Hello to all,

I am new to the forum because my mercedes 300E keep giving me a terrible symtom that I can not solve.

Problem:

Whenever I start the engine, it always require me to start two times. The first crank will not start the engine.

After the engine started, the engine once in a while shaking like crazy. Most of the time, quiet and smooth.

In highway, the car runs very smooth. However, in local, stop and go, the engine shakes and almost dies out.

Here are few things that I've replaced.
1) Spark Plug Wires
2) Spark Plug
3) CAP/ROTOR
4) Oxygen Sensor


Lately, I discover that I heard muffler noise .. like clogging with loud noise. I am wondering if there is something wrong inside the muffler or not. Whether a piece of ceramic or something inside. I am totally confuse. Don't know what to fix. Please help.

Again, engine takes two time to start. Run rough in local, but smooth in high speed.

Thank you and hope to hear some feedback.

 

not easy to diagnose it by just online.

must be done by experienced mechanic.

it fuel/air problem which involves a lot of things.

pressure
electrical
adjustments
sensors
etc.