Coolant loss and misfire......possible head gasket?
 

2002 e320 need some help figuring out my problem. My cars coolant light comes on every few days and I have to add coolant to it. The first time of the day that I start the car it puffs white smoke for a few seconds then clears up. I pressure tested it and it shows no sign of leak. I'm also having a cylinder 1 misfire issue in that I have replaced the plugs, wires coil and fuel injector for that cylinder. Still occasionally get the misfire code. My question is could I have a problem with my head gasket on the number 1 cylinder side causing both these issues, the loss of coolant it being burned out the exhaust and is it possible a bad head gasket could cause my misfire issue? I'm stumped all help is appreciated.

When you say pressure check do you mean the coolant system? If so I would suggest a compression check to see how number 1 compares with the other cylinders.
Also check for any signs of oil floating in the coolant tank and check for water in your oil as indicated by brown muck under the oil fill cap