Jun 15, 2015, 04:23 PM
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rough idle, feels like a miss
Junior Member
Joined: Aug 2012
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2005 CLK 500
Silver Bullet?
Good news, I just had the EGR replaced and it the idle is finally normal! I put about 20 miles on it in stop and go traffic and a few WOT runs. I will be putting on more miles tomorrow and keep my fingers crossed that it will remain smooth. The car seems like it is much smoother during acceleration and idles at about 500-550 RPM's. This still seems a little low to me, does anyone know the normal idle RPM's are for our cars?
Junior Member
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2005 CLK 500
Thread Starter
Junior Member
Joined: May 2012
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2005 CLK 500
Junior Member
Joined: Aug 2012
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2005 CLK 500
http://www.partstrain.com/ShopByDepartment/EGR_Valve/MERCEDES_BENZ/CLK500
http://www.thepartsbin.com/guides/me...egr_valve.html
Last edited by D-MAN; Aug 25, 2012 at 02:10 PM. Reason: HYPERLINK
Thread Starter
Junior Member
Joined: May 2012
Posts: 53
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2005 CLK 500
Thx, I'll order one ASAP and let everyone now the result.
Junior Member
Joined: Aug 2012
Posts: 15
Likes: 0
2005 CLK 500
Good news, I just had the EGR replaced and it the idle is finally normal! I put about 20 miles on it in stop and go traffic and a few WOT runs. I will be putting on more miles tomorrow and keep my fingers crossed that it will remain smooth. The car seems like it is much smoother during acceleration and idles at about 500-550 RPM's. This still seems a little low to me, does anyone know the normal idle RPM's are for our cars?
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Thread Starter
Junior Member
Joined: May 2012
Posts: 53
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2005 CLK 500
Good news, I put a few hundred miles on the new EGR and the idle is still smooth, and it seems to be more responsive at various RPM's. The idle still seems low at 500 RPM's and at times will randomly raise to about 600 RPM's with a healthy deep idle sound. I am wondering if this has to do with a MAF going bad as Rodney suggested.
you mentioned your idle seems low. Mine is right in that range too, it has been since I got the car, I always thought that was normal.
MBworld Guru
Joined: Dec 2009
Posts: 10,782
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NO LONGER ACTIVE
My 5.5 idles right at 500rpm. I'd actually like it to bump up to 600 because it "lumbers" a bit and I feel it, even with new motor mounts. But it's a big V8, so I expect to feel it working. 
Thread Starter
Junior Member
Joined: May 2012
Posts: 53
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2005 CLK 500
ok so changing the EGR finally fixed my problem!!!
the car runs way smother now and like D-MAN said its definitely more responsive.
hopefully this will e the end of the rough idle from now on.
the car runs way smother now and like D-MAN said its definitely more responsive.
hopefully this will e the end of the rough idle from now on.
Junior Member
Joined: Nov 2009
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From: Brooklyn, NY
2006 clk500
Did you guys also change the tube/pipe (whatever you want to call it) when replacing the EGR, my indy said it was necessary and quoted me $160 for EGR, $100 for the tube and 2 hours of labor.
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2005 CLK 500
Sorry I have been off the grid for a while, I did not end up changing the tube. My guy said it was a lot of work to get the EGR off without damaging the tube but he was able to do it.
Junior Member
Joined: Aug 2012
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2005 CLK 500
Thread Starter
Junior Member
Joined: May 2012
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2005 CLK 500
Thread Starter
Junior Member
Joined: May 2012
Posts: 53
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2005 CLK 500
well it looks like all the work I have done last year was for nothing.
the rough idle is back with the hesitation on acceleration and the knocking is worse than ever.
not sure what I'm going to do with this car now.
the rough idle is back with the hesitation on acceleration and the knocking is worse than ever.
not sure what I'm going to do with this car now.
Member
Joined: Jan 2013
Posts: 77
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'06 clk55 : '18 Canyon Duramax: :91 325i : #33 So Cal Spec E30
So the EGR didn't fix it?
I'm having the same issue. New plugs / wires woke it up but didn't fix the idle. Cleaned the MAF, no dice. Air filters are new. I thought the EGR was closed at idle so it wouldn't be an issue. How did the part look when you pulled it out?
I'm having the same issue. New plugs / wires woke it up but didn't fix the idle. Cleaned the MAF, no dice. Air filters are new. I thought the EGR was closed at idle so it wouldn't be an issue. How did the part look when you pulled it out?
Junior Member
Joined: Jul 2009
Posts: 51
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From: San Diego
2008 CLK 550 Cabriolet
Had this issue with my 550. I had an extended warranty so I took it to the dealer. They found both engine mounts to be leaking as well as a broken transmission mount. I was also getting a code for retarded cam timing on one cylinder bank which was one of the magnetic sensors, a common problem. The "rough idle" was gone after these repairs, apparently the engine was just a little too free to hop around!
Junior Member
Joined: Jun 2014
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From: Seattle
2005 CLK 320
I had a very slight vibration at idle with no real noticable hesitation under acceleration. When my car was in getting an ATF flush the dealer also pulled the codes. They noted a misfire on cylinder 3. I had already (prior to this visit) changed all the plugs as the car was on 100k. So I changed the coilpack and spark plug cables on cylinder 3 and it was super smooth after that.
