Not kit related at all, but something someone might be able to help with i hope!

I have a e46 330ci, owned it for 2.5years now and had to replace the fuel level sensor FIVE times now!!
Every time it has been the same problem, the little circuit board cracks in half.

heres an image to show the bit that keeps cracking (this isnt cracked, but i dont have a photo of mine)



If this had happened once then ok... but 5 times?! theres obviously something causing this.

Its run on shell fuel 90% of the time (its petrol not diesel)
I do about 20k miles a year
It sits for 2weeks at a time out of 5 weeks (i tend to find it happens after its been sat?)
Theres a rubber seal between the sensor and tank so i guess this stops vibration to a degree

can anyone tell me whats going wrong?

Or, does anyone know of an epoxy that I can smear all over the back of it to strengthen it that wont react with the petrol?

[Edited on 24/8/14 by Matt21]

Rover more or less the same sensor, two sensors one each side of the tank with no issues.

Are you sure it is A - the right sensor? And B - is it actually fuel that is cracking it?

I have seen them crack through a spike in voltage down the supply line - that's if it's a voltage based signal that's produced by the sensor?

quote:

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Originally posted by jwhatley
Are you sure it is A - the right sensor? And B - is it actually fuel that is cracking it?

I have seen them crack through a spike in voltage down the supply line - that's if it's a voltage based signal that's produced by the sensor?

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im not sure whats causing it, thats what im trying to find out

yes its resistance based.

as for the right sensor, im guessing you mean 'am i replacing it with the correct part', yup, 100% genuine bmw parts for my make and model

The damaged part doesnt look to have been corroded etc, its just a clean break as though its been snapped. But there isnt anything to snap it? certainly without snapping the whole of the bottom of the unit off.

There are two level sensors, one each side of the 'saddle shaped' tank, one is just a level sensor (the one thats causing issues) and the other has a pump aswell as level to pump from one side of the tank to the other.
Theres a trick you can do with the dash that displays what each sensor is reading, ones saying 000 (0litres) the other gives a reading of 028 for example (28 litres i believe). this shows that the 000 one is goosed.

its very bizarre

[Edited on 25/8/14 by Matt21]

Is the float arm able to move sideways ?

It might be on corners the fuel sloshes across moving the arm into the board.

could be a good call, i'll have a look when the new one arrives
though im not sure theres enough weight/profile to it to cause and issues, but il check it anyway