E220 Diesel: Disabled my EGR today.
This week I went to the dealer and as it turns out there's an original MB coverplate to close the EGR valve! "cuz these engines have also been available without EGR", lol!
Did the project today and what a difference! The engine is much more responsive and runs quieter. I've been driving around in the afternoon, city traffic and stepped on it on the highway upto 160km/h (100mph). The car pulls better and feels smoother, and no EPC warning!!!
Here's a pictorial. I guess it's the same procedure on a 300 Diesel OM606 non-turbo engine it's the same block just with two more cylinders. On turbo's I'm not sure cuz these have a metal inlet header and I think the EGR is routed different...
The parts: (coverplate and two gaskets on each side)

Thick layer of soot buildup inside the throttlehousing:

Soot on the throttle itself:

Throttlehousing cleaned up:

Coverplate installed between EGR-valve and throttlehousing:

Everything still looks OEM:

Soot buildup in engine inlet channels:

Inlet channels (and also header-innards) cleaned:
Last edited by Lancelot; Jan 17, 2009 at 04:12 PM.
Does anybody know what electronics are on these engines that may cause this? I'm willing to do almost whatever it takes to get rid of this ****. It's screwing up my engine really bad!
Does anybody know what electronics are on these engines that may cause this? I'm willing to do almost whatever it takes to get rid of this ****. It's screwing up my engine really bad!

a good excuse to get the engine chiptuned too
can't really afford it, but I may be able to kick up something
Would prob work on the gassers too.
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I see a big reason why it would NOT work on your engine. The linked article is about an earlier OM606 Turbo Diesel engine. This engine still has a mechanical injection pump with some electronic control (like my engine). Yours is a CDI engine, a totally new generation, these have fully electronically controlled direct injection and if I'm not mistaken even a engine-knock-sensor and stuff. You do not want to start snipping wires based on a tale about an older engine. Your wiring is probably totally different to begin with! I would look into the chiptuning thingy, or maybe you can find a 'powerbox'. Those are widely used on TDI/CDI/HDI etc. engines...
Below some pics of a late W210 220CDI Amterdam taxi. The engine looks pristine until they remove the EGR.
- and they say this is better for the environment than NoX output - *cough*


Last edited by Lancelot; Jan 19, 2009 at 10:58 AM.
I would think it would work to emulate an EGR-opening with a voltage drop on the MAF, but what do I know?
I had a plan to create a second inlet parallel with the MAF to open when the EGR is supposed to open. Don't know if this will work...
I would think it would work to emulate an EGR-opening with a voltage drop on the MAF, but what do I know?
I had a plan to create a second inlet parallel with the MAF to open when the EGR is supposed to open. Don't know if this will work...
Anyways after two days of driving around, I keep noticing the following:
Even after a cold start the engine is more responsive. (used to be sloooow until warm)
When driving at a steady city traffic speed (like 50-60km/h) I always noticed a slight rpm variation, this is now gone.
I haven't seen the ABS-ASR-BAS error that's been plaguing me for so long now, the engine fires instantly after preglow. Maybe the alternator is now immediatly suplying the correct Voltage?! I'm sceptical about this, maybe I'll start believing in it after a few weeks without the warning showing.
Last edited by Lancelot; Jan 19, 2009 at 01:09 PM.

The guy who changes the software confirmed to my mechanic that the egr could be mapped away. But he couldn't guarantee that it would really work the way I wanted it to. But at least the car runs better
But there is actually less black smoke I think...
Last edited by Semikolon; Jan 21, 2009 at 12:17 PM.
I would think it would work to emulate an EGR-opening with a voltage drop on the MAF, but what do I know?
I had a plan to create a second inlet parallel with the MAF to open when the EGR is supposed to open. Don't know if this will work...
Start reading here... this works on a non-CDI OM606.962 got it this time - egr bypass 606 turbo
Anyways, my problem is solved, EGR is mapped completely away in the ECU
). I had my intake cleaned about 12-15 000 kms ago, so it didn't require very much to get rid of just enough dirt to make the ride smooth again 
Before the engine was a bit unstable on idle, now it's usually not a sign of unstability, only when I start it cold, there are some rev variations for a few seconds. It now shakes much less than before when stopping the engine, and braking down to a full stop is much smoother
It's simply amazing! I can recommend this to everyone!
The ECU performs the following check to see if EGR is functioning:
Whenever the warm engine is idle for more then 10 seconds, the ECU closes both the throttle- and EGR-valve for 2 seconds. As you can see in my pics above the throttlevalve has a straight edge so some air can always pass. After these two seconds the ECU opens ONLY the EGR and looks for a pressure drop (of only a few milliBARs) on the MAF. Since the MAF is located BEFORE the throttlevalve and the EGR BEHIND the throttlevalve, the suction past the closed throttlevalve should lower slightly when the EGR opens (sucking in exhaust gases now) If on two consecutive trips this test is failed the EPC warning is triggered and the car goes into limp-home-mode.
On non-turbo diesels (my OM604 220D and the OM606 300D) there's no MAF! It looks like a MAF but is actually an inlet-air-temperature sensor. This is why we can get away with closing the EGR on these engines...
Last edited by Lancelot; Feb 2, 2009 at 03:12 PM.
Had that cold start unstability on my 220d-96.
I just disconnected the vacuumtube connected to the EGR "controller".
The engine is now running smothly in all conditions.
(I blocked the vacuum tube with a screw)
Good Luck from Torehol


