OGCLK320

Ok, so I just tackled this today, and really had very little knowledge about what to do. I basically researched on here and then went for it!

The EGR valve on the 320 motor is in the rear of the motor passenger side you can find pics on other threads that show location, not hard to find.

Now here is some quick background info, CEL light comes on last week and throws 4 codes at me, one of them being p0400 which is the egr valve, I cleared codes and nothing came back until a couple days ago after running my car hard on some canyon roads, I pulled the codes again and it was only p0400, so I figured since it returned after clearing last time, this must be the culprit, I did my research, and decided to go for it, because a local indy quoted me 500 for parts and labor, I opted to try it on my own, haha

The EGR valve itself is held on by two 10mm bolts, but the hose needs to be removed as well, two 8mm bolts. I had to remove a few hoses and also the intake in the rear near the exhaust manifold to be able to pull the actual egr hose out of the manifold, it goes in there about 3-5 inches and has a nice bend in it to make it as tricky as possible to get out.

After removing, I could not believe how plugged up the actual hose was the was in the manifold, as others have said, I nearly only had a pin hole of air moving through, it was ridiculous how clogged it was.

So after removing EGR valve and hose I noticed all the hoses on the EGR valve had rotted away and the gaskets were no good either, made a quick trip to the dealer and bought the hoses and new gaskets $22. and some carb cleaner $5

Went home and started cleaning the crap out of the hose and valve, the valve had a little build up, but nothing compared to the hose, I used air and a clothes hangar, (metal obviously) to scrape all of the gunk out of the hose and valve, pretty much got them almost brand new looking... took about an hour to clean them up.

I then went ahead and started putting everything back together, slowly but surely I was able to get them back on properly,

Some little snags along the way, just had to move parts out of the way, a few hoses, and the intake was the main one for me to be able to remove the hose from the manifold.

It took me about 3-4 hours with clean up and test drive.

The difference was incredible, throttle response and how much quicker the motor revs up, I can only imagine how long this has been building up, it took way to long for the CEL to come on for this, because my car has felt sluggish for ever. I have 240k and I believe this stuff had never been touched before this morning.

I saved my self roughly 450 dollars and I know it was done correctly and efficiently. I would recommend everyone doing this them selves if you are a handy person and are having sluggish symptoms or receive the p0400 code.

I hope this helps a few people, I really wish I would have snapped pics but my hand were filthy and I just wanted to get it done.

A little patience and hard work will go a long ways!

Happy Holidays!

AMG_BENZ

I am wondering, is there a manual book for a CLK? Like the good old Bentley manual for a VW...

I am not sure if your problem can happen to 4.3L and 5.5L, but it's worth to keep that in mind.

MarcusF

The manual is called the WIS.

Benz Over

here are some pictures if you want to add them to your DIY
































this is what it looks like when its off

jbenz2001

Nice pics walnut.def helps alot for the people learning about their cars and wanna save tons of money tackling the job themselves.thanks

Birdseye

I need to do this thx for the diy. Did you need a wrench for the 8mm bolts? was hoping to use my ratchet w/ articulating joint but it looks tight in there (would need to buy wrench)

Rainer

I tried to follow the direction, but now having a hang-up.

It seems to me that I have to remove the air-intake completely to get to the valve - but I cannot figure out how to remove the last part of the intake. Any recommendation or what do I miss?

Please see the pictures where I am stuck.

Benz Over

dont remove that pipe, to remove the intake you need to use a hammer and a flat head to bang out the clip after the clip is out just pull the intake towards the interior of the car

hope that helps

Rainer

Thank you for the quick response.

I think it does - basically bang the clip downwards, since upwards does not work, right?

Will keep you posted.

Birdseye

wow now I am confused, I really didn't think you had to take the intake off to do this

shaggy sr

nice writeup with pics. That's very helpful

CurYousGee

http://www.autohausaz.com/search/pro...reather%20Hose

Are these the hoses you got for this diy?

astamir

thanks for the write up i have the rough idling on my clk55 w208
so i started from cleaning the throttle body and replaced the both front o2 sensors as they werent working as showed on star
and it was fine for one day and its got worse now the revs going up and down like when you are driving it looks fine as soon as you stop the revs go up and you need to restart the engine to bring it back to normal
then i disconected the maf sensor while the revs were high nothing changed so suspecting the maf sensor going to clean it tomorrow
and thie write up pushing me further to clean the EGR valve as well

dlbehrns

Have you replaced the MAF sensor lately?

OGCLK320

I just cleaned the EGR valve on my (new to me) CLK 55 and it was not nearly as dirty as the 320 was when I wrote this DIY. I would suspect you have a bad MAF sensor and probably needs replacement. I have heard of people cleaning them and it working for a little but most of the time they need to be replaced. You can find just the sensor online for a little over a 100 bucks. Much better than buying the housing and paying double or triple that...

astamir

hi guys and thanks for a quick reply cleaned the maf sensor runs fine now but still a bit rough on idling
the rpm is on steady on 5 now on idling but you can feel it like a bid of misfiring
can that be a dirty egr valve or do i need to replace the spark plugs?
thanks again and your help is very much appreciated

astamir

here we back again guys(((( after a harsh driving today morning the problem came back the rev counter up and down i disconecting the maf wire and nothing changes ill change the air filters and clean it one more if it comes back again then replacing it
but the strange thing is no cel is on

dlbehrns

If you change the MAF you will have eliminated one of the possible causes of the problem. Could also be the crankshaft position sensor but I don't think so. Another inexpensive part to replace if it has not been done before/recently.

astamir

but the strange thing is that there is no CEL on dashboard i think if there is a problem with any electrical parts like sensors the light should be on.
the other thing this problem occurred shortly after the throttle body cleaning can it be the throttle position sensor ? that makes the revs to go up and down
i had the same problem on the cars i had before like seat 1.8 turbo automatic where the CEL was on and the revs was going up and down the diagnostic machine showed it like the MAF sensor replaced that and the problem gone
in this case no lights on that confuses me

astamir

changed the air filter cleaned the maf sensor apparently the cleaning didnt work going to buy the maf sensor

astamir

it looks like the problem is gone and as someone told me on another forum the TB needs time to reset itself so after a few days of rough idling it looks ok now , but anyway i ordered the maf sensor from ebay with 2 years warranty
so ended up with problem solved and with a spare maf sensor))))anyway looking forward for an egr valve cleaning
thanks to all of you here for your replies

astamir

unfortunately the problem is back again here the video clip of the problem can you guys please help me out?
thanks

mathewathomas

Have had the check engine light for about 3 months. Was told I possibly needed 2 front cats changed ($800+). Then after the cause code, check engine light returned. This time the cause codes were p0115 and p0400, engine coolant thermostat and egr valve, respectively. I saw this post, and printed out the DIY a few months back, but being my second or third time to work on my own vehicle, I was pretty hesitant. I finally tackled the job. After a coincidental overflow from the reservoir,
I decided to start with the thermostat (and went as far as buying the part ($36.99). (Was also told that thermostat code can sometimes tie into the p0400 code.) I needed a reliable and host answer from a mechanic, so I phoned my uncle, and he told me to start with the p0400 code, and first things first, check the hoses for any wear-n-tear (cracks, breaks, etc.). As luck would have it, there was a 5/32" diameter hose, about 5" or 6" in length, that was "holed" open at the base of the egr valve housing (the house is the smaller and in the middle bottom of the housing when viewing with the intake manifold immediately in front of you). Went to O'Reilly and picked up a pure-packaged 5/32", 5ft long house (around $5), cut to preferred length, and replaced the assembly (for the hose to the intake manifold, to reach the screws, I did have to release the MAF housing and move the larger hose out of hand's way.) Putting all parts back together, and also replacing the air filters (qty 2, WIX brand) I started the car, and received a ABS/ESP light up. The lights eventually went away (and I did have the battery disconnected for the duration of the job), and then noticed that the check engine light went away!!!!!! Through my test drive, the acceleration pushed me into driver seat, and idled well. I literally saved thousands of dollars, by checking the hoses, so thank you.

jonUF02

Next step: take apart the entire intake manifold and clean it thoroughly. All that gunk that stops up the EGR tube was previously, and is now, going into your intake manifold. The manifold has big mechanical flaps inside that change the air flow as you accelerate, they are most likely really gummed up and may not even be moving to give you the maximum air flow. See my long thread about rough idle with pics.

mathewathomas

I've been hearing the flapping valves for some time now. I have been wanting to clean it out and get the valves readjusted, but I was told that the job is something I want to take to the shop for? Is this something I could table myself? (This is the first car that I have worked on myself.. egr valve, brake light switch, MAF, and serpentine belt (idler pulley break) have been the tasks I have completed.. so needless to say, I am a newbie.)