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Matt, Mechanical Engineer
Category: Mercedes
Satisfied Customers: 22903
Experience:  BEng hons Mech engineering, in auto industry 22 years
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51 C230 Kompressor coupe. Developed an intermittent starting

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51 C230 Kompressor coupe. Developed an intermittent starting problem, insert and turn key nothing happens, all instrumentation lighting come on but no engine turn, sometimes it will start straight away and sometimes it takes me a dozen turns of the key occasionally having to remove the key each time. Any ideas?
Customer: replied 2 years ago.
Could someone respond to my question please, I have been debited £20 and promised an answer wishing 10 minutes....
Thank you for getting back to me and apologies that you have not received an answer yet. We have a range of Professionals online all the time. However specialities differ, and we are searching for the right professional to assist you.
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Thank you for your patience,
Hello If the car's not cranking then first check it can turned over by hand so double checking for any mechanical issuesIf OK then check that the main battery cables are on tight and the terminals are clean and bright. Do the same for the engine / gearbox earth strap.Then follow the main positive lead back to the engine and down to the starter motor, and check the connection at this end as well.There should also be a small wire to the motor which should have 12V when you're turning the ignition switch to crank. If the 12V isn't there, check back along this wire for damage to the insulation or corroded connections This 12V feed comes directly from the ignition switch so this may be faulty and need replacing Check the resistance of the main positive lead that runs down to the motor as anything more than a few ohms and it should be replacedDon't forget to try a jump start from another car / battery as its possible the battery is poor, if you have a voltmeter a healthy battery should read 12.7+V also try substituting the battery for another as I've known a very flat battery to drag down the system voltage too far even with jump cablesone other thing to consider is that the immobiliser is faulty and preventing the starter from being enabled - however if the dash / ignition lights are on then this usually means that its offIf this is all OK then its possible the car needs a new starter motor
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Customer: replied 2 years ago.
Hi Matt, I've had the battery checked and the garage said that it was faulty so have replaced the battery, however the problem seemed to have been sorted once the new battery was installed until a couple of days later when the problem started again. Same symptoms as before, can I deduce from this that it is the alternator?How much should it cost to replace this part? Would you recommend buying a second hand one?
hello this does sound like the alternator isn't workingtypically parts are about $200-300 and its an hours labour to fit a new one and no a used one is a false economy
Matt, Mechanical Engineer
Category: Mercedes
Satisfied Customers: 22903
Experience: BEng hons Mech engineering, in auto industry 22 years
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