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Bimmer enthusiast
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Discussion Starter #1
Ok So I am putting along in my car and the oil light flicks on and of real quick and I am like "wth? There's plenty of oil" I get home pop the hood check the dipstick and there is plenty of oil and on the way home the oil light is flickering on and off when I am at a stop light and when I brake. Does this constitute a bad oil pump? I have a slight VC leak but not enough to be pissing out oil. I am checking for leaks and I have maybe over a night period about 8ml collected on a drip pan.
 

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12,388 Posts
could be a faulty sending unit (switch). they can turn the light on when they fail, or get weak. the only way to be certain about the oil pressure is to take a reading with a manual guage. if you don't have one, to buy one would be more than a switch itself (most times).

in order to take a reading, the switch has to be removed anyway, so it may be a guess, but if it were my car i would get a new switch.

other things that could create erratic/low oil pressure would be a restricted sump pickup, weak pressure relief spring (in the pump), and worn pump gears.

hope this helps.


df
 

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BMWCCA 149159
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2,876 Posts
I am willing to bet you your sending unit is fine. The oil light flickers when you get 6 psi of pressure or less. At idle it should be 10 psi or more. Not sure what viscosity oil you are running but you might wish to use a heavier viscosity.

May not be the oil pump but bearing because the pressure is bleeding off someplace. I run 15W50 in Florida because it never get too cold here for more than a day or so. Texas is pretty similar.

the only time I have seen a oil pressure flicker light is when I pulled the head on my 275K mile M3 vert and refreshened the valve train and VANOS. The head gasket break in procedure I used was warm up at idle until the tstat opens and shut it off. Repeat again. Than 30 minutes at 1000-1400 rpms. When I did that on a hot day and after the 30 minutes I got the oil pressure flicker which never surprised me since the engine was very warm sitting doing this.
Since changing the oil and running 15W50 I have never seen this again....
 

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FixItFaster
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I am willing to bet you your sending unit is fine. The oil light flickers when you get 6 psi of pressure or less. At idle it should be 10 psi or more. Not sure what viscosity oil you are running but you might wish to use a heavier viscosity
This is very interesting I did not know this! Thanks. :thumbup:
 

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Bimmer enthusiast
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564 Posts
Discussion Starter #6 (Edited)
I am willing to bet you your sending unit is fine. The oil light flickers when you get 6 psi of pressure or less. At idle it should be 10 psi or more. Not sure what viscosity oil you are running but you might wish to use a heavier viscosity.

May not be the oil pump but bearing because the pressure is bleeding off someplace. I run 15W50 in Florida because it never get too cold here for more than a day or so. Texas is pretty similar.

the only time I have seen a oil pressure flicker light is when I pulled the head on my 275K mile M3 vert and refreshened the valve train and VANOS. The head gasket break in procedure I used was warm up at idle until the tstat opens and shut it off. Repeat again. Than 30 minutes at 1000-1400 rpms. When I did that on a hot day and after the 30 minutes I got the oil pressure flicker which never surprised me since the engine was very warm sitting doing this.
Since changing the oil and running 15W50 I have never seen this again....
Thanks! I am due for an oil change soon so i'll up my viscocity and hope for the best!
 

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Bimmer enthusiast
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564 Posts
Discussion Starter #8
sending unit was extremely faulty by way of pushing oil out! LOL! went to my local bmw dealer and got the sending unit for $8.07USD and knocked out my turn signal issue with getting a new relay and voila! everything is fixed. still need to do the valve cover gasket job. just got my newish stock alarm for my car from bravarian auto recycling they are so win. plugged it in and it works! i is happy again.
 
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