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2006 E320 CDI
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From my understanding of the diesel engine description posted above, this is only true for the OM651 engine. This uses piezo operation with 24 digit adjustment code, and replaces the OM 646 solenoid operation with 18 digits.

" I2C coding:

On engine 651 with the new CDI system, the coding has been extended to a 24-digit I2C code. The I2C coding permits even more accurate tuning (injection quantity and injection period) of the individual piezo injectors when new.

If a piezo injector is replaced, the CDI control unit must be supplied with this coding via Star Diagnosis. It must be ensured that the correct I2C codes are entered after replacing the injectors. If the I2C codes are entered incorrectly or not at all, the following problems may arise:

• Smoke formation
• Rough or vibrating engine
• Power loss
• Generation of noises"
Please read the provided MB document carefully - it says:

IMA coding
Following the introduction of the following engines:
engine 648 as of engine end number: 064541
with CDI 3 1600 bar system converted for these engines to IMA coding (Injector Quantity Compensation).
These injectors also show the marking of the magnet group, a 6-digit number-letter combination (see bordering in picture), similar to
the injectors of the CDI 2 system.
 

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2004 CLK 240 Coupe
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Please read the provided MB document carefully - it says:

IMA coding...
Aah...you could well be right here wrt OM 648. But I was only going by what is in the above MB document (Page 41 ref Piezo injectors in engine OM 651)

I can find no reference there to engine OM 648. :confused:
 

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Aah...you could well be right here wrt OM 648. But I was only going by what is in the above MB document (Page 41 ref Piezo injectors in engine OM 651)

I can find no reference there to engine OM 648. :confused:

I just posted that so others may be able to understand the differences between the OM648, and the newer OM651 and to say I'm glad I have the OM648. I removed that link so it doesn't confuse others.
 

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2005 E320 CDI 120k
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225 Posts
Discussion Starter #46
Hi All-
Just wanted to let everyone know I got the injector back in and working properly!! And Thank you to everyone who contributed - I could not have done it without you! Turns out I had taken off the top of the injector and the microscopic ball was not seated properly causing it to not work.

Here's my partial summary from the job:

-Milling the face of the injector did not kill it. Cost $40 from local machine shop.
-Cyl head surface was ok - no need to resurface.
-Made a tool to clean the carbon out of the hold down bolt threads by cutting two grooves in the old injector bolt with a hacksaw. Must have screwed/unscrewed the bolt 25 times to get all the carbon out.
-When you take out the injector, I'd suggest running a hose from the return line to a container. In my case it flooded the cylinder with diesel and I had to crank the engine over to blow it out or might have damaged the engine had I not seen it.
-Goof Off really cleans the black/carbon out well.
-Engine should be hot when removing injectors. The coefficient of thermal expansion for alum (cyl head) is 3x that of steel (injectors) so you are more likely to get the injectors out when they are hot.
-Used the MB injector puller with the 5 lb slide hammer from Harbor Freight. Threads on puller and hammer didn't quite match but it worked well.
-Martin Wainwright has two videos on YouTube about disassembling the CDI injectors if you are so inclined.
 

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2005 E320 CDI
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Hi All-
Just wanted to let everyone know I got the injector back in and working properly!! And Thank you to everyone who contributed - I could not have done it without you! Turns out I had taken off the top of the injector and the microscopic ball was not seated properly causing it to not work.

Here's my partial summary from the job:

-Milling the face of the injector did not kill it. Cost $40 from local machine shop.
-Cyl head surface was ok - no need to resurface.
-Made a tool to clean the carbon out of the hold down bolt threads by cutting two grooves in the old injector bolt with a hacksaw. Must have screwed/unscrewed the bolt 25 times to get all the carbon out.
-When you take out the injector, I'd suggest running a hose from the return line to a container. In my case it flooded the cylinder with diesel and I had to crank the engine over to blow it out or might have damaged the engine had I not seen it.
-Goof Off really cleans the black/carbon out well.
-Engine should be hot when removing injectors. The coefficient of thermal expansion for alum (cyl head) is 3x that of steel (injectors) so you are more likely to get the injectors out when they are hot.
-Used the MB injector puller with the 5 lb slide hammer from Harbor Freight. Threads on puller and hammer didn't quite match but it worked well.
-Martin Wainwright has two videos on YouTube about disassembling the CDI injectors if you are so inclined.



Warren,


Wow! Great work :) Thanks for the job summary and recommendations on what seemed to work well for you as far as removing the black gummy goo. I like the idea for the carbon thread removal. Simple, cheap, and highly effective :thumbsup: I like that you mentioned making a tool for cleaning the carbon from the copper crush waher sealing surface interface down on the head. I personally wouldn't even consider not using some minimally abrasive method to clean the carbon from sealing surfaces. Not cleaning things up properly is just inviting a potential future issue with leaks. On these fairly high combustion pressure, and high injection pressure vehicles we need all the help we can get.

I removed and replaced copper crush washers on my VW TDI injectors and made my own sealing surface cleaning tool for that. It was a 1/4" shaft around 12" long, a steel washer of appropriate size secured to the end, and some very lightly abrasive green scotch pad attached to the washer. I poked some paper towel material down the hole a bit so no foreign material went where it wasn't supposed to be, and used a vacuum with a miniature suction nozzle to remove debris. I also made sure no metal surfaces of my cleaning tool touched the aluminum sealing area and it worked beautifully. I finished it off by polishing it with a lint free cloth attached to my tool and the screw gun and used some carb cleaner to lubricate and remove potential contaminates while doing it. It worked out extremely well. 3 out of 4 of the injectors didn't leak-the fourth was leaking and I simply took it back apart, cleaned the surfcae better the 2nd time, and all has been well for couple years now.

Thanks for pointing out that guys name for the injector info on Youtube. Searching for his stuff led me to this:




I did want to ask you, how much did it cost for the mercedes injector puller piece? I currently have a slide hammer portion, just would need the fork adapter piece when/if it comes time for me to do this :)
 

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2005 E320 CDI 120k
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Discussion Starter #48
MB injector puller was around $120 or so. MB dealer said, however, there were only two left in the country and they aren't going to make them anymore :(.
 

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Discussion Starter #49
FYI, in Josh8loop's video of removing injector "version B", when you unscrew and remove the top of the injector there will be some very tiny almost invisible parts of the injector (very small ball and seat) that you need to get out and reassembly properly.
 

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2005 E-320 CDI Sedan, a W-211
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Thanks Josh

Looks like they are classified into 3 levels of fuel metering characteristics.
I would think that as long as you order exactly the same part with the same
fuel metering characteristics, you should be fine to throw it in and go.
Most likely the coding number modifies an Algorithm and adapts the fuel
injector pulse "on" time to help keep fuel injector fuel contribution even.
Also, IIRC this vehicle features active idle control up to something like 1200 RPM.
If there was too much deviation then it would set a DTC.
"as long as you order exactly the same part with the same fuel metering
characteristics, you should be fine to throw it in and go."

That is exactly what I evidently did and everything is working correctly now for over 28K miles and 15 months.
See my Fuelly entry on January 11, 2012.

How can I find my engine number?

Derrel
 

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2005 E-320 CDI Sedan, a W-211
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Extra Injections for the V6

I'm glad I went with the OM648! There are a few benefits of the newer CDI control scheme, but there are some drawbacks too. Namely that stinking double post injection to regenerate the DPF and keep the Catalytic converter hot.
I bet removing the two post injections and getting rid of the DPF & Catalytic converter would increase engine efficiency
quite a bit. Too bad that's illegal to do :rolleyes:
:)

"Namely that stinking double post injection to regenerate the DPF and keep the Catalytic converter hot."

Isn't that one of the reasons our fuel economy is better? :confused:
The 2007 and later V6 3.0 liter engines should most certainly get better fuel economy
because that engine is not only smaller that the I-6, but the V6 cars have
the 7G transmissions and ten (10) percent taller gearing.

:D

Derrel
 

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:)

"Namely that stinking double post injection to regenerate the DPF and keep the Catalytic converter hot."

Isn't that one of the reasons our fuel economy is better? :confused:
The 2007 and later V6 3.0 liter engines should most certainly get better fuel economy
because that engine is not only smaller that the I-6, but the V6 cars have
the 7G transmissions and ten (10) percent taller gearing.

:D

Derrel
Yup, most likely why they don't get as good of fuel economy. Also they may have more electrical consumption than out versions-not sure just a guess. Like you mention the 7 speeds and the taller gearing and also the super fast piezo multiple injection injectors should give superior MPGs if it weren't for the aftertreatment stuff. Now if we could easily retrofit ours with the piezo injectors and remove restrictive exhaust components we would possibly see increase in fuel economy.
 
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