HELP MY CL55 AMG SUPERCHARGER 2003 HAS A VERY UNEVEN IDLE WHEN IN GEAR OR NOT . WHEN HOT OR COLD THE SPARK PLUGS AND LEADS HAVE BEEN CHANGED CRANKS SENSOR NEW AND NO FAULTS FOUND MAF SENSOR CHANGED AS WELL .MERCEDES HAVE HAD CAR FOR TWO WEEKS AND HAVE NOT FIXED IT YET THAY HAVE NOW EVEN REMOVED THE SUPERCHARGER AND INLET MANIFOLD TO CHECK FOR AIR LEAKS AND FOUND NONE CAN ANY ONE HELP THANKS GUYS


PS MERCEDES UK ARE NOW GOING TO SEND THERE TOP MECH DOWN TO LOOK AT THE CAR SOON

Have they identified a problem cylinder(s), or is it just random? Have they checked for fuel contamination? Does it have a collapsed engine mount? If all that stuffs' been found to be OK, I'd check cylinder compression/leakdown. It doesn't take much time, and can tell you a lot. If no problems are found, I'd pull the fuel rail and check for a pi**ing injector. I feel stupid recommending these steps, since I'm sure they've already been checked, but you never know.

HI THAY TELL ME NO 8 4 5 CYLS HAVE A MISFIRE BUT NOT ALL THE TIME .THE COMPRESSION TEST WAS OK MORE UNEVEN WHEN COLD AND STUTTERS WHEN U GO TO PULL AWAY WHEN COLD NOT AS BAD AT ALL WHEN HOT

If it were me, I'd check for fuel contamination before I did anything else. Due to the shape of the fuel rail, contaminants, e.g. water, usually affect the left bank of cylinders(5-8). If any contaminated fuel makes it to the other side of the fuel rail, the #4 injector is the first place it ends up.

As far as the cold engine performance problem, I had an E55 AMG in the shop a while back with a similar problem. After starting the engine first thing in the morning, it would miss badly under heavy load. After it warmed up a bit everything was fine. We took a fuel sample and immediately noticed that it looked very cloudy. After the sample sat for about a half hour it started to separate into two distinct layers. To this day I have no idea what it was(it wasn't water), but when we got fresh fuel into it, the problem went away.

The point of the story is, check the easy stuff first!

thanks for that how can i get all the fuel out of the rails .just to let u know that mercedes has had the supercharger off and the inlet manifold to check for air leaks but found none thanks