Easy Reversible EGR delete, 95,96,97 Non-Turbos - PeachParts Mercedes-Benz Forum

Racekar · #1 04-12-2008, 04:24 PM

I don't want to start a war about the ethics of this, I am just presenting what I have learned, if others want to try.

Sometimes it seem like these cars are forgoten about with most working on the W123's and early turbo W124's. But our engine seems particulary venerable to soot and crud blocking the intake manifold. Also non-turbos do not have as much HP and any performance benefit is welcome.

There are 3 parts to our EGR system.
1. The EGR valve it self and it's attachment to the intake
2. This model has a baffle in the intake, This baffle moves by vacume linkages to draw fresh air from the air box or exhaust gasses from the EGR (or a combination of the two)
3. There is a mechanical linkage that attaches from this baffle to the throtle linkage and helps hold the valve open under wide open throtle.

So what do we want, the EGR to remain closed. If we just plug the vacume line to the EGR it will not open, but because of the baffle we will still try and draw air from it, restricting airflow and hurting power.

I have worked out a way to make it all work, and it can be changed back in 5 minutes if you need to get an inspection

First block the EGR vacume line (the line going into the top of the EGR valve) with what ever fits. I used a bolt with the head cut off and shoved it into the line and then reconnected it to the EGR so it looks stock.

Next disconnect the rail that connects the baffle and the throtle, in a moment you will see why.

Next pop off the vacume regulator connection to the baffle, it will just sit there and move during operation but not affect the baffle.

Now I used some safety wire and fixed the baffle in the fully open position. Since the EGR will not open and the other mechanical methods of baffle movement are removed the engine always gets fresh air from the airbox.

I have included some pictures. I have noticed that the car has more pep under part throtle operation and does not have to downshift as often to accelerate or mantain speed on grades. I think it will make more difference once I remove my manifold and clean out all the crud that has built up. I think this may also work for the 98-99 turbo models but it may throw an error code because your engines have more electronic feedback.

#2 04-12-2008, 06:14 PM

There is a more simple removal method available for the non-turbo 606. Put a block plate over the exhaust port and stick a small filter on the end of the EGR (Or cut a hole into the clean side of the air filter housing and run a tube into there before the MAF sensor.)

Quote:

I think this may also work for the 98-99 turbo models but it may throw an error code because your engines have more electronic feedback.

It will put them into limp mode if any of the EGR parts aren't working. Something is needed to fool the MAF into seeing a reduction in airflow when the EGR is actuated.

Matt L · #3 07-10-2008, 03:15 PM

Quote:

Originally Posted by ForcedInduction

It will put them into limp mode if any of the EGR parts aren't working. Something is needed to fool the MAF into seeing a reduction in airflow when the EGR is actuated.

That's if you have the MAF. Turbo models do. Mine does not.

Racekar · #4 04-12-2008, 06:24 PM

The idea is to make it simple, and to be able to reverse it to stock. It is difficult to block off the EGR and to cut the tube to put on a small air cleaner. This technique works, is simple, and can be reversed in 2 minutes.

curlytom · #5 07-10-2008, 01:56 PM

I saw this by chance and it sounds like it might be a better alternative to plugging the exauhst and adding the small filter to the EGR intake. This way the engine is getting a FULL supply of fresh clean air through the big intake throat ALL the time vs. a combo of clean air-box air & clean air through the small restrictive EGR port...

Racekar - Any update on how's this working out for you up to now?

Jeremy5848 · #6 07-10-2008, 05:23 PM

After I plugged the EGR ('96 E300D), I seem to remember checking that flap and seeing that it is wide open with no vacuum, so I just put a BB in the vacuum line. But to be sure, I'll check when the wife brings the car home today.

Racekar · #7 07-10-2008, 06:33 PM

I have been using it since I posted the thread. Works fine, I just changed my glow plugs and cleaned out the intake so when I check in 6 months the intake should be clean if this mod works. So far everything seens fine. I think that others have stated that it only works for 95-97 models.

Rick Miley · #8 07-10-2008, 07:26 PM

Won't work on the turbo models - we've been around that tree before:

99 E300 Crankcase Vent

Jeremy5848 · #9 07-10-2008, 07:45 PM

Quote:

Originally Posted by Racekar

I have been using it since I posted the thread. Works fine, I just changed my glow plugs and cleaned out the intake so when I check in 6 months the intake should be clean if this mod works.

When I disconnected the EGR and cleaned out the pipes, I was flabbergasted at the amount of crud in there after only 250,000 miles and three POs. All that diesel soot had actually blocked the crankcase breather ports on cylinder #6. All of the intakes were blocked to some extent. Hopefully the last time I do that clean-out job.

Jeremy

Jeremy5848 · #10 07-13-2008, 06:44 PM

After replacing the #3 glow plug (an easy job, required removal of the crossover pipe only, the old glow plug came right out, no carbon deposits on the tip at all) I checked on the flap next to the EGR valve. Apparently I had thought it was part of the resonance flap mechanism and left it operational -- how wrong I was! Thanks, Racekar.

I "turned off" that flap by putting a BB in the vacuum line to its controlling solenoid, down under the main air pipe from the filter box. That way, the entire mechanism remains intact and looks stock, it just doesn't do anything. (I would have blocked the line at the flap itself but the rubber hose there is larger and my BB fit the small Y-connector better.) Going back to stock would require only removal of the BB.

Jeremy

freesoul · #11 05-20-2009, 09:27 AM

Quote:

Originally Posted by Jeremy5848

After replacing the #3 glow plug (an easy job, required removal of the crossover pipe only, the old glow plug came right out, no carbon deposits on the tip at all) I checked on the flap next to the EGR valve. Apparently I had thought it was part of the resonance flap mechanism and left it operational -- how wrong I was! Thanks, Racekar.

I "turned off" that flap by putting a BB in the vacuum line to its controlling solenoid, down under the main air pipe from the filter box. That way, the entire mechanism remains intact and looks stock, it just doesn't do anything. (I would have blocked the line at the flap itself but the rubber hose there is larger and my BB fit the small Y-connector better.) Going back to stock would require only removal of the BB.

Jeremy

I assume this "flap" that is being referred to is the one in the air intake? I plugged my EGR vacuum line and was looking at wire-tying the flap open but didnt know if it had any negative side effects.

I had the IM off to put a new wiring harness and GPs in. There was A LOT of soot especially on the first 2 cylinders- the CCV ports were completely blocked off on those. I suspect this may be a problem with the injectors and will have them pop tested in the near future.

To clean the IM and EGR assembly I soaked them in biodiesel for 2 days and scrubbed them as far as I could get into (I removed the 2 valves with vacuum assemblies first)

To clean the intake ports on the head I made sure the valves were closed for each cylinder by rotating the head- and used a wire pipe cleaner and then vacuumed out the port with a small hose. One port was 1/3 blocked with crud.

I started it up late last night and boy did it smoke! I plan on taking it out tonite and doing a good highway burn. I'm excited at the prospect of it running better now that its all cleaned out.

markg612 · #12 01-28-2010, 12:31 PM

Most impressive!

JimmyL · #13 09-06-2010, 12:50 AM

I've had this bookmarked for over a year, and finally performed this modification.
All I can say is that it doesn't even feel like the same car!!!

I love my '95. By far it is my most favorite MB that I have ever owned. But it was a bit annoying for a couple of reasons.
First, when slowly accelerating, there was a tremendous loss of momentum on the 1st to 2nd shift. The car would fall completely on its nose. Rapid acceleration was fine.
Second, these cars are far from quick. You are constantly having to downshift in order to accelerate the car from the lower rpms of a particular gear. {for example, going 40mph in 4th required a downshift to 3rd to gain mph}.
With this mod performed, First the car accelerates smoothly from 1st to 2nd without falling on its nose. I can't begin to tell you what a huge difference this is!! This is the single biggest complaint I had with the car. The difference is amazing.
Second, in a limited test drive, I can tell that the car can accelerate from 40mph without having the jerk of a downshift.
The car is a much more enjoyable drive now!!
If you look at the flap in the intake just downstream of the air filter box, you can tell that when you are mildly accelerating and the accelerator cable is not opened up halfway or better, the flap to the airbox must be blocking air from the airfilter box and must be pulling mostly through the egr. Restricted air, less fuel I'm guessing, and no acceleration.
Now I'm curious to see what this will do to my mpg. Usually when you rob Peter you have to pay Paul, so we'll see, but the difference in how the car drives will be worth it.
Here are just some quick pics:

This is the linkage from the accelerator cable to the flapper valve that is removed.

I'm happy about this because several times a year I have to clean and lube this piece to allow the accelerator linkage to fully retract and allow rpm's to drop to normal idle.

Then here are the two lines that get the BB's. Since I have mush in my brain pan, I marked the lines with the BB's.

And finally, I tie-wrapped the flapper valve open. Not much resistance on this valve at all, so a tie wrap was fine.

This is quick to do, quick to undo and the difference makes it inexcusable for a '95 E300 owner not to perform this.
I'm just sayin'........

Kudos to Karl for starting this thread and for the info!

arcticathlon · #14 10-19-2010, 03:51 PM

since i just purchased a 95 E300d, i am wanting to do the EGR disabling mod. JimmyL i have a question regarding the pictures you showed above. i see the first line that needs to be plugged, but the second line is not so obvious. am i plugging the actual EGR device vacuum line as well? in the second picture you are pointing at a vacuum line, but i am not sure if you mean the vacuum line that is near it.

JimmyL · #15 10-20-2010, 01:46 AM

Quote:

Originally Posted by arcticathlon

since i just purchased a 95 E300d, i am wanting to do the EGR disabling mod. JimmyL i have a question regarding the pictures you showed above. i see the first line that needs to be plugged, but the second line is not so obvious. am i plugging the actual EGR device vacuum line as well? in the second picture you are pointing at a vacuum line, but i am not sure if you mean the vacuum line that is near it.

Seems like there is a solenoid looking thing down there, and it is BB's in that small diameter line with the yellow joining piece. Put BB in the smaller diameter hose.
Great mod, and SO SIMPLE.
Racekar done good.....