C180 Is A Sudden Non Starter

[Beachster]

Ok this is my first post since joining, so, Hi ! But as with most first posts it is because I need help and you guys are my only hope.....

...Well apart from a local garage and a ton of cash..

Ok here's the problem. My Wifes (52 plate C180 2.0 no Komp) stopped starting. All was fine no problems until last Saturday, she went to the shop, parked up, shopped, got back in and....nothing!

I rushed to her rescue and after a little head scratching and key turning decided to go for the highly technical bump start method and it fired up.

Got home, parked up, and now nothing!

Symptoms:

• Turn key to positions 1 and 2 and dashboard lights up, a few relays click under the bonnet, a high voltage kinda whine comes from around the spark plug area.
• Turn key to position 3 and silence... all the above is still there but engine don't turn, does not even try.

I have read and trawled this forum....nice work by the way...admirable love for your cars...anyway, so I thought battery, easy. No, measured batt and 12.5 Volts, bump started again and Alt is pumping out 14.5V. Checked fuses...all the ones I could find are still good.
Assumed that if it starts with the slightest of pushes then the leccy ignition system all good.

Thought it was immob but I can get in and out no probs and after reading some of the recipes for re-synching the key (and trying them) I have now discounted that (besides it starts and drives perfectly as long as you dont mind asking people for a push start)

So I am now turning to you pro-am's for some good advice. I am not good at taking engines bits apart but I am leaning rather heavily towards starter motor....and need a vote of confidence I am in the right area.

 

[al8565]

welcome. I'm no expert, but could it be starter motor?

 

[dale]

ok ok .... i may way off the mark here, but my MK1 fiesta does this. quick hit of the starter motor with a spanner/bar and we're away. something to do with a sticky solenoid.

like i said though.. thats a 30 year old fiesta and i'm not clued up on mercedes but may be worth a shot does sound like a starter motor issue.

 

[Shude]

My car did exactly the same thing and it turned out to be the starter-motor cable which had simply snapped! Replacement wasn't that simple though

 

[renault12ts]

Check the earth.

BTW I wonder who holds the current record for length of membership before first post.

 

[rpe2]

A link to a useful post on another forum..

http://forums.mercedesclub.org.uk/showthread.php?t=46827

 

[renault12ts]

A link to a useful post on another forum..

Where?

 

[Beachster]

Thanks Everyone for your responses (post count now = 2! I'll take that record if its up for grabs!)

So tonight I'll Jack it up and...

1. Hit Starter Motor with a hammer.
2. Check Earth.
3. Check for wire attachment and breakage.
4. Report back.

Any one know how much a starter motor costs ???

 

[CLK 320 AMG]

Similar recent problem with my clk and it turned out to be the Earth Strap had broken.

 

[BlackC55]

Are you sure you checked ALL the fuses?

 

[lynall]

Had same on a disco years ago and all cables were fine but one was corroded between the cable lug and the bodywork but looked fine visually, so worth removing cleaning and refitting.


Lynall

 

[recycled]

check your battery terminals clamps. Mine snapped in two but stayed on the battery so looking at it i thought was ok.

 

[j.mannion3@ntlw]

Have been having the same problem with my 51 plate c220 cdi.
A 15 amp fuse has blown twice in the last 4 weeks.
It is located in the fuse box under the bonnet in front of the steering wheel, looking from the front of the car it is the 15 A fuse on the left hand side of the row of fuses. It is slightly awkward to get at as it is immediately below the wiper mechanism.

Hope this helps

John.

 

[Beachster]

Just wanted to thank every one who replied and helped me out.
Just to give you update on the result:

And I recommend this diagnostic flow for all MBs with this problem (as it seems quite common ):

1. Assume that, as you can get into and bump start your car and it runs, immob is ok!
2. Start with the fuses and check them all (come to MBClub if you do not know where they all are) - mine all ok.
3. Check Your battery voltage (you will need a multimeter of some sort) - mine 12.5 V so good.
4. If you can bump start the car then check the voltage again when running you should see increase as alternator is now recharging your battery - mine 14.5 V so good.
5. Now you are left with wiring and starter motor - bit tricky now (Thanks to rpe2 for link to other forum thread) you can check (again with a multimeter) that voltages are flowing around your plugs and the relays are transferring across to other wires (you only really need to check two the feed to the starter motor - well I only checked two) see rpe2 link. With help from some one turning they key on and off. - mine good.
6. If you can get to the starter motor then you can continuity check the wires - if you know where they all go - I checked the direct feed from the plug in the fuse box - short - so good. Then checked earth to earth (car chassis) - short so good.
7. Ergo - starter motor knacked!

I'm no good taking bits off cars so got garage man to do it - £277 (£153 for new motor the rest labour and the taxmans) - I know, I know, I checked later and found one on euro parts for £90 and could of got it fitted for less!!

By the way I am not an auto electrician just an electrical engineer I don't know if the above is the correct way or if the readings are right. It seemed to help me so I thought I would share my exciting experience with others.

Thanks again!

 

[rag1873]

Thanks for that Beachster, ive got the same problem with my C200 and didnt know where to start. The battery etc seems ok but i dont have a clue when it comes to testing starter motors and other wires etc!!