Hi,
I recently took delivery of this car (2006 CLS55 AMG) and the CEL was on. I used a pretty basic OBDII scanner to read the codes. It was throwing P0505, P0507, and P0106.
After driving for about 20 minutes the engine was shaking, and did not feel like it was running well. The transmission seemed to be shifting awkwardly. This was happening at low RPMs and at about parking lot speed (5-7 mph).
Read about possible vacuum leaks caused by loose hoses, thought this was probable because VC gaskets were done recently. I removed the air box and driver side surge tank cover to get better access. Could not find a loose hose / cracked vacuum line in that area. I also noticed that the TB was fairly dirty, so I gave it a quick clean.
I put the car back together and started it up. The CEL was still on, but code P0106 was gone. I still had P0505 and P0507
Tried to clear the codes using OBDII scanner, and I was not able to. (possibly because the scanner is cheap / not meant for MB cars?)

Any help would be appreciated because I'm not super sure what to do

Thanks!

 

P0505 / P0507 are usually vacuum related. Check all all the breather hoses for any cracks. If you're unsure how to check, I would take it somewhere to get a smoke test done and it'll show you any vacuum leaks.

 

I was able to perform a smoke test and it did seem to reveal a leak on the driver side, but I can't seem to find the hose. There was smoke coming out from somewhere by the location of the valve, but I could not see down there. Is there a way to see these hoses without removing the coil packs and / or valve covers?

 

Pull off the air boxes and the from the drivers side looking at the engine, the upper right valve cover bolt, meaning closest to center firewall, also holds down a rigid tube that goes into the back of the supercharger and is the most often cause of issue after a valve cover gasket job. Follow that and you will find what you are looking for. All other hoses up there plug into the valve cover breathers. Anything close to the throttle body needs the surge tanks removed.

 

I ran another smoke test, but this time there was no smoke coming from any hoses, I found that smoke was coming out of an opening in the air box where a clamp is placed, but no hose leaks. (at least according to the smoke test). Went for a drive and the CEL came back throwing codes P0505, P0507, and P0455. P0455 is a new code. Also I am getting a warning that I need to check the gas cap.

also: at lower speeds (5-7) and RPMs it is running noticeably rough and it is not shifting smoothly. It seems that it runs worse only when the CEL is on, when it is off it runs pretty well, idle is a little rough. This may be a stupid question, but does the CEL being on change how the engine and transmission run and their operating smoothness?



I'm at a loss on this one
Any ideas?