buzzing sound wont start

[zubat6]

hi can anyone give me advice
i have a 1990 230e auto when i put key in the ignition and turn to position 1, there is an electrical buzzing sound, the engine will not turn over or start, i have changed the relay and also fully charged the battery but still not working, and i have to jump start before i can drive, so my rev counter and petrol gages are not working, but speedo ect are, anyone have any ideas what it could be
thanks

 

[BoyracerAU]

Is the buzzing sound simply the fuel pump?

And does the engine attempt to turn over at all, even just very very slowly?

 

[zubat6]

when i jump start via starter motor to battery i can drive, but does not turn over by key only starts by jump start, dont think it fuel pump
thank zubat6

 

[horgantrevor]

check wire to starter motor and earth strap

 

[zubat6]

Thank you
any other ideas would be good
zubat6

 

[AMGBlack]

The buzzing could be the starter soleniod, which is sticking. The extra "oomph" from a jump start at 14.5 volts could be enough to engage the soleniod and thus the starter motor starts. (Sticking).

Well, it was worth mentioning as it has happened to me several times in the past.

Cheers and good luck.

 

[Mercsys]

If the 2X battery starting sounds rough the starter is shot, could be grounding. If so the double battery fix won’t work for long.
Else, Take a look at the cranking voltage, should be 6-9volts, if less look at the battery.

 

[Danny DeVito]

when i jump start via starter motor to battery i can drive, but does not turn over by key only starts by jump start, dont think it fuel pump
thank zubat6

Sounds more like jumping from the cars own battery. If thats right then either the solenoid is faulty or it's not getting power. Maybe a test lamp would be the easiest to check it ? And where is the buzzing noise from inside or the engine area ?

 

[zubat6]

the buzzing is coming form the engine area ner the fuss box i think the buzzing coming from the relay so i change the relay but still buzzing

 

[Mercsys]

Are your head lights good with the engine off, if they are almost as good as when running, battery is probably good, else battery is suspect.
what happens to the cabin lights when you crank with 1x battery, if they dim significantly, suspect the battery and earth straps, if not, look at the starting side only.

 

[Superspec]

When you say buzzing, it's not like an electrical arcing sound is it?

 

[zubat6]

yes it is a electrical sound, sound is lower when indicator and headlights are on, sound is near driver side fuse box and relay box have checked and changed both

 

[Danny DeVito]

Is that petrol or diesel ?
Take out the relay you suspect, does the noise stop ?
On ur starter you will see the heavy battery wire and on the starter solenoid u will see a small wire to energise the solenoid. Remove the wire to the solenoid (probably a spade connector ) Attach a wire from battery + and touch of the spade connector on the solenoid. Tell us then if the engine turns over please. I wonder why the gauges don't work ? It sounds like something more than just the starter problem.