EGR Block plate for 97 E300D
 

I would like to install a plate or SS washer without the hole it, to block Exhaust from entering the intake manifold, while leaving the EGR valve free to open an close.

I have 2 questions:

Will any sensors detect the lack of exhaust gas and effect performance, or throw a Code ?

Does eliminating the exhaust gas from re-combustion and hence raising the combustion temp, effect engine reliability?

I what to keep the intake clean after the mess I found earlier.

Thanks,

I do not have the answers to your questions, but I can relate to your distaste of the crud that is deposited in the intake from the EGR valve. I had the intake off of my 96E300D and I was amazed as to the amount of sludge. Thankfully it had not turned hard as is the case in a gas burner. I could not imagine trying to chisle that stuff off of an aluminumum intake and head. I would suspect that the computer would not throw a code becaule it only reads whether the valve is open or closed. as far as performance I would be curious about that. How many miles do you ahve n your 97, and have you had much trouble with it?

The Car has 67K. By the looks of things you are way ahead of me by some 200,000. That is impressive to say the least........ What your secret?

I have long wanted a diesel Benz, nearly picked up an 80's 300D a few times, last month traded our 02 VW TDI in on this one. After about 3 weeks I started to get the common 96-97 surging problem. This forum gave me the info to correct the problem. I would love do away with build up in the intake and keep the "resonance flaps" free.

I have read on the TDi forum about higher combustion temps by blocking the EGR, but no one mentions the impact on engine reliability, hotter valves ect...

There is a temp sensor in the intake boot but this is before the EGR inlet, so shouldn’t detect the inlet air temp drop.

again WOW 274K on the 210, very nice.

YES, disconnecring & or blocking off EGR will cause a code and cause the IFI system to go into a "fixed" mode.

The EGR is designed to help with piston/combustion cooling.

Thanks, M.B D.OC,
I've read your many posts and I respect and appreciate your all your help and expertise.

I think a regular maintance schedule would be the best solution. Any idea how expensive the Flaps are and where I could source them other then a dealer ?

I may try the SS Washer (with the hole) trick I heard about. There was a Fly buzzing around with this one.

Thanks again,

MBDOC, great info, By the way I believe the glow plugs took care of the CEL I have been plagued with. Been two weeks since it has come on. I too appreciate all the help you provide on this forum.

97300D, I actually bought the car with 274K on it. I now have close to 282K. the secret is to buy it form the owner of MB Autowerks so you know how the vehicle has been maintained. I had an 83 #00D with a couple hundred thousand miles on it it was fun too. This car is probably the best car I have ever owned. you should really enjoy it.

M.B. DOC,
I hate to keep beating a dead horse, but I'm still curious as to "exactly" how the ECU would detect the following:

Keeping the EGR, it's wires and vacuum lines connected, attach a small air filter to EGR intake pipe, and block the exhaust from the down pipe. This would then allow the EGR valve to open and close letting in Fresh Air rather then exhaust into the intake manifold. Unless there are sensors which could detect the drop in temp or similar gas sensor to a O2 sensor it should work. I may be missing the obvious. I just hate the idea of clogging things up with this soot and goo.

Thanks

There is actually an intake air temp sensor just above the EGR valve. I do not know if it is that sensitive though.

I'm not sure how the computer detects the EGR valve operation, but I do know it is very difficult to "wire around". Just clean the intake as required and use synthetic oil.

A clean air intake for the EGR won't fool the computer, it's looking for a reduction in combustion temp.

Peter

The Air temp sensor is up wind of the EGR intlet, at least it apears that way on the 97 E300.

If the senor reads the air temp before the EGR then fresh air through the EGR would not be detected ??? I'm not looking to to rewire or fool the system, just feed the erg fresh air rather then soot filled exaust.

MB D.O.C. please help to enlighten us.
 

MB D.O.C.

Regarding the intake system and EGR function on the 96-97 E300

Could you please enlighten us on how the system works. This is turning into more of a thought experiment or lesson then anything. What is the logical chain of events that occurs. What sensors feed what information to the ECU and how does each system depend on the reading from each sensor. I also have to wonder if companies like "upsolute" make chips for 96-97 non turbo cars and if the ones for the 98-99 cars disable some or part of the egr process.

If you are willing to teach, we are surely willing to listen!

I have also remove all the flaps and throughly cleaned then. It is important to note that upon close inspection I could see where one of the flaps left marks on the manifold indicating a possible fluttering effect during a bind. I noted that thoroughly cleaning the area where the butterfly valves moved within the manifold was important. This ensured nothing would effect it's smooth operation. Problem is now solved but I'm interested in the process and like to tinker.

This is what I have read regarding the 96-97 606 engine.

A three-stage intake system on the E300 Diesel is the first ever incorporated into a production diesel automobile. It incorporates six intake runners feeding through a butterfly valve into a twin-pipe resonance manifold, which is divided by a second butterfly valve. The runners and resonance manifold lengths and volumes are tuned to give three torque peaks at 2,400, 2,900, and 4,000 rpm.

EGR system is monitored(constant) thru change of vacuum change in the intake manifold system.
The EGR valve itself is monitored thru it's sensor by voltage changes.

You are correct in the way that the intake runner length is varied for more HP in the upper range.

what is the engine doing?? What are you trying to fix?

Nothing I fixed the stuck flap issue.

I'm merely interested in better understanding the how a system detects the actual EGR operation. And would like to make a Mod.

This is my what if "

Keeping the EGR, it's wires and vacuum lines connected, attach a small air filter to EGR intake pipe, and block the exhaust from the down pipe. This would then allow the EGR valve to open and close normally letting in Fresh Air rather then exhaust into the intake manifold. No change in Man Press, unless it can detect the ambient pressure as being different then that from the down pipe.

Unless there are sensors which could detect the drop in temp or a similar gas sensor to a O2 sensor, it should work. I may be missing the obvious. I just hate the idea of clogging things up with this soot and goo.

I do run Delvac1......

But it does . .
 

:)

I couldn't believe that my 2002 TDI would throw a code when I disconnected and plugged the vacumn line to the EGR,
but it did, and when cleared, would do it again everytime.

So I must assume the same would happen to me on my '99 E-300 DT if I were to disconnect the EGR also? :confused:

:D

Nope, not disconnecting the EGR..........only feeding it fresh air.

Look at M.B.DOC's signature - "27 YEARS DEALER M.B. Shopforeman." Having him teach you how to disable your EGR is illegal and probably not worth risking his career.

You seem to have a plan. Why don't you just try it and see if it works?

BTW, that option wouldn't work on a VW TDI because the EGR is after the turbo so the positive pressure would blow air out. I haven't looked at the 99 MB to see how it is plumbed.

Understood.....I certainly didn't mean to offend anyone.

It's more or less just a interest then anything else. I'll post results if I attempt anything. It will of course be for off road use.

I just sold my 02 TDI loved the car didn't feel like doing a timing belt every 80k though. Check out the TDI Forum and the Epsilon device. However this Mod would actually work on the TDI since the EGR Valve is closed when the manifold boost exceeds that of the ambient air. So Turbo or not it is possible

As for your 99, you could chip the car, it should make serious mods to you EGR operation, check out upsolute. Their ECU chips run around $350 installed and are impressive on turbo powered cars, had one in my TT went from 225 hp to 252 hp and 280 NM 338 NM.

A 99 Mercedes E300 will go from 177 hp to 205 hp and 330 NM (243 ft / lb) to 378 NM (279 ft / lb). Yep 280 ft/lb's of torque. And increased MPG too!

[B]A breath of fresh air[/B]
 

Tinkered with the car last night................A breath of fresh air . She runs nice and clean with no other issues. I figure just the CCV oils will help keep the resonance valves lubed and free.

If anyone would like to see pics, email me.

Now I just need to figure out how to mount the Tahoe wheels on the Benz since she is for off road use only.

Love this fourm. :D

:D

That's all well and good if you can get the local So Cal UPsolute rep to do the work, or anyone else for that matter!
He delayed for over two months (couldn't get a commonly available chip!) and then the latest excuse was that he had to help someone evacuate because of the fires. This was after claiming that he hadn't received my email verifying the appointment he'd offered me and giving me only a few hours notice. If I hadn't checked my emails, I'd have driven the 40 some odd miles to his house to find him gone. Very independent to say the least. Writting to the head guy in N C, I received no answer at all. They plain just don't give a dam, and I cannot trust my expensive ECU to those types!
BTW, the charge was to be $425. And I think only the boost is raised, as there is no electronics to the injectors or pump as there was in my TDI.

Speedtuning charges only $275.

Good to hear that you were able to block off the action to the EGR, and not set a code. I'll have to give that a try. Of course for off-road purposes only, when I go cow-trailing it!:rolleyes:

:)

Well, this is the result.

The engine draws clean air through a Breather Filter rather then soot filled exaust. The entire mod cost 11.00 for the filter at Auto Zone. Engine seems to have more power in all ranges.

Top view

I feel there is no need for apologizes on this board. After all, we are all junkies looking for a place to talk about technical stuff.

I have to admit your "breath of Fresh air" is a very simple yet effective idea that has me thinking why do people spend so much time trying to disconnect the EGR when you can just plumb it to suck fresh air?

Bravo 97 E300D!!!

Please keep up us updated with your findings.

As long as all the sensors are "upwind" from the EGR there should be no problems indicated for the ECU to adjust.

Has anyone tried this filter on a 98-99 e300td yet? I assume it would replace the rubber covered pipe,coming out of the head cover. The line that feeds into air intake just ahead of the turbo.

ready-ronnie - I think the tube you're talking about is the crankcase ventilation line, not the EGR. The EGR on ours is under the intake manifold. The simple filter idea wouldn't work, because the EGR is located in the high pressure portion of the intake (after the turbo). It would blow air out instead of suck it in. :(

It will work.......
 

Rick Miley,

I think you should better understand the process of how the EGR valve functions before denouncing the idea on a Turbo. It will work....... Remeber the EGR Valve is still fully fuctioning on this mod.

If you were correct and it would be blowing air out of the "breather filter" then it would also be blowing air out into the exhaust manifold as well, when hooked up in the stock configuration. I don't think the engineers would what to "Create" a manifold leak.

Look at it this way, in order to blow air out the EGR valve and hence out the filter. The intake manifold pressure needs to exceed that of the ambient air pressure 14.7 PSI (sea Level). This may be the case at High RPMS but again at high RPMs the EGR is closed.

To see it another way there is really no such thing as "suction". In an engine the pistons do not really suck air in through the intake, but rather create a partial vacuum in the cylinder and the outside air pressure rushes in to fill the vacuum at 14.7 PSI. Also as valves open and close faster at higher RPM's there is not enough time for all the air to fill the vacume in the cylinder to make 14.7 PSI a turbo or supercharger can help to balance this out, in an over booted engine it can pump in more then 14.7 PSI. Again the EGR valve would most likly be closed.

In aviation most turbos do not over boot an engine, the proccess is termed turbonormolizing, as the air get thinner as you fly higher the turbo creates the same manifold pressure as at sealevel.

Ok I get carried away.....

The location of the EGR valve on the turbocharged engine is "after" the turbo in the intake stream, but "before" the turbo in the exhaust stream. So the exhaust is under enough pressure at that point to overcome boost pressure on the intake side. And don't forget they're using both Mass Airflow Sensor and Manifold Absolute Pressure sensor to monitor this engine. It is a more sophisticated setup than the non-turbo.

I believe your talking out of your pie hole. But (no pun intended) if you believe that the turbo can sustain over 900 mbar which is 13 psi of "positive pressure" as 3.0 liters of cylinders request that air, and lets not forget the EGR is "CLOSED" at this time, then you may be right. 900 mbars is not allot on a turbo, 2200 is allot.

But again lets state known facts not assumptions. Go to the numbers and determine if the intake system really is under "positive pressure" over 14.7psi while the EGR valve is open. I would love to tell you your are wrong but I won't claim to know until I know. I would hate to inhibit creativity just to sound like a know it all. After all Turbo's do pump allot of hot air.

At any rate the fight is not over they do make one way check valves. Also don't these cars have "DEVERTER VALVES"

This is fun, almost more fun then working on a car.

1 millibar = 0.0145037738 pounds per square inch

Getting closer to the truth:

All these forced induction engines are under 1 bar or 14.7 psi ,so they would be sucking air through the EGR filter not blowing.

Not a 98-99 but it does give a comparission:

What turbo was installed on the 98-99 ?

83 300 sd Engine 617.95 Turbo Diesel
Turbo -Garret TA 0301

1000 rpm/100 mbar - 4200 rpm/700-730 mbar.

And the 2003 (Twin supercharged Gas) E55 AMG engine makes a towering 469 hp and a massive 516 lbs.-ft. 0-60 mph in 4.5 seconds.

It Generates a maximum of 11.6 psi (or 0.8 bar) of boost pressure. .

97E300D


How is the EGR mod working out. I'm thinking of doing it soon myself

The Mod works Fantasic............. I only wish I had done it sooner. It is such a simple fix

I looked at your website. Nice rims where did you get them, E420's ?
I'm in the process of getting a second set of the stocks so I can run a full set of Snow tires. Right now I only have them on the rears but the slight tire size diff seems to throw off my Cruise Control (wheel speed sensors).

Anyone got one extra stock 10 hole E class rim 96-97

What did you cover the exhaust manifold end of the project??? and what type of tape did you seal the filter to the metal hose???

I'm doing this this weekend---

Hoping that my "used" oil will be less "tarrish" in color when I replace it....you think??

a2

I used just standard electrical tape but I would like to use a different method sice I suspect Tape may eventually degrade with the heat that is present in the Engine Bay. I'm sure a trip to home depot could give me an idea or two. I used a piece of sheet metal cut in a small circle and use the orginal clamp to hold it in place. No blow by. I would recommend trying a copper pipe cap used in plumbing to fit over the manafold flang and just tap it in place and crimp it over the flang. There are many methods to blocking off the exaust flang I just put the sheet metal in place.

Thanx for the complements.... The rims are replica AMG monoblocks, found on the E55. They are 18x8 all around with a set of Continental ExtermeContact all-seasons that seem to be working out a lot better than I thought in these wintery conditions. I bought them from www.Bekkers.Com.

I will be having my emmisions testing coming up soon, within a month. I will wait till I get that done, just as a precaution.

How did things come out? Any pix?

Performed the mod tonight....

http://www.michakaveli.com/egrmod/egrmod_8.jpg

did it
 

I've having BAD surging issues wqith my w210 D nonT. First, I cleaned the cross over tube and scrubbed the hell out of the flaps.Surging didn't stop. I was 1 p***** off shade tree-er.

Well, it was 1:00 pm and the ambient temp was not that hot @ 97 degrees so I went ahead and did the mod. Bought the breather filter in your previous pic but instead of using electrical tape, I superglued the connection. I don't want to run the risk of it popping off if the tape losses it's grip due to high temp.

NO SURGING !!!!! NOT @ 45,55,or 60!!! Phenominal smoothness.

Took a while but well worth it. I appreciate the info 97E300D

EGR with a breath of fresh air
 

Are you guys still pleased with the mod using the filter?

Had my E300D four months and considering the same.

TIA:cool:

Yep...I cleaned out my manifold with a product called Chem Tool B12. Best stuff out there at Autozone. Went through all the flaps the egr valve and cleaned off the sensor in the rubber hose. Reinstalled everthing and she runs great no more surging... ever. I believe the violent surgging problem ruined my trans, I was luckly my extend warrenty covered the coastly repair. I would not dirve a car for a long time with the surging problem since it can put a lot of stress on the trans and wear out the clutch disks.

I had intended to run the egr fresh air hose back to the airbox. I even had it set up once, worked fine, but figured why put a hole in the air box when it works fine with the small filter.

Again I wish a 98-99 Turbo user would attempt the mod, and post the results......

Thanks for the quick response.

My surging is minimum at highway speeds for 10 seconds about every 3 weeks.

I need to clean the intake. Have you seen directions on this process?

Is it just removing the intake manifold after removing the hoses etc?

Mechanical engr here so not a problem with a DIY. but some printed direction in detail would be great.

Shoot me your your email address (IM or just post it) and I'll send you an ofto.com album link. I took alot of pictures of the process intending to make up an FAQ. I assume the picture should give you an good Idea.

It's a very simple process of a few 10mm bolts, allen screws, and the hose clamps.

97E300D you have a PM. Thanks, Bob

Oh what the heck maybe others can use the pictures:

Link url: www.ofoto.com
username: diesele300d@yahoo.com
password: 97E300D (note the CAPS).

I would love to create the DIY FAQ for this mod.

I also took some photos of the technique to clean out the Climate Control Fan if you ever feel it is not sensing the correct inside tempature or it makes noise.......

EGR revelations
 

Did it but made some changes. Turned the pipe around so as to place the filter higher up and away from the exhaust heat. Also realized the the heat is going to melt your tape adhesive sooner rather than later. Solution: the crimp clamps used on the pipe fittings. Get a third one (will do in the am since MB dealer is open till noon on Saturday). You will find that your breather filter when placed into the pipe flange, will be held snugly in place with one of those clamps. Problem solved. Also I used some of the red liquid gasket under the seal on the exhaust. Crimped it down moderately so as not to have as much metal to metal as possible, and will wait until tomorrow pm to crank it up. If I can't get the clamp will jury rig the filter until I can get one. Thanks again for doing the ground work on this one. Since the egr is closed during most of the driving, I don't think the computer is going to miss the charcol air much. It is absolutely assinine that the epa ever required the egr on the diesel cars, as it is a prescription for early death. Fortunately the older models plugged up without detection and that's what probably allowed the cars to avoid emphysema in their old age. I did not take off the intake and clean the other valves and hope that the continuous clean air will allow me a long time before I have to do so. Thanks again, Harvey

There is absolutely no need for any adhesives or other gizmos.

All that is required is 3/4" heater hose, cut to a length that will slide and fit into the EGR tube to a point that it will no longer go in, on the other end using a clamp attach the breather filter and viola. DONE!

I've been running this setup for the past year with not a single problem. Hope this helped ;)

Yeah thats what I figured. Nice modification. These are the old pictures. I now just attach the filter right to the end of the EGR, no hose at all. We should create a nice How-To for others. I wanted to route the hose like you use, just right back to the bottom of the air box. In fact I had it all set, just stopped short of making a hole. Since my current method is still working I fiqure why fix what is not broken. I do agree the heater hose is the best an easiest solution. I just do what this car loves to do.... cruise for 2 hours a day at 80MPH +.

Again please someone with a turbo please.. try the mod !

Wrong Statements Regarding Turbocharging
 

97E300D There were mistakes in the following paragraphs concerning turbocharging.
Member
It will work.......
Rick Miley,

[#1.....I think you should better understand the process of how the EGR valve functions before denouncing the idea on a Turbo. It will work....... Remeber the EGR Valve is still fully fuctioning on this mod.]

[#2.....If you were correct and it would be blowing air out of the "breather filter" then it would also be blowing air out into the exhaust manifold as well, when hooked up in the stock configuration. I don't think the engineers would what to "Create" a manifold leak.]

[#3.....Look at it this way, in order to blow air out the EGR valve and hence out the filter. The intake manifold pressure needs to exceed that of the ambient air pressure 14.7 PSI (sea Level). This may be the case at High RPMS but again at high RPMs the EGR is closed. ]


[#4.....To see it another way there is really no such thing as "suction". In an engine the pistons do not really suck air in through the intake, but rather create a partial vacuum in the cylinder and the outside air pressure rushes in to fill the vacuum at 14.7 PSI. Also as valves open and close faster at higher RPM's there is not enough time for all the air to fill the vacume in the cylinder to make 14.7 PSI a turbo or supercharger can help to balance this out, in an over booted engine it can pump in more then 14.7 PSI. Again the EGR valve would most likly be closed.]

CORRECTIONS BELOW:

#1 Rick Miley is right. Your device will not work on a turbocharged engine. If you hook a pressure gauge to your non-turbo intake manifold you will get a slight vacuum reading. The EGR valve on a turbodiesel is only activated at periods of low boost which is still above atmospheric pressure.

#2 There is positive pressure in the exhaust manifold as the gasses are held back by the energy needed to turn the exhaust side of the turbo. There is also positive pressure in the intake manifold of a turbodiesel. hook up a gauge and see. THIS PRESSURE IS OVER AND ABOVE AMBIENT AIR PRESSURE. IF WHAT YOU HAVE STATED ON OTHER DATES ON THIS TOPIC IS TRUE THAN WHEN YOU HAVE 14.7 POUNDS OF AIR IN YOUR TIRES THEY WILL BE FLAT. A TURBODIESEL HAS POSITIVRE PRESSURE ( ABOVE ATMOSPHERIC) IN THE MANIFOLD. A flat tire has ambient pressure in it!!!! OK?

#3 The intake manifold pressure INDEED EXCEEDS ambient pressure.

#4 There is no vacuum in the cylinders of a Turbodiesel due to the positive pressure created by the turbocharger. Therefore the charge air is forced into the cylinders at a pressure above atmospheric pressure along with additional fuel. How else does a turbocharged engine make 40-50% more power?

Therefore your device will not work on a turbodiesel

Really...
The turbo has a boost pressure above 1 bar or 14.7 PSI ?

WASTEGATE OPENS AT .9 BAR

I found these numbers on the turbo charger. Boost Pressure/Wastegate Pressure: .9 bar (13.05 psi). I take it this is "PSIG" boost which would then be 13.05 psi or 27.75 absolute? If that is the case the I stand corrected but I'm not convinced my friend. Read the boost gauge on a car when it is not running. It reads 1 bar.

Now Read this:
http://www.intendedacceleration.com/tip_1.html

Q. How else does a turbocharged engine make 40-50% more power?

A. Well it is because it supplies the combustion chamber with more air for the fuel/air detonation. My post was not that far off when I said "
as valves open and close faster at higher RPM's there is not enough time for all the air to fill the vacuum in the cylinder to make 14.7 PSI, a turbo or supercharger can help to balance this out, in an over booted engine it can pump in more then 14.7 PSI."

It's all relative the air pressure running through the turbos vains on each side of the engine will still move and pressurize air. It just is lower pressure then that of what is outside. You can still feel the air blowing on a mountaintop; it just takes a higher speed to feel the same as on the ground.


The 14.7 psi is absolute pressures so yes a flat tire is 1 bar and an inflated tire is bar + 32 psi or 46.7 psi absolute pressure. Take a flat tire with no leaks around the bead up 20,000 agl and see what happens. Of course it will be flat when you hit the run way again.

Try this on for size. Fill an empty paint thinner can with 1/4 inch of water heat it until the water is seaming out the opening. You have now displaced the air. put the cap back on and watch what happens when the water condenses back to liquid and leaves a vacuum in it's place. The air pressure around it crushes the can.

When they say the turbo is .9 bar I take it as meaning .9 Bar unless it means .9 Bar of boost above 1 bar. I may be wrong though, just prove it, Let keep this a friendly debate. Typing all caps is sometimes considered rude.

From a technical article at superstreetonline.com:

A turbocharged engine revolves around one central idea, and that is boost. Boost is defined as the increase in manifold pressure above atmospheric pressure. So what the hell does that mean?

Basically, boost is a gauge of the amount of charged air pressure produced by the turbocharger. As boost increases, more charged air is being force-fed into the motor and more horsepower is being made. Boost levels are usually measured in pounds per square inch (psi).

Full text of the article can be found here.

Automotive boost gauges typically read 0 at atmospheric pressure, and boost is always measured above atmospheric. This is even verified by the article you linked to above: "The BAR gauge in the Audi is an absolute pressure gauge and it takes into account the atmospheric pressure. It is an international unit of pressure that is used in most countries. It is equal to 14.5 PSIA or approximately 1 atmosphere. This is why our gauge read about 1 BAR when the engine is off at sea level.
...
Atmospheric pressure can also be ignored when it comes to BAR. Sometimes a european tuner will say the engine is boosted to... or is running 1.1 BAR of boost. In this case he is referring to what we would call 15.9 PSIG boost. He could also say the engine runs at 2.11 BAR."

Notice that they are talking about Audi. Mercedes-Benz ignores atmospheric pressure, and starts the gauge at 0, not 1. Perhaps you will believe the Mercedes-Benz manual for the 300D. The procedure for checking boost pressure can be found here.

Well it sure looks like you got me then :)

I interpreted 1 Bar to mean Barometric pressure not Psi. 1 Bar of boost , "boost" being the key word, means over sea level presure.

But does the ERG valve open when the engine is "Boosted". I thought the EGR valve opened only at lower cruise RPMs when the Turbo was not spooled up. So at what rpms or Man Pressure does it open? The intake is not always boosted is it?

I don't see how attaching a breather filter onto the line feeding the EGR assembly would cause such a "production" for the engine, not thinking theoretically just practically at this point.

Mind you I am keeping this extremely simple, but the EGR valve is exactly that, a valve. IF the EGR valve was to say be open, partially or fully while the turbo is creating boost, that would mean that pressure would be escaping back into the exhaust manifold right?

The amount of flow into the EGR is dependent upon the vaccuum that the cylinders create. It makes no sense for the EGR valve to be open while the turbo is creating boost. The turbo would have to work proportianlly harder to compensate for th eboost lost through the open valve.

If you ever look at the flap on the flap of a non-turbo OM606, you can see that as soon as the rpms start to increase above idle, the flap opens wide to allow air from the airbox, not from the EGR.

I looked at an OM606 turbo this afternoon at the New England GTG. This post is a result of my primative findings. What the worst that can happen while trying this experiment, setting a CEL that will clear after putting things back to normal?