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1995 E320 Wagon, 2002 S430
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Discussion Starter #1 (Edited)
I finally got around to cleaning out my EGR valve tube! -- boy am I glad I did it and boy am I glad for the org and the resource that it is for these types of procedures. I think I read every single post dedicated to the very subject of EGR valve tube cleaning and it paid off. In the end, I blew out a massive mess of rusty goopy obsidian carbon tar resin that had been broken up by several applications of carb cleaner, industrial grade citrus degreaser, speedo cable roto rootering, and compressed air. I could not blow a single pocket of air through the EGR valve tube until this black goober was expelled. I mean it must have been 3 inches in length and completely solid (right at the juncture where the tube bolts on to the combustion chamber side of the engine). it was music to my ears when I pulled trigger of that air tip and heard the sound of a goober mortar firing a deadly round of toxic black resin, followed by the sound of compressed air whooshing freely through a clean hollow tube. It was the sound of triumphal victory!

My Mercedes mechanic told me how the ecu retards the engine timing when the EGR system is not operating as it should and makes things run really rich; fuel economy suffers along with performance, emissions, responsiveness, idle, etc. I am very much looking forward to putting everything back together again tomorrow and firing it up.

Oh, and while I was in there with good lighting, the right tools, and armed with a good night's sleep (9 hours), I managed to discover and fix several other things in the process. I discovered a vacuum hose that was disconnected inside the intake tubing cave of darkness (yes, that is the official name). I also discovered another vacuum tube that was deteriorated at the connection juncture and likely leaking; I cut a new length of brand new tubing and replaced it. While underneath the car I discovered what was causing the rattling going over bumps and undulations at low speeds. The sway bar on the driver's side was moving around inside the outer sway bar bushing at the wheel end (anyone have the official name?). So as a temporary fix, I screwed/wedged a two inch screw in between the swaybar itself and the bushing to remove the play and rattle. This will do until I can order and replace this bushing; all the other bushings on the swaybar for that matter (both brackets too as one of them is completely broken).

So this procedure revealed and allowed me to resolve a whole host of other problems I was having with my Merc. I am usually not so lucky, in fact, typically, something will brake or go wrong during a procedure, thus creating an entirely new set of problems. I guess it must have been my lucky day.

I will be posting a sticky on the EGR valve tube cleaning procedure as I believe there are some important details that will help many who attempt to undertake this project. Not that the other posts on the subject are not adequate, my post will aim to consolidate this knowledge and will include pictures as well.

For anyone that has not done this yet and you are getting the CEL code of EGR valve not functioning, DO IT! It is not difficult at all if you are armed with the right tools and the right knowledge.

-Soundquest
 

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93' W124 E36 AMG ; 71' Cadillac Eldorado ; 07' S211 280 CDI
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I cannot wait for the sticky with pics and procedure in points.

I really want to do the same thing on my M104, even though it hasn't reached 120K yet.

Did the whistling sound, that You were talking about go away? What was it caused by? EGR or vacuum lines?
 

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1995 E320 Wagon, 2002 S430
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Discussion Starter #5 (Edited)
I cannot wait for the sticky with pics and procedure in points.

I really want to do the same thing on my M104, even though it hasn't reached 120K yet.

Did the whistling sound, that You were talking about go away? What was it caused by? EGR or vacuum lines?
I was hoping the whistling sound would go away with those connections being brought back together but it was not to be. My Merc talked back to me and said "I'm not going to let you get off that easy, you're gonna have to work for this one."

I actually did a video of the procedure and will be posting it on youtube. After that is posted, I will do the written instructions with pictures to follow (have been EXTREMELY busy all of a sudden as of late so it will be here and there as I have time unfortunately). There are some key things to making this procedure go smoothly -- the video mentions those things. They are as follows as far as the tools go:

Tools and supplies you need:

1. stubby 3/8" vertical swivel socket wrench
2. 10mm socket
3. 10mm ratcheting box end wrench (very important)
4. 6" socket extension (with wobbler would be helpful but not necessary)
5. 3/8" 90 degree air tool (and air compressor of course)
6. speedometer cable
7. Air nozzle (air gun)
8. vacuum hosing - 2 feet will do
9. Carb and throttle body cleaner
10. Shop light or luxeon star headstrap spot lamp (trust me, you need good light)
11. 19mm open ended wrench
12. Can of PB blaster or similar for getting stuck nuts/bolts free
13. Cordless drill (set to high rpm)
14. Needle nose pliers (for fraying the speedo cable at the end so it agitates and bores through the blockage)
 

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I did this just a week ago roto-rootor speedo cable and all. i wish i had seen this post; i would have used compressed air too. Now im wondering if i should sea-foam the intake since this blows goob back in there dosent it?
 

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1995 E320 Wagon, 2002 S430
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Discussion Starter #7 (Edited)
Instructional Video on EGR Vavle Tube Cleaning

I did this just a week ago roto-rootor speedo cable and all. i wish i had seen this post; i would have used compressed air too. Now im wondering if i should sea-foam the intake since this blows goob back in there dosent it?
Yes, that caustic black goop went right in to your combustion chamber side -- I would indeed cycle some Seafoam through. Please post your results and PM me and let me know how it goes if you wouldn't mind.

For all those wanting to attempt the EGR Valve tube roto rooter process in the future, please watch this video first as you may find it useful. I think the technique(s) I am using are a combination of "best practices" put in use and posted here by fellow members (cjscopp and White_Knuckles, others) plus some invention and creativity on my own part. You will notice in the demo how much slack is in the cable when I am demonstrating the roto rooter; that is just for demo purposes, make sure your cable is only about a foot outside of the tube at most as you don't want it to tangle around things in your engine at high speeds (it will bind, twist, and bend, you do not want that).

Make sure you actually go to the YouTube site to view the video or the quality will be negative and you will not be able to read the text in the video which is very important.

Enjoy.

 

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1995 E320 Wagon, 2002 S430
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Discussion Starter #9
I would suspect your EGR tube is gunked up already at this point, but there is a good chance it is not COMPLETELY bocked.

The good thing about this problem is that it is very east to test...if you have an air compressor or access to one. Simply disconnect the EGR Valve and blow compressed air through the EGR valve tube (the long tube, the short tube needs to come off with the EGR valve). If you get any backflow at all, it's time to get down and dirty -- but be encouraged, it's not that difficult to clean if you use the method and tools outlined in the video.
 

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Late reply but oh well... yup i sea foamed it afterward s and it dose make a difference, i use a vacuum line on the intake side. Let it draw some in, shutif off let it sit and then run it until it stops smoking.
 

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1995 E320, 2002 E430
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EGR tubing cleaning

Thanks for your posting Soundquest. I found your video on YouTube and it was a great help. I couldn't find it on this forum's Search, probably from the title you had posted it with., and it popped up on Google. Do you think it should be a sticky?
I did have success, and have two suggestions. One, watch out for knocking the tube flange gasket off- the one near the throttle body. It's a bear to get back on.
Two, on my 95 E320 that same section of tubing has a clamp that holds it to the bracket at the bottom of the oil filter. It's hard to see and not the easy to get at. Loosening the allen head bolt makes it easier to move the tubing out of the combustion chamber when you're ready to blow that sludge out.
I let the carb cleaner sit overnite and still had a bit of a problem blowing it out after the rotor-rootering.
My miles are at 250k, and the previous owner had the dealer do it at 187K.
 

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1995 E320 Wagon, 2002 S430
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Discussion Starter #14
Thanks for your posting Soundquest. I found your video on YouTube and it was a great help. I couldn't find it on this forum's Search, probably from the title you had posted it with., and it popped up on Google. Do you think it should be a sticky?
I did have success, and have two suggestions. One, watch out for knocking the tube flange gasket off- the one near the throttle body. It's a bear to get back on.
Two, on my 95 E320 that same section of tubing has a clamp that holds it to the bracket at the bottom of the oil filter. It's hard to see and not the easy to get at. Loosening the allen head bolt makes it easier to move the tubing out of the combustion chamber when you're ready to blow that sludge out.
I let the carb cleaner sit overnite and still had a bit of a problem blowing it out after the rotor-rootering.
My miles are at 250k, and the previous owner had the dealer do it at 187K.
You are most welcome.

Good additions. In time, with everyone contributing, this process will be jet set for people that wish to undertake the same task. It's the little things, the small details that help the most in the end. I believe the video and procedure were posted to the stickies last year.
 

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My writeup for this procedure.

Raise hood to upright position.

Disconnect battery terminals.

Ask yourself if you really want to do this.



Remove clips on air filter housing.







Loosen clips connecting air mass meter housing to air filter housing.






Remove/ loosen hose clamps on flexible hose







Remove electrical connection for air mass meter.




Remove air mass meter with flexible hose.

Loosen 5 nuts on exhaust manifold heat shield.






Remove heat shield.
 

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1995 E320
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Locate 10 mm bolts on EGR valve






Loosen 10 mm bolts on EGR valve






Loosen 19 mm bolt holding EGR pipe to EGR valve.


Loosen forward bolt on intake side EGR pipe from LF fender. Use wobble extensions or
elbow joint.




Jack up vehicle at LF tire. Use a jackstand to hold the vehicle up, not your cars jack.




Remove drip pan/ sump guard from under the vehicle.


Locate 10 mm bolt on rear of intake side of EGR pipe.




Loosen rearmost bolt with ratcheting wrench (that is pretty much all that will fit.)




Loosen 6mm allen head bolt on oil filter housing.

Move pipe away from intake (mind the gasket falling off.)


Spray inside of EGR pipe with carb cleaner from exhaust side.






Let sit before rooting with speedo cable.


Repeat last two steps as necessary until pipe is clear.


Reinstall all parts in reverse order.
 

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1985 190d German Cockroach 2.2 M5 395k miles 2004 C240 Wagon Non-4-matic
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Definitely loosen the allen bolt tab on the oil filter housing

Yeah did this. Loosen the allen bolt on the oil filter housing and the bolts on the driver side of the engine, and well as on passenger side.

When I did mine at 185k, there was 6 inches of solid sludge there.

I had to use a dremel tool with a section of speedo cable to drill it out.

Because I carefully angled the tube loose on the driver side, once the allen bolt was removed, I was able to let all the black tar crap fall on the ground, instead of into my combustion chamber!

Basically, I was looking up into the loose tube while I laid on the ground. The butterfly is where the build up happens.

Loosen the allen bolt, free the tube, and clean it out. Compressed air did NOTHING for me.
 

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I still have high NOx.

I need some help here guys. What could it possibly be?

Recent tuneup, oil and filter.
Just did the EGR pipe a coupla weeks ago.

Still got a 4.92 where the standard is 2.00 for Nitrates of Oxygen. Before the EGR pipe rootering it was a 5.03.

Passed the other two. I reckon if it was a bad cat it would have failed those.
 
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