Battery light on my 318 is constently on, but starting ok

[dmc2884]

The battery light on my 2000 318i is staying on but the car has been starting fine for a week now, also when i start the car the yellow oil light comes on for 15 seconds then goes off again...

can anyone help

thanks Daniel

[sniff diesel]

Can you get a voltage reading from the battery with the engine off and another with it running?

I'm guessing your alternator could be on it's way out.

[GreenV8S]

I'd expect the oil pressure warning light to come on when you switch the ignition on. It would normally go out within a few seconds of starting the engine. If it's staying on for fifteen seconds or so with the engine running that could be a sign that you have a very worn oil pump.

'No charge' warning light usually means that the battery isn't being charged. If so, the battery will gradually go flat. Using the starter motor, and using headlights, would speed this up considerably. There are some other faults that would cause the no charge light to stay on but most of them eventually result in a dead battery.

If you leave the problem it's very easy to damage the battery which adds a significant expense.

[phelix]

yellow oil light might be the level rather than the pressure - when did you last check it?

[gmarks1]

Had the battery warning light flickering on and off on my car recently (E46 330Ci) - eventually the battery completely discharged (luckily I was at home in the drive when the car shuddered to a halt) Problem was a faulty alternator (unfortunately quite expensive) The car was starting and running perfectly before - if this is the fault, be careful or you may be left stranded.

Yellow warning light on start-up is either low oil level, or a fault level sensor (they are prone to failure)

Gary

Edited by gmarks1 on Saturday 1st November 14:37

[sniff diesel]

I'd start looking for a second hand alternator if I was you.

[dmc2884]

my oil level is still on maximum, i was told it could be the oil pressure switch

[GreenV8S]

dmc2884 said:

my oil level is still on maximum, i was told it could be the oil pressure switch

They would both normally come on with the ignition and go off when you start the engine so it isn't always obvious which is which. You can tell what the light is by seeing what it does if you rev the engine and then switch off.

The no-charge warning light will usually come on the moment you switch the ignition off, stay on as the engine spins down and then gently fade out as the engine slows to a stop. The oil pressure light will stay out the whole time.

[roofer]

Have you checked the belt? Is it a seperate one on them? If the light glows when revved, you may have a blown rectifier in the alternator.