Is my ignition (starter) switch faulty?

[pete&gill]

Hi all
My Cali is coming up to 5 years old - 2008 174 Tiptronic
Some times when I turn the key nothing happens, but turn it back and try again and the engine starts - no problem I thought.
Lately however this seems to be worsening and this weekend it took around 5 times on one occasion which was a little worrying.
Has anyone had a similar experience? Have I got a serious fault developing or am I missing something obvious?
Any feedback much appreciated.
Pete Woods

 

[calikev]

Re: Is my ignition switch faulty?

Sounds like it could be the starter motor pete I'm sure I read somewhere on here of a similar problem. Found it this should help viewtopic.php?f=20&t=2373&p=21109&hilit=Starter+motor#p21109

 

[Freeley]

Re: Is my ignition switch faulty?

If the lights on the dash come on when you turn the ignition on and you hear an audible "click" when you try to start it then it's probably a faulty starter motor.
I had mine replaced at 2 years old and i know of at least one other on here who had the same.
If the ignition lights don't come on then i've no idea i'm afraid.

Beat me to it Kev!

 

[John]

Pete,

Intermittent faults are always the worst to work on.

If you have a voltmeter put it across the starter battery it should show around 12.5 V for a healthy battery. Old battery's that don't hold their charge or that have a high internal resistance can be a cause of starting problems. This is a problem that is especially common in the winter.

Check your Cali is not in gear and the handbrake is on.

Now get someone to turn the ignition switch to the starting position. When you have the fault (i.e. the engine is not turning over) does the starter solenoid click and does the voltage drop.

Another way of checking for the voltage drop, if you do not have a voltmeter, is to put your headlights on and check if they go dim.

If you get a voltage drop and the solenoid clicks but the starter does not turn over it is most likely the starter motor at fault, its wiring, or connections.

If you get a voltage drop with no click it is most likely the starter solenoid or connections.

If you don't get a voltage drop the fault is in the starter circuit. In this case it could be various things like the ignition switch, the immobilizer, the engine ECU, a loose damp or faulty plug or bad wiring in the circuit.

Finally bad earth connections can also cause starter faults so check the condition of the earth connection to the starter battery and the earth connection to the engine. Check for corrosion and if necessary use a wire brush then petroleum jelly (Vaseline) to clean and grease the connections.

Hope this helps.

John