Red oil light flickering on idle e46 B3s

[hap]

Hi not driven for a while but went for blast but when pulling up to light or T junction red oil pressure light coming on flickering still on when in drive and foot on brake…put into neutral disappears and goes out when starting driving away
Car drives fine sure oil level ok but will check
Any one had this on a b3 or generic E46 pls ?
Thanks

[davettf2]

Hi Hap, I've not had this with mine, or at least not noticed it. I assume that in 'D' with the brake on the RPM is dropping, could it be dropping just a little too low?

Cheers
Dave

[Charles]

This suggests low oil pressure - experienced this when my engine was rebuilt recently with a new oil pump. Eventually cleared and was clearly related to low revs.

If in drive on the brake, the revs drop slightly which reduces the oil pump pressure. Sitting in neutral brings revs up slightly along with the pressure.

You say that oil level is ok but how full is it?

[hap]

Thanks both I’ve not noticed any difference coming to a halt in terms of revs dropping seems normal behaviour
Checked oil level few weeks back was ok normal in between min and max will check it again tomorrow if chance
So possible dicky sensor or actual pump then Charles
Pretty concerned

[Yad3100]

Yep low oil pressure at idle will cause this. I have seen it once with the M3 when it was on the low mark and the focus used to do it after track sessions until I changed to an ester based oil as it deals with heat better (doesn’t thin so much).

Potential issues
Low oil level
Faulty sensor
Thin oil, either wrong weight or has been diluted by fuel, through time it’s been in there or the car running rich. If it’s been diluted you will smell the fuel from the oil.
Some oils can suffer with condensation in the block in cold weather especially if doing short trips, which can also create emulsion to form. Usually this doesn’t effect the pressure as the pick up is deep in the sump pan.

As Charles says there is a pressure release valve on the pump and this can start to fail and bleed pressure. I had a high pressure one fail shut and it blew the crimp on the filter, what a mess that was.

It sounds like it’s not an engine fault as you would also get some noise if it were the bearings that were damaged and the light would stay on so don’t jump to dramatic conclusions. Hopefully just something simple.

[Hodge]

Hi Hap

I had the same symptoms with the light flickering, turned out to be just the sensor as a recall, so thankfully the easiest of the issues.

HTH

[hap]

Hi mark hope your keeping well after reading a few bits on internet that was the common resolution so fingers crossed I presume it’s the original. I wasn’t aware it was in a recall? Or do you mean you recall
I will check oil as matter of course and get it checked in new year
Cheers

[Hodge]

Haha yes, I meant “as I recall”. Well spotted though

[hap]

Check level seems ok but the whole brown dip section looked wet but it’s not overfilled

[Charles]

If the oil level is good then it is likely to be the oil pump not generating adequate pressure at tickover.

If it is just flickering and disappears once running, then I wouldn't worry too much. As you have found, by putting the car in neutral(or Park) at standstill, this takes a load off the engine and the light goes away. If you hold it in Drive then there is enough load to draw down the revs very slightly which causes the sensor to identify low pressure.

I had this immediately after my engine rebuild with a new pump and after a few weeks it stopped doing it. Why? - I haven't a clue but it stopped and everything is fine. I would monitor it and give the car some good long runs to get the oil nice and hot and under pressure to see if there is something that has clogged the spring in the pressure release mechanism in the pump.

[hap]

Thanks Charles,Adam so followed your advice
Ok so drove a mile after several days since last update,I let car idle with no interference and all dash lights followed correctly sequence to get fuel. So after fuelling up and restarted ,the yellow dsc and handbrake light came on ffs pulled over. I pulled hand brake up and light went from yellow to red I.e handbrake light,the dsc light stayed on wouldn’t turn off by pushing button.
So turned car off waited several mins and restarted but good news is both above lights went out
A good 70mph 2.5k rpm blast up motorway no lights or issues the dsc button was operational to turn on off which I tried
Slow stop start town driving on way back home,no red oil pressure light,traffic lights stationary @500 rpm, no red flickering light
As I type this I am stationary at home in D foot on Brake car idle 500 just touch over put into Park nothing doing that’s been just over 5 -10 mins in total
32.4 miles just restarted and all is well ….for now no oil pressure or yellow dsc or handbrake light
Cheers

[Charles]

Good news but 500rpm tickover sounds too low - mine sits at about 700rpm once warmed up.

[hap]

I’ll check it again it was over 500

[hap]

See pic

[Charles]

That's nearer 600rpm - but still a bit low in my opinion.

Here's mine at tickover...