Oil presure light on start up, then goes away.E90 320i. Please help.

[Sporti2]

Hi,Please Help! Assistance would be much appreciated.

My oil pressure light comes on at start-up then goes away. There is a noise to confirm that the pressure is low for about 3 seconds. This does not occur on initial start up in mornings and when the car is hot.

What we can rule out:
1. Yes I've checked the oil level. In fact I've completed 2 oil services in the past 3 days.
2. We have removed the sump yesterday and noted that the pickup filter was broken. We cleaned out the sump and all we could and replaced the pickup filter. No trace of any sludge was found.

3. Now what...? please help. Thank you

Please see video link below. (the clip just ends before the light goes away)

 

[Charlie Brown]

Faulty sensor perhaps, common on the E46 not too sure on the E90s though.

 

[Maljan]

Could be a faulty oil level sensor.

 

[Kish2604]

Only 3 things come to mind,

The first one being the cheapest of the 3 and that is the oil pressure sensor, the second being that the engine is sludging in the oil channels like cholesterol inside your block,did you get the valve cover off? the third would be a third oil pump is getting lazy and needs a revive...

 

[Sporti2]

Hi guys, Thanks for the feedback.

1. I don’t think it can be a sensor because I can actually hear the car lacking oil pressure on start-up. It sounds like a tractor for 2 -3seconds.

2. I also don’t think it could be sludge, we flushed the system and cleaned out the sump, and also noted before the clean up that there was no trace of any sludge.

I think I’m left with the most expensive option, the oil pump. Would it be ok to fit a second-hand one?

 

[Tiehjohn]

Check the oil cooler. Might be full of dirt