Why won’t my 2005 C230 Mercedes start?

Hey guys! The car will crank, starter will turn but it just won't run. Here's what I've done to it to try and remedy it: changed crankshaft sensor, checked both fuel pumps and fuel pump relay, checked all fuses, gas tank is half full, battery is good, oil level is good, all spark plugs changed. Been scanning for codes; none returned... I need help. Thanks!

3 Answers

  • Anonymous
    1 year ago
    Favorite Answer

    Replace air filter and try to start.  No start, listen to the engine noise while cranking.  If engine sounds like a blender, check for a broken timing belt/chain.  Check vacuum if you are not sure with a vacuum gauge while cranking.  Vacuum should be from 17 to 22 inches Hg.  If vacuum is low, check timing belt.  Vacuum is high, check for a stuck closed throttle body or a bad idle air control valve.

    Engine sounds normal, try to start and check if security light is flashing.  Light is flashing, there is a security issue.  Light stays off,  spray starting fluid on the intake or vacuum line and try to start. 

    Engine starts and dies, check fuel pressure with a gauge while cranking.  Fuel pressure is good, check if the injectors are firing and getting command to fire with a noid light while cranking.  Fuel pressure is bad, check if fuel pump is getting power and ground while cranking.

    Engine does not start, check for spark while cranking with a spark meter.  No spark, check for 12V at one of the power feed to a coil while cranking.  Power feed is good, you will need to check current ramp with an o-scope.  PCM could be bad.  Power feed is not good, there is an electrical issue or an injector could be shorted.  If ignition fuse is blown, check for a shorted injector.

    Spark is good, check for a bad idle air control valve or a stuck closed throttle body.

  • 2 months ago

    REMOVE the SPARK PLUGS and have a friend put his hands near the vacant holes to see if AIR is getting pushed around! You MAY have a busted HEAD GASKET< and that is a CINCH to change yourself with HAND TOOLS and a fresh gasket set! You MAY as well have your HEAD fully cleaned at a machine shop as well! Is this a KOMPRESSOR engine?? IN THE FUTURE>>use ONLY PENNZOIL ULTRA EURO OIL and DENSO TWIN TIP IRIDIUM LASER PLUGS! And ONLY GENUINE BENZ COOLANT and NOTHING ELSE! USING DENSO TT plugs will get you up to 20% MORE POWER and MILEAGE as well 

  • 1 year ago

    you need to have a mechanic check it out

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