"Stop Engine Oilpress" Message at low RPM

[Bdc101]

Thanks for all the input guys. I think I'm going to drive it home this evening since I am at work and it made it here safe. And just make sure to keep the revs up. I'll check things out and order a new pressure sensor tomorrow as well as anything else I feel like I should replace. Also, I can park the car for at least a week.

If it throws the error cold, then your oil pump has lost prime and probably needs to be replaced.

I don't think oil pumps can lose prime unless the suction pipe has a hole in it, or the pump has a chunk taken out of it. They are positive displacement gerotor type pumps.

Check those o-rings. If one of them has failed part of the oil pressure is lost directly back to sump.

I will check this tonight, thanks for the suggestion. (I don't have keep my 34mm socket in my car, or I would do it here.)

[bmw540san]

Have you tried to check the resistance values on on the oil pressure switch itself?
That is one sure way to know if the sensor is bad before replacing it.
I think Bentley has the correct resistance value.
I also vote for checking the oil pressure independently and go from there.

[nick325xit 5spd]

Originally Posted by Bdc101

I don't think oil pumps can lose prime unless the suction pipe has a hole in it, or the pump has a chunk taken out of it. They are positive displacement gerotor type pumps.

The pumps can wear out. I've had that experience personally with S54 pumps.

[80stech]

If the Vanos seals are leaking you can have low oil pressure at idle, especially hot. Try adding something to thicken the oil a bit like STP just to help with diagnosing the problem.
Typically though, the light will flicker at first and get progressively worse.

[Bdc101]

Originally Posted by 80stech

If the Vanos seals are leaking you can have low oil pressure at idle, especially hot. Try adding something to thicken the oil a bit like STP just to help with diagnosing the problem.
Typically though, the light will flicker at first and get progressively worse.

Where do the VANOS seals leak into? Would this be visible from outside the car or do they leak back into the crankcase?

Also would this happen instantaneously? I have never seen the low-oil-pressure light before today and now it is happening whenever the car is warm and at idle.

Originally Posted by bmw540san

Have you tried to check the resistance values on on the oil pressure switch itself?
That is one sure way to know if the sensor is bad before replacing it.
I think Bentley has the correct resistance value.
I also vote for checking the oil pressure independently and go from there.

I will check this tonight. I do have a Bentley manual. Fortunately I can park the car for a few days. Is the sensor located in an accessible place?

[Bdc101]

Just drove home and it drove fine. It didn't start popping up the oil light until I was a couple of blocks from home. I just kept it in gear and shut it off at stop lights. I will park it for a few days until I can diag the issue. Unfortunately I did check and the Foxwell won't tell me the actual oil pressure. I will try with BMW Scanner tonight to see if that will show me.

[80stech]

The Vanos seals leak into the crankcase so nothing visible. The oil feed for the Vanos is an external line so might try pinching that off to see what happens. I guess it is possible that you actually blew a Vanos seal which would explain your symptoms.
You won't get an oil pressure reading from a scan tool because there is no sensor for the DME to read it.

[Bdc101]

Gotcha, I was thinking it was a pressure transmitter, but if it is just a switch then that would make sense.



Is there a way to diagnose a blown out VANOS seal? Would it throw a Vanos code?

[80stech]

I think the best thing to do would be to pinch off the Vanos line while watching the oil pressure or the oil light. I haven't tried this myself though.

[Bdc101]

Yeah I actually just was searching on bimmerfest and found the exact same suggestion. Will try it tonight. Thanks!