What is this sound?! Please see the video.
Thread Starter
Newbie
Joined: Feb 2019
Posts: 12
Likes: 0
From: Chicago, Illinois
2007 CLK550
What is this sound?! Please see the video.
It seems to be coming from the throttle body but I'm not sure. It has the same sound with the engine cover on. The car has a rough idle, the RPM needle drops and jumps back up. Sometimes it even stalls. I have cleaned the MAF sensor and the throttle body but nothing changed. The air pump seems to be working fine. Could it be a faulty MAF sensor, a vacuum leak, or an old fuel filter/pump? If not, what else could it be, and how can I diagnose and repair it?
Super Member
Joined: Oct 2015
Posts: 784
Likes: 29
From: NYC
2004 CLK 500
I just had the same issue turned out to be I had 2 bad coils . Get a good scan tool and look at the live data . Look for a coil thats misfiring. Your looking for the cylinders that looses spark for a second . I had no check engine light on mine but when I pulled up the live data you can see 2 cylinders misfiring for a split second but it wasn't enough to throw a code .
Thread Starter
Newbie
Joined: Feb 2019
Posts: 12
Likes: 0
From: Chicago, Illinois
2007 CLK550
I just had the same issue turned out to be I had 2 bad coils . Get a good scan tool and look at the live data . Look for a coil thats misfiring. Your looking for the cylinders that looses spark for a second . I had no check engine light on mine but when I pulled up the live data you can see 2 cylinders misfiring for a split second but it wasn't enough to throw a code .
Super Member
Joined: Oct 2015
Posts: 784
Likes: 29
From: NYC
2004 CLK 500
Scan soft MBII is the best for Mercedes for around $150 . Get it used and save money . Can you do this . tun the engine open the hood and take off the small front engine cover . take a long screw driver and look for plastic flap actuator on the intake . if you put the screw straight down you should be able to open the actuator . see if it goes away . If it does its the actuator inside the intake and you will need a new intake . Be careful as the engine is on . The next thing to check is the valve body . Turn on the engine and remove the engine cover and MAF . Take a mirror and look at the valve body while idling . If its moving on its own and is causing the flapping Then your valve body and or motor is going bad. You will need a new valve body . If you have a horoscope camera it will be even better . Do this before buying the scanner .
