My 15 years old with 15x,xxx miles 2000 Mercedes E430 had the code P0300 last night when we drove home on highway.
The engine seems to run smooth at speed 70-75 MPH with normal RPM around 2200-2300. When we were on surface street and at stop light the engine is rough and shake enough that I can felt it inside the car. Acceleration is hesitant and very slow, but after get up to speed of 40-45 MPH and cruising the engine was very smooth again.
The only time the engine was shaking was at idle and Idle was a little low at around 500-550 RPM instead of normal 600-650 RPM
According to engine-codes.com, possible causes:
- Faulty spark plug (s)
- Faulty ignition coil (s)
- Clogged or faulty fuel injector (s)
- Intake air leak
- Fuel injectors harness is open or shorted
- Fuel Injectors circuit poor electrical connection
- Ignition coils harness is open or shorted
- Ignition coils circuit poor electrical connection
- Insufficient cylinders compression
- Incorrect fuel pressure
http://engine-codes.com/p0300_mercedes-benz.html#ixzz3WSSGf4yS
Spark plugs(16 of them) were changed 2-3 years ago at around 130-135k miles with OE Bosch platinum plugs.
Ignition coils and wires are original.
Intake air seems to have no leak, but I don't know how to check for possible Intake air leak. Any idea how to check air leak ?
I didn't use Chevron Techron for 2 years, I usually used it every other year before smog test, but this year I forgot and just had smog test last week. May be use a large bottle to treat 20 gallon tank.
What should I do next to fix/repair the rough idle/misfired ?
TIA and happy Easter Sunday.
The engine seems to run smooth at speed 70-75 MPH with normal RPM around 2200-2300. When we were on surface street and at stop light the engine is rough and shake enough that I can felt it inside the car. Acceleration is hesitant and very slow, but after get up to speed of 40-45 MPH and cruising the engine was very smooth again.
The only time the engine was shaking was at idle and Idle was a little low at around 500-550 RPM instead of normal 600-650 RPM
According to engine-codes.com, possible causes:
- Faulty spark plug (s)
- Faulty ignition coil (s)
- Clogged or faulty fuel injector (s)
- Intake air leak
- Fuel injectors harness is open or shorted
- Fuel Injectors circuit poor electrical connection
- Ignition coils harness is open or shorted
- Ignition coils circuit poor electrical connection
- Insufficient cylinders compression
- Incorrect fuel pressure
http://engine-codes.com/p0300_mercedes-benz.html#ixzz3WSSGf4yS
Spark plugs(16 of them) were changed 2-3 years ago at around 130-135k miles with OE Bosch platinum plugs.
Ignition coils and wires are original.
Intake air seems to have no leak, but I don't know how to check for possible Intake air leak. Any idea how to check air leak ?
I didn't use Chevron Techron for 2 years, I usually used it every other year before smog test, but this year I forgot and just had smog test last week. May be use a large bottle to treat 20 gallon tank.
What should I do next to fix/repair the rough idle/misfired ?
TIA and happy Easter Sunday.