1999 5 series non starter

[Emerald11]

Hi guys... I need some help. 

I have a 99 520i touring petrol automatic. 

There's an intermittent problem. Sometimes starts and drives perfect, other times light show on dash but doesn't crank or make a noise. 

Only have one key also. Any suggestions of how to get it started? Thanks. Jay

[Greydog]

Morning Jay

Welcome to the Forum

Your issue could be several things I am afraid 

First the simple things try putting it in N to see if it starts that would point to the Inhibitor on the gear selector.It could be the ignition switch (not as hard to change as some think) 

It could be an intermittent fuel pump or power relay. A diagnostic session would help

Hope this is helps more than hinders

Dave

[Emerald11]

Many thanks. Will look into this. Thanks! 

[X5smw]

This was happening to my x5 and I changed all the ignition barrels and dme units etc…. Turns out it was the immobiliser chip in the key. 
 

I bought a key programmer and a blank key with chip off Amazon and got a new one cut for less than £30. 
I would see if you can borrow someone’s diagnostic software and put the live dme screen on. Put the key close to the ignition and see if the chip reads constantly. 

[Emerald11]

Thanks x5smw

 

Update.. Looks like it's the immobilizer.. So will hopefully be able to bypass it.