Code P0400, EGR tube clogged i guess. HELP.

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May 18, 2013 | 08:50 PM
  #1  
I bought my 2004 ML500 (used)in 2008 and it is newly PAID OFF!! Now that its totally mine i want everything perfect. I love this RIG to death. I traveled with my family on long road trips (bought a third row seat bench $1300 to fit everyone), in snow, rain, up hill, down hill and to the marina to drop our boat. This ML is a family member not just a car. But, its sick. It has the P0400 code popping up. I guess the EGR tube and valve are dirty or clogged. I love doing the work myself. Can anyone tell or show me how to get to the darn thing. I cant believe they tucked it back behind the engine. ZERO space. Please let me know. It drives fine but, i want it to be perfect. Thank you.
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May 19, 2013 | 06:20 AM
  #2  
Remove the engine cover.

Remove the Air Intake Tube.

Then remove the EGR pipe. You will need a stubby wrench to hold the bottom nut while loosening the top one. They are two different sizes.

If the EGR pipe is not clogged you must order a new EGR Valve, There is no cleaning of the valve.

Code P0400, EGR tube clogged i guess. HELP.-egr-valve-location.jpg  

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May 20, 2013 | 09:15 AM
  #3  
Thank you for that. Iv'e searched the internet for diagrams and illustrations but with no luck. I'll update on progress as i go. Thanks again.
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May 20, 2013 | 01:12 PM
  #4  
maj. dundee, what size is the stubby wrench, 22mm maybe? the top nut seems to be 25mm, can't figure the size of the bottom. also got the star bolts off the other side, thought if i could remove that side i could see if it was clogged bad or not and it seems to have a small pipe feeding into the valve cover, i couldn't get enough clearance to get it out. gave up and put it all back together for now.
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May 29, 2013 | 08:06 AM
  #5  
Quote: maj. dundee, what size is the stubby wrench, 22mm maybe? the top nut seems to be 25mm, can't figure the size of the bottom. also got the star bolts off the other side, thought if i could remove that side i could see if it was clogged bad or not and it seems to have a small pipe feeding into the valve cover, i couldn't get enough clearance to get it out. gave up and put it all back together for now.
I can't remember the sizes, but try and remove the two bolts that hold down the EGR valve to the eng. Then remove the two bolts that hold the tube. Then being that the pipe is flexible, you can maneuver it to where you have more room to work.
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Jun 1, 2013 | 02:27 AM
  #6  
top is 25 bottom is 22 thanks, now i just need to cut a couple wrenches in half
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Jun 1, 2013 | 04:52 AM
  #7  
Quote: top is 25 bottom is 22 thanks, now i just need to cut a couple wrenches in half

You don't have to cut any wrenches if you disconnect the pipe at the engine and then disconnect the EGR valve. That will give you plenty of room to work with.
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May 23, 2020 | 08:05 PM
  #8  
Quote: Remove the engine cover.

Remove the Air Intake Tube.

Then remove the EGR pipe. You will need a stubby wrench to hold the bottom nut while loosening the top one. They are two different sizes.

If the EGR pipe is not clogged you must order a new EGR Valve, There is no cleaning of the valve.
Hi Major,
Would this be similar for 2006 ML500?
Thanks
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May 23, 2020 | 09:57 PM
  #9  
This older thread may be able to assist you with your w164
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May 24, 2020 | 07:05 AM
  #10  
Quote: Hi Major,
Would this be similar for 2006 ML500?
Thanks

Yes.


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May 24, 2020 | 12:46 PM
  #11  
Quote: Yes.
Thanks
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