oil pressure light

[tomo]

working on my cousins 2002 x5 3.0d turbo his batterys been flat for about a month, i took it into work replaced the battery and then on the journey home when i stopped the oi pressure warning came up with the oil light, i stopped checked the oil level which was on max, started driving again fine untill i stop and light comes on again, so it seems the light only comes on at low revs, anyone else had this problem? and it is more likely that its the oil breather blocked (oil style) and needs changing, or the oil pressure sensor? or am i in completly the wrong direction?

[X5Sport]

What engine speed is it idling at?

Blocked breather usually causes an increase in pressure - and potentially turbo failure if ignored - rather than a decrease.

The pressure and level sensors are known to be problematic.  I had mine replaced when the car was less than a month old!!  If the idle revs are OK, then it might be the sensor.  The only other thing I can think of is that because it's standing idle, the oil may be 'old' and some galleries are clogging as the crud settles out, or possibly a blocked filter cartridge?  Perhaps an oil & filter change might help?

After that it gets more complicated with the pump maybe needing looking at.

Richard

[tomo]

cheers ill try an oil and filter change first and a flush , then have a look at pressure sensor, suppose i may aswell go for the breather aswell as it can only help if it hasnt been done before

[X5Sport]

You'll find a lot of the tech instructions in this thread on the Forum.  Breather change always a good idea - and been done by a fair few of us.