HELP Please

[S54addict]

what an amaizing day for a drive! Well, until I stopped for a sneaky 1/2.... Jumped back in the Z4M flicked the key only to hear a click tried again a short turn over maybe once but not enough to fire repeatedly tried about 10-15 times and a mixture of clicks or tries then just I was giving up hope she turns over and fires up as if nothing had happened??? When I got home I turned her off and checked the battery terminals ( as I disconnect over the winter ) seem fine tried starting and basically a repeat of earlier, again resulting in a start as if nothing was wrong.
Is this the start of the starter motor failing, or solenoid, or possibly ignition switch??
Any help appreciated

 

[DavidM]

Can't help you unfortunately - an auto electrician may be able to diagnose the fault fairly quickly.

 

[BMBabe]

@t-tony @Brian H

 

[t-tony]

My initial reaction to that would be check the connections on the starter motor itself, the large battery cable and the small exciter wire. The small wire is fed a 12v live to pull in the solenoid on the starter motor which in turns makes the connection of the main battery cable to turn the engine over. IF, it happens again and if it's possible try to "tap" the solenoid on the starter motor while someone turns the ignition key to the "start" position. Most likely it's the starter motor at fault.

Tony.

 

[Stevo7682]

I would have to agree with tony from what you say sounds like starter.

 

[hard top]

or possibly ignition switch??

Also very possible, had that happen on a Merc.

 

[t-tony]

Unusual for a faulty ignition switch to fail and then work again. Not impossible but unlikely as the contact soon overheat and become useless.

Tony.

 

[Stevo7682]

@S54addict where abouts are you. Maybe your located near enough to one of the more mechanically minded members to take a once over for you

 

[oldcarman]

Also very possible, had that happen on a Merc.

Me also in my Merc but I'd put money on the starter motor. JIM

 

[S54addict]

My initial reaction to that would be check the connections on the starter motor itself, the large battery cable and the small exciter wire. The small wire is fed a 12v live to pull in the solenoid on the starter motor which in turns makes the connection of the main battery cable to turn the engine over. IF, it happens again and if it's possible try to "tap" the solenoid on the starter motor while someone turns the ignition key to the "start" position. Most likely it's the starter motor at fault.

Tony.

Yes, I have done a little research on forums and this is quite a common problem apparently with the S54, As you quite rightly say, it could be a dirty patch on the starter motor to which a tap with a hammer or rocking the car can get you going, also an ignition switch but like you say, it either works or it doesn't, not really an intermittent fault, clutch sensor?? Or even a faulty key transponder.
Loose or dirty earth... I am looking today so will hopefully may well un earth something...... That was a slight attempt of humour

 

[hard top]

also an ignition switch but like you say, it either works or it doesn't

Mine on the Merc was intermittent until it stopped working all together when I was parked outside a bar at one in the morning.
Phoned my mate for a tow home (who had also had a few) who took me down the road at warp speed, me with no brakes or power steering, swerving around all over the place behind him.
We passed two police cars on the way going in the other direction who did not even look at us........

Oh, the naughty days were great....

 

[Redline]

I'd suspect the starter - the fact that you can hear solenoids closing would indicate that the ignition switch is supplying a call to power when needed. It could be the solenoid in the starter itself as Tony suggested. The contacts on this solenoid are taking an awful lot of current so can easily burn out. If that is operating OK its a starter problem itself.
I have had other sensors cause problems before on older cars. If its a sensor fault i would expect a code to show up on the ECU.

 

[Ianmc]

Could simply be a knackered battery?

 

[Antm72]

Sounds to me like a lazy starter .As long as the battery is good not much else it can usually be.
Have you tried testing the battery whilst you crank it does it dim off all the dash lights ?

 

[S54addict]

Lunchtime drive... Started first flick of the key stopped bravely for Sunday lunch and a beer..... Started 1st flick appear toy if you turn the car off and and the starter has stopped on a dirty part of the motor? It needs to move off of it to start that is why you can start it after rocking it. Basically the starter motor is F&@!/D

 

[t-tony]

Certainly looking that way.

Tony.