I am trying to learn all I can about these cars, and saw a long thread about removing the egr, but no real explaination as to why. So, why?

I am sure most people remove them for "testing" purposes only. This keeps the exhaust gasses from recycling back through the enigine giving some pep to the engine. Do a search on "EGR" and you will find several days of reading.

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BENZ THERE DONE THAThttp://www.peachparts.com/shopforum/...c/progress.gif
15 VW Passat TDI
00 E420
98 E300 DT
97 E420 Donor Car - NEED PARTS? PM ME!
97 S500
97 E300D
86 Holden Jackaroo Turbo D
86 300SDL
(o\|/o)

To stop it from sending soot and crud back threw the engine.
Yeah mines off for "testing" to

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

The soot or carbon particles that a diesel creates (a lot) pollutes the nice, clean intake air via the EGR, thereby nullifying the air cleaner (WTH is the point with cleaning the air, if you're just going to load the air with s**t anyway.)

EGR's on diesels are only meant as a test valve. Once the vehicle leaves the showroom floor, the test is over and the valve can and should be removed or neutralized forthwith. If you want to "cool" the combustion, inject water vapor or use an intake intercooler, but whomever came up with the idea of regurgitating filthy exhaust into the engine needs to be pummeled about the head and neck untill semi-conscious.

Then again, this is just my opinion, and opinions are like...........

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1984 300D Turbo - 4-speed manual conversion, mid-level resto

1983 300D - parts car

1979 300TD Auto - Parts car.

1985 300D Auto - Wrecked/Parts.


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"If you don't know where you are going, any road will get you there". Lewis Carrol

I thought there was a good reason for the EGR, namely, to reduce pollution from the tailpipe. It's function is to send a portion of the exhaust gases back through the combustion cycle to be more fully burned. Won't disabling the EGR send more pollution into the air? Is this worth the modest increase in power or engine longevity that you might get from removing it?

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'81 300TD turbo <<sold 12/05 to another diesel nut

I guess you are probably right but then I am the person with a hole burned in the ozone above my garage from learning about A/C systems

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BENZ THERE DONE THAThttp://www.peachparts.com/shopforum/...c/progress.gif
15 VW Passat TDI
00 E420
98 E300 DT
97 E420 Donor Car - NEED PARTS? PM ME!
97 S500
97 E300D
86 Holden Jackaroo Turbo D
86 300SDL
(o\|/o)

The EGR reduces specific emissions - oxides of nitrogen, IIRC? But it increases others, or something like that. I causes massive soot buildup in the intake tracts which frequently clog the ALDA pressure fitting, killing power by ~33% or so. Even with EGR disabled the emissions are still very very good as long as the rest of your engine is in good shape, and not smoking excessively.

Here's some shots of an OM603 intake crudded up with EGR soot:

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Dave
Boise, ID
Check out my website photos, documents, and movies!

Is it difficult/advisable to disable on an SDL? How do you do it?

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Enough about me, how are you doing?

Not difficult and yes it's advisable, IMO. Use the search feature, there's lots of info in other threads. You have the same engine I do but in a 126 chassis instead of a 124. Simple way is to remove and plug the vacuum line to the EGR valve, and also the little vacuum line to the turbo (to the ARV valve). Some photos of removal are here:

http://www.meimann.com/images/mercedes/OM603_intake/

gsxr, thanks for the pics.

It appears to me that the euros do not have the egr. Am i corredt? Not too familiar with them.

Thanks

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Enough about me, how are you doing?

Plantman if you havn't done this already pull your crossover pipe and take a look inside. 330k miles is a long time to let the egr build up crap. Mine was pretty bad at 233k. My theory is that if the car is driven on the highway more and under constant boost the crap is driven deeper into the manifold. My runners were getting pluged up. I pulled off the vacum line and caped the fitting's. After I cleaned out the manifold I got a plate made that fit between the egr and manifold.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

That is correct - Euro engines, at least prior to 1990, have no EGR. I wanted to swap the Euro intake plumbing but soon found out there are way too many parts to change - entire intake & exhaust manifolds, turbo brackets, intake snorkel, front exhaust downpipe, etc etc... not worth it.

How do you clean all that crap out without dropping it deeper into the manifold? Also, does anyone make and sell a kit of the parts shown here?

Is there a downside to this? When I asked a year or so ago, the mechanics I spoke with were very heistant to endorse such a change.

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Alan Hamm
'87 300SDL 277K Miles
'89 560 SL 68K Miles

You have to remove the manifold and have it boilded out. Sometimes the boiling doesn't do squat, so you may end up beadblasting it out after that.

Order a new manifold gasket now.

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1984 300D Turbo - 4-speed manual conversion, mid-level resto

1983 300D - parts car

1979 300TD Auto - Parts car.

1985 300D Auto - Wrecked/Parts.


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"If you don't know where you are going, any road will get you there". Lewis Carrol

The EGR (Exhaust Gas Recirculation) concept was imposed upon many American cars in the 1970's. It's purpose was to reduce combustion temperature in the cylinders to reduce the creation of incomplete nitrous oxides, such as NO and NO2. It accomplished the lowering of combustion temperature by reducing the efficiency of the burning of the air-fuel mix. Great idea, huh?
Then, on carbureted (gasoline) engines, the AIR (Air Injection Reactor, GM's name for it) system, which actually appeared in the late '60's, took some of the air-fuel mix from under the carburetor (American spelling), mixed it with air coming in through a belt driven pump, and forced this mix into the exhaust coming out of the engine, usually right into the exhaust manifold. This was to reduce carbon monoxide and unburned hydrocarbon emissions coming from the engine. This is particularly "useful" in reducing the elevated level of unburned hydrocarbons created by the EGR system. For older cars without oxygen sensors and computers that use them, this crap can be removed for "testing" and greatly improves miles per gallon and power. For newer cars with such sensors and computers, your stuck with keeping them so as not to throw the computer out of kilter.
The EGR system is bad enough on a gasoline engine, it's hell on a diesel. I think most of our older diesels can safey be "tested" without an EGR system indefinitely.
John