of soot on the DPF (assuming it's there) it could create a bit more 'smoke' out the exhaust, but nothing that should be hugely noticeable.

 

[TeddyRuxpin]

The EGR valve supposedly used on hard acceleration only on light throttle (i.e. it closes when you floor it)), but of course if there's a lot of soot on the DPF (assuming it's there) it could create a bit more 'smoke' out the exhaust, but nothing that should be hugely noticeable.

This should read: The EGR valve is apparently not used (remains closed) on hard acceleration, only on light throttle. It closes when you floor it.

 

[Bellow]

This should read: The EGR valve is apparently not used (remains closed) on hard acceleration, only on light throttle. It closes when you floor it.

Is it not the other way around? EGR deployed under high power as that is when NOx forms and the purpose of EGR is to reduce NOx?

 

[TeddyRuxpin]

I understand your thinking, but no: The basics of EGRs - what they do, how they work, how to troubleshoot | Delphi Auto Parts

The EGR valve has two primary settings: open and closed, although the position can vary anywhere in between. The EGR valve is closed when the engine is starting up. During idle and at low speeds, only a small amount of power is required, and therefore only a small amount of oxygen, so the valve gradually opens – it can be up to 90% open at idle. However as more torque and power is required, for example during full acceleration, the EGR valve closes to ensure as much oxygen enters the cylinder.

 

[markjay]

STAR or iCarsoft will tell you the soot contents in the DPF.

Black smoke can be (among other things) the result of over-fuelling, than can be (among other things) the result of injector leak, or of engine oil getting into the combustion chamber, though the later will produce smoke with a blueish hue.

Before considering whether the engine was remapped or not, the DPF gutted and the EGR disabled, I would start with the basics:

A bottle of Diesel fuel system cleaner (Redex/Forte/Millers/BG44 etc) mixed with the existing fuel.

Followed by a couple of tankfulls of Shell V-Power Diesel (or other premium fuel).

And check the level of the engine oil - it should be well below the Max mark when the oil is hot.

 

[Bellow]

I understand your thinking, but no: The basics of EGRs - what they do, how they work, how to troubleshoot | Delphi Auto Parts

I'm not entirely convinced by the linked article but as I'm not completely conversant with OEM ECU programming I'm not for arguing.

Back on topic! - I guess it won't do harm for the OP to give his EGR system a clean up. If it is operational it would benefit and if it has been mapped out maybe the EGR valve showing that it has been stuck in the same position for a long time may point to EGR having been mapped out.

 

[Roger57]

Wow. Lots of stuff there, eh...

First of all, I have noticed that intermittent burning smell before. And yes, occcasionally the exhaust does sound different. And I have also noticed occasional brief changes in idle speed. So it sounds like it is behaving as it should. Doesnt it?

As far as whether the car has a DPF....yes, I believe it does. It shows up on my iCarsoft (mine is a CR Pro) and yes, it does tell me the % soot content.
I cannot seem to find a method of initiating manual regeneration with my CR Pro; but then if it is doing what it should, I shouldnt need to, should I. If it isnt broken, I have no wish to fix it.....

I believe that the CR Pro also tells me how long the engine has been run since the last regen?

(I havent had the CR Pro very long so I'm probably not looking properly...)

When I noticed the reading for soot percentage I failed to make a note of what it was. So. Two more questions, sorry...

Presumably a higher soot content in the DPF will contribute to (excessive) black smoke? I might try and keep an eye on the soot levels. That will give me an indication that the regeneration process is active, wouldnt it? And rather nerdy too....

and

One of the contributors here spoke about 'gutting' the DPF. Is it possible to examine it to check? Where might I find it on this car?
Its a 2011 W212 E350 Bluefficiency Estate model.

Many thanks to all of you for your contributions....but I have to admit to some ignorance as far as the extreme technical detail is concerned..!

 

[markjay]

The DPF is under the car sort of halfway along the exhaust pipe, it is sort of spherical in shape and will have a wire coming out of it (though the wire might not be visible from under the car).

You're looking for signs of tempering, e.g. newly welded seams, shiny bits of metal showing that the pipework has been disturbed, etc. These could indicate that the DPF was cut open, gutted-out, then welded back together. But, of course, it may have also been removed altogether!

In either case, a software reconfig would have been carried out to tell the engine ECU that the car no longer has a functioning DPF, or you'd have the EML on the dash light-up. But in this case, your iCarsoft would not have been able to communicate with the DPF sensor.

I don't think that high soot level in itself will cause black smoke. The black smoke may be caused by a regen, but them only when the regen occurs.

 

[Bellow]

Wow. Lots of stuff there, eh...

First of all, I have noticed that intermittent burning smell before. And yes, occcasionally the exhaust does sound different. And I have also noticed occasional brief changes in idle speed. So it sounds like it is behaving as it should. Doesnt it?

By what I've read on this forum, yes.

As far as whether the car has a DPF....yes, I believe it does. It shows up on my iCarsoft (mine is a CR Pro) and yes, it does tell me the % soot content.
I cannot seem to find a method of initiating manual regeneration with my CR Pro; but then if it is doing what it should, I shouldnt need to, should I. If it isnt broken, I have no wish to fix it.....

Yes, again - if it is self re-genning.

Presumably a higher soot content in the DPF will contribute to (excessive) black smoke? I might try and keep an eye on the soot levels. That will give me an indication that the regeneration process is active, wouldnt it? And rather nerdy too....

To my mind, nothing should get past the DPF that is visible - not even invisible particulates.

and

One of the contributors here spoke about 'gutting' the DPF. Is it possible to examine it to check? Where might I find it on this car?
Its a 2011 W212 E350 Bluefficiency Estate model.

As per MJ's comments - and if you do find it, give it a tap with a hammer and listen to hear if it sounds 'hollow'. A functioning DPF must be a pretty solidly packed thing to filter as it should.

When you see smoke - is it on initial acceleration only or does it persist for as long as you have your foot in it?

 

[Roger57]

Ermm....well...need to be a little careful here...

Lets just say that when I give it the boot at 'motorway speed' that is when I notice it. If I keep my foot down it fades off. And it definitely appears to be black, not blue.