Problem with 2009 906 633 313CDI with OM646 2 Stage Turbo Engine - Mercedes-Benz Forum
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 19 (permalink) Old 01-11-2018, 09:49 AM Thread Starter
Moderator
 
Dave2302's Avatar
 
Date registered: Nov 2013
Vehicle: V220 Ambiente S500 W220 SLK320 R170 C200 CDI W203 Peugeot Expert Van
Location: NW Scotland Near Eilean Donan Castle
Posts: 5,175
Mentioned: 72 Post(s)
Quoted: 709 Post(s)
Lifetime Premium Member
(Thread Starter)
Problem with 2009 906 633 313CDI with OM646 2 Stage Turbo Engine

Hi Guys,

2009 906 633 313CDI with OM646 2 Stage Turbo Engine

Initially this Sprinter had bad starting, lots of cranking needed, the guy kept driving it with EML on, it gradually started losing power until very sluggish then I got it to fix after others had given up

I use MB Star, SDS, (DAS on this model)

Initially it had MAF, EGT Sensor, O2 Sensor and EGR Codes.

I started "round 1 (ding ding)" by replacing MAF, EGT and 02 Sensors, also an Air Filter, all Genuine MB Parts. I did the teach in process for MAF and Air Filter.

It would not allow me to do a DPF Regen at this stage due to constantly flagging EGR code, 2355-002 EGR Rate too high, which I had on "Round 1" so I replaced EGR Motor / Valve Assy, again Genuine MB as "Round 2".
I cleared the Codes then got it to Regen DPF successfully, after which it drove much better power wise.

It now gave the "Air Flow Offset Drift" Code so onto "Round 3"

So far this Van has had a new quality Battery, a new MAF, new EGR, new Lambda, and new EGT Sensor, also new Air Filter just in case...............

The DPF Regen made it pull a lot better but only for about 30 miles, then I cleared codes that had come back, (Air Flow Offset Drift and EGR rate too high), and I did another Regen, drove better again after that. See * below.

It is also still needing a lot of Cranking to fire up, worse when it's part warmed up, despite Injectors passing a Leak off test, they were replaced by another reputable Diesel Specialist Garage last year, and were also coded correctly.

It has decent Rail Pressure when Cranking from Cold, gets up to ~265 bar within a couple or 3 seconds but doesn't actually start firing for at least 15 - 20 Seconds, then stops firing, switch off, re Glow, crank again and it's firing within a few seconds and gradually fires up and starts after about 10 - 15 seconds.

Very recently it has also had a Fuel Quantity Valve and a Fuel Temp Sensor in the Main Pump, which was also checked for the "loose bolts syndrome", all MB Parts and all to no avail..............

It is still hard to start, and a bit down on Power, worse when codes come back and it goes into in limp , actually right now, "fecked if I know"

I dropped the Downpipe at the Turbo today, it was still a cow to start, I am currently comparing Air Flow etc Data from Exhaust attached on / Exhaust Off at Turbo Joint.

EGR, Throttle Valve, Both Turbo Actators, Pre Glow and EGR, Throttle Butterfly etc all pass DAS Actuation Tests.

Only Data that is reading bad is Air Flow on Idle, it is at ~510 mg/Hub and DAS is saying it should be around 380 mg/Hub, plus DAS says on Idle EGR should be around 20% but Actual Value is 6%, same since I replaced the EGR, should I be stripping down Inlet and EGR Pipes and looking for a blockage, with EGR Motor and Valve out of the End of the Intake it didn't look Coked Up ?????????? that's why I changed the EGR Motor and Valve, to no avail ...................

It's got me foxed ATM

Going to leak test Pipework etc after lunch

I've googled etc etc.

"Offset Drift On Idle Code", the Van in Limp Mode, a German guy on U Tube rectified a leak on Boost Joint and cured it, hence me buying the Leak Tester Kit

Anyone got any Ideas ???????

Lunch getting cold, TTFN ...........

OK, back to it after Lunch ............

All Data with Exhaust back on still remains very similar, all the same stuff passes, the only anomalies are Air Flow and EGR rate, same as with Exhaust Off

*DPF Ash and Soot levels low and still well within spec, I suspect it is the recurrence of Fault codes causing lack of power not an Exhaust / DPF Blockage, because obviously I have to clear the codes before it will do a Re Gen, so then I drive it, and it pulls well until the codes come back

So we know Air Flow reading is high mg/Hub and EGR reading is low % but why

I have leak tested from Turbo to Throttle Butterfly, no perceptible Boost leakage, took it up to 20psi still good

I reckon I'm gonna have to pull all the Intake Manifold off it tomorrow to see if there is any leakage / cracks in plastic etc

What do you guys think ???

TIA,

Cheers Dave

pic new Boost Leak Tester in action :-
Attached Thumbnails
Click image for larger version

Name:	SAM_0683.jpg
Views:	609
Size:	65.1 KB
ID:	2350842  

Last edited by Dave2302; 01-11-2018 at 09:53 AM.
Dave2302 is offline  
Sponsored Links
Advertisement
 
post #2 of 19 (permalink) Old 01-17-2018, 07:59 AM Thread Starter
Moderator
 
Dave2302's Avatar
 
Date registered: Nov 2013
Vehicle: V220 Ambiente S500 W220 SLK320 R170 C200 CDI W203 Peugeot Expert Van
Location: NW Scotland Near Eilean Donan Castle
Posts: 5,175
Mentioned: 72 Post(s)
Quoted: 709 Post(s)
Lifetime Premium Member
(Thread Starter)
Hi Guys,

As this is all about a Sprinter 906 now, I'm bringing it across to here, although no one here has replied yet, someone might see something in my next few posts and be able to help

I've done a bit more since above post /\ /\ /\ ............... found out more of what is not the problem

Those Turbo Actuators, there are 2, Wastegate Actuator, and Boost Control Actuator.......... They are all connected up correctly and working fine, passing Actuation Tests, also tried manually holding them in opposite direction to check the effect that had on the Airflow ................

No dice

Also, today, when idling, bobobobobobob sound not there Then it came briefly, then it went, then it came, etc etc

So I started doing the EGR Test open / close routine, each time I did it, the intermittent bobobobobobob returned, but stopped after a few cycles ..............
I then wondered if the ECU is trying to calibrate itself to where the EGR is, but there is no procedure I can find in DAS, and once again, because I can't get any info on this (2 Stage Turbo) Engine, I'm just guessing.
My very helpful and knowledgeable mate in MB even admits him and his colleagues don't really understand them

EGR is reading 6% on Idle before test, then when opened EGR reads 75% Air Flow drops as it should, to around 190 mg/Hub, close the EGR and it goes to 10% air flow is now less, but still not down to spec, sadly I can't get the EGR to vary on DAS Test, cos I reckon that if I could get it to sit at 20% then the Airflow would be right on the money.

So what am I sayin' but just maybe this is EGR Related, but it still doesn't make sense, if it were blocked, surely I wouldn't be getting the 75% figure when open ????? Unless these % figures are measured from the EGR Positioner Motor, and not the Air Flow ????? Perhaps there is a wiring issue, but no related faults, or perhaps the CDI ECU is bad, if but maybe

Mind, should it actually read more when open ????? Who knows ?????

suppose I'm going to have to put my C Class on DAS and log the Data on that, hopefully should be similar, it's a OM646, but Single VGT * see next post

If you got any suggestions at this stage I'd be grateful, btw I've ordered a long USB Endoscope today.

Part of the problem here is lack of access to the MB Strategy Docs for CDI4 ECU, cos I simply don't know exactly what it should be doing and when it should be doing it

Cheers for now,

Dave
Dave2302 is offline  
post #3 of 19 (permalink) Old 01-17-2018, 08:40 AM Thread Starter
Moderator
 
Dave2302's Avatar
 
Date registered: Nov 2013
Vehicle: V220 Ambiente S500 W220 SLK320 R170 C200 CDI W203 Peugeot Expert Van
Location: NW Scotland Near Eilean Donan Castle
Posts: 5,175
Mentioned: 72 Post(s)
Quoted: 709 Post(s)
Lifetime Premium Member
(Thread Starter)
To add to the confusion ..........

Hi again Guys,

@Deplore @pinkster @mrboca @Kajtek1 and anyone else who hopefully knows more than I do

In an ideal world I'd have access to another Sprinter, Identical to this one to read and compare Data, swap Parts etc, but sadly no one around here has one

So waiting on parts for other jobs, today I put my OM646 C Class on the SDS and looked at and wrote down a ton of Data to compare with what I'm getting from that Sprinter.

Now, I know my C Class is a single VGT Turbo, and it is actually CDI3 _UP management and not the same as the 2 Stage Turbo CDI4 managed Sprinter, but I'd reckon that a lot of the Data should be almost the same for comparison purposes

First up, the C Class has not been on SDS for a while now, done around 3000 miles since last worked on, and has no Fault Lights, and drives perfectly, nothing wrong with Engine etc whatsoever, see first photo below

Here's what I found...............

The Airflow highlighting and EGR highlighting appear to be some kind of anomaly in SDS, as my Car is doing exactly the same thing running on Idle at circa 500 mg/Hub airflow, and also EGR at 5%, so I'm now thinking that is all a "Red Herring"

SDS shows the Cars Airflow of 500 ish bang on in the middle within the green sector when doing the HFM-SFI Airflow Test, yet highlights and says it is wrong on the EGR Menu Figures, exactly the same as the Sprinter, one test says bad Data, one doesn't

Soooooo I have absolutely no idea why this Sprinter keeps putting up the EGR Flow and Air Flow Drift Codes, and going into limp, the Car has roughly the same Data Values as the Sprinter all across the board, and Car does not go into Limp and does not put up Codes, Sprinter does :confused

The only thing I noticed with the Car is that before Cranking the Engine the Fuel Rail Pressure is at 4Bar, and rises to 265 instantly when cranking and starting, the Van is at Zero before Cranking and takes 2 to 3 seconds to build up Pressure. When switching off the Car the Rail Pressure bleeds off slowly over a guesstimate of 30 seconds or more, the Sprinter Rail Pressure disappears much quicker, guesstimate around 5 - 10 seconds or less.................

Could well be the cause of the Starting issue with Sprinter, although it still needs a good 20 seconds after rail is up to 260 Bar before it fires up ???? I doubt it will have any bearing on the 2 Air Flow and EGR Codes though !!
Once the Sprinter is running it's Rail Pressures are pretty well the same as the Car

So, stumped once again, 2 steps forward and one backward with this one

Any ideas, this could be the first vehicle in my entire life that has been to me and remained unfixed ????

I'm rapidly getting sick of the sight of it, it is only my un-beaten record that is keeping me going on this one

However, apart from about 4 hrs labour since January 8th this year, the owner is all paid up to date on previous Parts and Labour, so I'm really seriously considering giving up on it

The only thing keeping me going on it, apart from my ego / pride lol, is he's such a nice guy, and he has had problems with this Van ever since he bought it last year, he was sold a "Pup" and has spent 1000's on it since then at various Garages

Please someone must have a suggestion, something I've overlooked, tested wrong etc ???????????

Cheers Dave

Please remember, these pix are Data from the Car which is running fine with no codes etc, not the Sprinter, but Sprinter is showing almost identical Boost, EGR, Airflow, Temps etc etc :-
Attached Thumbnails
Click image for larger version

Name:	SAM_0690.jpg
Views:	173
Size:	33.3 KB
ID:	2354585   Click image for larger version

Name:	SAM_0692.jpg
Views:	293
Size:	44.0 KB
ID:	2354593   Click image for larger version

Name:	SAM_0688.jpg
Views:	185
Size:	45.8 KB
ID:	2354601   Click image for larger version

Name:	SAM_0691.jpg
Views:	259
Size:	53.6 KB
ID:	2354609  

Last edited by Dave2302; 01-17-2018 at 08:53 AM.
Dave2302 is offline  
Sponsored Links
Advertisement
 
post #4 of 19 (permalink) Old 01-17-2018, 09:20 AM
Outstanding Contributor
SDS Guru
 
Deplore's Avatar
 
Date registered: Apr 2014
Vehicle: 1998 MB E300TD, 1997 MB E320
Location: LA, CA
Posts: 3,155
Mentioned: 124 Post(s)
Quoted: 762 Post(s)
So it appears that we have two separate problems, or maybe just one....but one thing that jumps out at me is the residential fuel pressure.

If I understand the CDI fuel rail correctly (which is to say, not at all), it goes something like this:

gas tank (ok, diesel tank, but doesn't sound right) -> low pressure fuel pump (lpfp) -> sensors (fuel temperature/pressure/quantity sensor?) -> high pressure fuel pump (hpfp) -> sensors (pressure sensor, maybe? The few CDI I've seen had a sort of variable pressure regulator in the form of the fuel quantity/pressure sensor, which would bleed the excess back to the gas tank?) -> injectors

So somewhere along that is not holding up the residential pressure when required, leading to hard start. So my question is, since we never got the OM646 here in the US, which component in your car acts as a check valve and fuel pressure regulator?

I mean, there's the fact that your car has 4 bar residential pressure, and thats with it off (presumably for hours). I know in gasser older mercedes had a sort of a check valve built into the fuel pump that would hold the pressure at 1 psi or very close to it, so the car would start nearly instantly when you would crank it.
Dave2302 likes this.

--1998 MB E300TD 291k
--1997 MB E36 Frankenstein'd AMG 199k
--2011 Suzuki DL650 58k
--1997 MB E320 161k. SOLD...loved that stupid car.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

--1997 MB C36 AMG 273k -- stripped and junked
Deplore is offline  
post #5 of 19 (permalink) Old 01-17-2018, 10:04 AM Thread Starter
Moderator
 
Dave2302's Avatar
 
Date registered: Nov 2013
Vehicle: V220 Ambiente S500 W220 SLK320 R170 C200 CDI W203 Peugeot Expert Van
Location: NW Scotland Near Eilean Donan Castle
Posts: 5,175
Mentioned: 72 Post(s)
Quoted: 709 Post(s)
Lifetime Premium Member
(Thread Starter)
Hi,

Thanks for looking at this, much appreciated

I too think that the Hard Starting is separate from the Codes / Limp Problem

Rail Pressure Regulator, governs / holds in the pressure.

Unlike earlier engines, for this one you can't just buy the Regulator, I can only buy a Rail from MB, very expensive !!
Trouble is, there is a few other things that can cause hard starting / fuel pressure bleed off..........
Injector(s) leaking back...........
These were all replaced by a good Diesel Guy last year, and I did Spill Off Leakage Test, and whilst I don't have any specific "ml per 10 seconds" etc figures, they were all even, except no2, and that didn't look to be leaking off much more than the other 3, and certainly they were comparable to the 2 CDI Vito's with the same type, (solenoid), Injectors that I have Spill tested, both Vitos start fine

Quantity Control Valve is what does Fuelling when starting, (cranking), and can cause hard start, I have changed that

There is also a reported issue that the Bolts holding the Pump together can come loose and cause hard start too, but I have had the Pump off and checked that, no dice all good and tight

So ideally I'd like to fix them Codes first, I cannot think how Rail Pressure could possibly affect them, as it only flags them well after it has started, at which point the pressures are the same as the Car !!

After fixing the Codes, then, if it still starts hard, maybe I'll fit a new MB Rail with Regulator ~ 900.00,

I don't really wanna fit one unless I'm absolutely certain

I was going to try the C Class Rail, but it is different p/n grrrrr !!

This is my problem, no one is sharing exact data specs, and I cant find a Sprinter locally that I can borrow to swap bits from

The guys I know in MB who do work on Sprinters, and are on the whole very helpful to me just shake their heads and wish me good luck lol.

Cheers Dave
Dave2302 is offline  
post #6 of 19 (permalink) Old 01-17-2018, 12:02 PM
BenzWorld Elite
 
Kajtek1's Avatar
 
Date registered: Dec 2005
Vehicle: E320/E250 Bluetec Ford F350 6.7l
Location: V E G A S
Posts: 35,387
Mentioned: 30 Post(s)
Quoted: 1976 Post(s)
Strange why you can't buy rail pressure regulator?
Those regulators do have some failures for years and I read the reports where in some instanced whacking them with butt of big screwdriver made them working better.
Still there is more that can leak beside regulator
I see the topic landed in Sprinter section, but coming back to technology, my W212 diesel has ECO start. Did not investigate the system very far, but it is using rail residual pressure to fire up the engine.
I can sit at red light for 2 minutes and the engine restarts in nanosecond
Faster than it takes me to move my foot from brake to gas pedal
So the system should keep thousands of psi for at least long minutes.
Dave2302 likes this.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Kajtek1 is offline  
post #7 of 19 (permalink) Old 01-17-2018, 02:37 PM
Outstanding Contributor
 
pinkster's Avatar
 
Date registered: Jul 2013
Vehicle: 2002 S430
Location: Brisbane, Australia
Posts: 1,899
Mentioned: 84 Post(s)
Quoted: 381 Post(s)
Dave, the vans throws the code after driving. So hook up DAS and go for a drive while reading the live data. You will want to be reading the fuel pressures and egr flow rate etc and see what is happening when it spits the dummy.

This may help with the trouble. Could be that it is losing pressure intermittently. Pete's S-class was throwing a misfire code for just 1 cylinder and after checking everything it turned out to be a fuel pump issue, was losing just enough pressure to starve the last cylinder on the rail.
Dave2302 likes this.

Dean

GMT +10

2002 W220 S430
2003 Toyota Rav4
2017 Yamaha Stryker
pinkster is offline  
post #8 of 19 (permalink) Old 01-18-2018, 02:12 AM Thread Starter
Moderator
 
Dave2302's Avatar
 
Date registered: Nov 2013
Vehicle: V220 Ambiente S500 W220 SLK320 R170 C200 CDI W203 Peugeot Expert Van
Location: NW Scotland Near Eilean Donan Castle
Posts: 5,175
Mentioned: 72 Post(s)
Quoted: 709 Post(s)
Lifetime Premium Member
(Thread Starter)
Hi Dean,

Thanks for that, I will have to find someone else to drive it whilst doing that, it does also put the Codes up whilst standing still doing SDS Tests, just takes a while, and also the EML doesn't come on to let me know exactly when it spat it's dummy, it takes 2 or 3 drive cycles, (read stop and restart engine) before light comes on, but the code is flagged without light coming on, when Testing & Data watching I keep checking it for codes, that's how I found that out
@Kajtek1

All the good,( read no codes or starting problems), OM646 CDI's and other CDI's I have looked at Data on, the Fuel Rail Pressure drops away slowly over about 10 - 30 seconds as soon as you switch Engine Off, some to zero, some to 2 - 4 Bar............

Thing is they build almost instantly when Cranking, faster than SDS can monitor, and those Engines when hot all start instantly, and when Cold under 2 Seconds.............

This Sprinter takes 2-3 seconds to hit minimum pressure cranking, (~250 Bar) but then if it is purely a pressure issue it should start, it doesn't, I have to hang on the Starter for a further 10-18 seconds before it starts firing but not running, and when it gets to about 25 seconds I stop cranking, re glow, crank again, it is firing and gradually starts over 5-10 seconds.

Note that I'm describing it Firing and it Starting as 2 separate things

Also this Sprinter, the pressure drops off faster than the others, yes there is a pressure problem, but I really don't think it is related to the 2 Codes. !! Tell me if you think I'm wrong here !!

The codes don't come up until it has been driven for a while, or been running for a while whilst testing stuff

Yes I can buy a Regulator for the older CDI's on it's own, even get the Sealing Rings, but these newer ones you cannot, it has to be changed as a complete Rail with Regulator, due to various reasons...........

Mostly how it is manufactured, if you remove the Regulator and refit it will not seat properly, someting to do with a metal Knife Edge sealing it to Rail, which digs into the Aluminium Rail, that is how it was explained to me, and EPC only lists complete Rail
Yes I can buy the Rail Pressure Sensor separate, but that reads fine when monitoring and puts up no codes

Still

I expect I'll spend a bit more time with it next week now, more Data Logging like Dean said, but right now there is other work to do

Thanks for all the comments and observations, keep 'em coming.

Edit, one final thing I'm thinking of right now, waaaay back, I did the SDS Compression Test, which basically measures Cranking RPM against Crank / Cam Position, and gives a graph of Cranking RPM for each cylinder, 3 cylinders were fine, one was very very few RPM out of the "Green OK sector", now I've had 2 CDI's that have holed a Piston, crank a bit longer, but still they start much quicker than this one ..........but ..........
I'm just thinking............. .......... If say there is an Intake or Exhaust Valve blowing slightly, do you think it could cause these Codes as well as bad starting ??

Bearing in mind it Idles smoothly and Cylinder Balance is OK, is it worth the potential hassles of trying to get the Glow Plugs out and doing a Compression Test with a Gauge ?? What think you ??????

Cheers for now, Dave

Last edited by Dave2302; 01-18-2018 at 02:30 AM.
Dave2302 is offline  
post #9 of 19 (permalink) Old 01-18-2018, 08:50 AM
Outstanding Contributor
SDS Guru
 
Deplore's Avatar
 
Date registered: Apr 2014
Vehicle: 1998 MB E300TD, 1997 MB E320
Location: LA, CA
Posts: 3,155
Mentioned: 124 Post(s)
Quoted: 762 Post(s)
Yes, sounds like you're on the right track here, the lengthy cranking before starting is certainly odd, points to incomplete fuel/air mixture.... Which is even more odd, since diesels have extremely wide auto ignition range (AFR is wider) than a comparable gasser.
Dave2302 likes this.

--1998 MB E300TD 291k
--1997 MB E36 Frankenstein'd AMG 199k
--2011 Suzuki DL650 58k
--1997 MB E320 161k. SOLD...loved that stupid car.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

--1997 MB C36 AMG 273k -- stripped and junked
Deplore is offline  
post #10 of 19 (permalink) Old 01-18-2018, 10:06 AM Thread Starter
Moderator
 
Dave2302's Avatar
 
Date registered: Nov 2013
Vehicle: V220 Ambiente S500 W220 SLK320 R170 C200 CDI W203 Peugeot Expert Van
Location: NW Scotland Near Eilean Donan Castle
Posts: 5,175
Mentioned: 72 Post(s)
Quoted: 709 Post(s)
Lifetime Premium Member
(Thread Starter)
Hi,

Well I've ordered a MB CDI Adaptor for my Diesel Compression Tester Kit today, I've never had to use it on a CDI before, normally if they pass the SDS Cranking test Compressions are OK...............
But another tool addition to add to my arsenal

When it arrives, will get some figures

Meanwhile, if anyone has any suggestions, observations, or just plain want's to say "you silly old fart, you have not thought of 'xyz' " please feel free to chime in, I'm all ears on this one

Thanks for "listening",

Cheers Dave
Dave2302 is offline  
Sponsored Links
Advertisement
 
Reply

  Mercedes-Benz Forum > Mercedes-Benz Vans/Trucks/SUV/Others > W901-906 Sprinter

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Mercedes-Benz Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 

Title goes here

close
video goes here
description goes here. Read Full Story
For the best viewing experience please update your browser to Google Chrome