[lsdlsd]

Dear all,

If anyone has experienced and yet found a solution for this issue please advise!

I just bought a pre-owned MB C-Class W203 Petrol Engine (M271.946 - 1.8L Kompressor). The car has 90K KM and I'm experiencing a nightmare with low rpm performance when braking on red light traffic stop / parking the car either on R and D automatic transmission position. Also "Check Engine light" is ON.

In order to find out the issue, just did a SDS Scan and the problem seemed to be "Fuel mixture too rich". Also there was oil leaking in the rear vacuum pump which was repaired, checked vacuum hoses for vacuum leak but nothing came out to cause this issue.
In addition to the above described issues also the front magnetic CAM sensors have oil leaking.

Please advise possible solutions to fix this issue!

Thank you in advance!
LSD

[oblivion202]

Does it feel like engine is running lumpy, there is a vacuum pipe under the airfilter which splits and causes engine to run a weak fuel mixture and brings up fault engine running at rich stop were the ecu detects the engine is running weak and tries to richen the fuel mixture to the max the ecu can goto. Also if you can read live data and see what your airmass is reading and your o2 sensors, the cam magnets are also a common problem mercedes have i think modified them and the electrical connection. hope this helps.

[vehicle.top]

Air mass sensor fault.

[lsdlsd]

Hello Guys and thanks for the suggestions.

During these days I've been spending more and more time trying to figure it out what is causing the problem. To cut I short, I've rechecked every single air connection for possible leaks; tested with different throttle body; tested with different MAF sensor; tested with different cam magnets; replaced the torque converter; replaced engine mountings; checked alternator pulley and after last intervention where I replaced engine mountings the vibration is stabilized but the RPM Fluctuation still exists.

In the attached file (in my first post) you can find the link of a video I uploaded last night in order to give an exact picture of the issue. Mercedes Diagnose 'DAS' doesn't give any error related to the symptom and this happens usually on low speeds.

Please advise.

Many thanks!

[benzcoupe]

You can raise the idle speed in the ecu menu either while in gear or in park or neutral.. sometimes that will help alot.. ive had to max them out before... these engines had leaking valves with showed up more at low rpms... also these engines were VERY unforgiving of lack of oil changes.. the way i tell if the oil has been abused is i unscrew oil cap and look at the bottom of it if it looks even slightly cooked the engine has had at least one neglected oil service... i cannot tell you how many mysterious misfire and oil consumption problems i have fixed simply by doing a special crankcase flush procedure that i have developed for ANY engine really... with MB the way to tell if u REALLLY got sludge issue is... add 2 qts to already full crankcase... or drain 3 qts and start engine if it doesnt say engine oil too high or too low withini 5 min (max) the level sensor is stuck ... from sludge plain n simple.. that means the oil return slots in the pistons are clogged.. alllowing oil into combustion chamber which is HIDDEN by the cat converter...MB cats are expensive for a reason.. they reach full operating temp with 3o secs MAX..if the plugs are black but kinda dry .. there is your misfire problem..all caused by not changing the oil bottom line

[gera64]

Hello
you must first observe the hose and engine vent valve of the engine crankcase to the intake manifold (take out multiple)
then you should verify that when the lambda regulation starts the values ​​of zonda are in values ​​of between 1500 mv ,, if you go to 2800 mv the zonda is in short
and always control the throttle air / throttle valve at pressure of the compressor (on motor support)
sure will succeed