Starting Problems-C240 Sport

[PaulHH]

I have recently joined the MB club with my first MB a lovely C240 Sport 98

Unfortuantely i have a problem every now and again which is the engine won't turn over when trying to start it. Sometimes just a delay for a few seconds before re-trying sorts it out. Both keys have the problem although one is a lot worse than the other.

Do you think this is just the key batteries requiring replacing or does it point at a more sinister issue?

 

[stevesey]

It's not key batteries, the batteries only do the central locking. Starting is powered by an induction coil in the switch.

Assume there is a click then you insert the key and then turns OK?

 

[PaulHH]

When you insert the key and turn it, you get a click but it doesn't sound like a starter motor click and the next time it starts, not always the next time but it does start.

I wondered whether the key was operating an immobiliser when it is inserted and this was not getting switched sometimes by the key.

 

[stevesey]

I was thinking of the initial click not a starter soleniod type click. Anyway if the key turns OK that shouldn't be an issue.

There isn't a separate immobliser as such, the switch (DAS) is fully electronic. When you insert the key the switch reads the code from the key if the code/sequence match the switch the key can turn and the car be started.

I'd start at the other end, starter motor contacts etc. I've not had the problem, but I recall mention of starter ring sticking (not sure it that was on the M112 engine though).

 

[stevesey]

Although you say one key is worse than the other! Odd because if the key is not recognised it won't turn (I think - I have a duff key I'll check that)

Still might be worth cleaning the window in the end of the key (and the switch).

 

[PaulHH]

I'll try cleaning the key and the wee window bit. With the key turning though I guess as you said that the key is probably good. I'll get the starter checked out and move backwards from there.

Cheers for that.