Was the Low Oil Pressure light RED? It means stop the engine immediately and do not run the engine again until proper lubrication is assured. It is bricked, dump it. It is on you.

The only reason that automobile engines don’t have Low Oil Pressure automatic SHUTDOWN is for the larger safety issues of stopping in dangerous traffic situations.

 

It is bricked, dump it. It is on you.

Thanks for your reply Doug - albeit alarmist and unhelpful. I'd say you've made some substantial assumptions to reach that conclusion. If I wrote off this car as soon as I got a red warning light of some description it wouldn't have lasted a week, and would have been written off at least three times since.

The car is most certainly not 'bricked' - my mechanic has confirmed that - and I have no intention of 'dumping it' unless identifying the root cause becomes prohibitively expensive. The forums are littered with folk who have had the BMW low oil pressure light and have resolved the issue with no engine damage. I intend to be one of that number. I'm just after a little assistance from the more helpful folk on this forum to help get me there.

 

We all have a view of Doug over the years !! He is definitely not a Nostradamus , have some patience for some of the other guys to come online, remember this is mostly an American site so time differences make a big difference. This is one of the best sites I know for help so hang on !!!

 

650 or 645? Herb is the expert on low oil pressure. He fought it for a while on the 645. You need to check the orings for your VANOS solenoids and look for major leaks around the valve & timing covers. How many miles? Ever done valve covers? Look at the sensors on the covers for leaks as well. Maybe smoke the engine? Have you hook it up to ISTA?

 

If the oil filter check valve came apart, it is possible that it could have made it into the oil pump, & into the oil pressure line that feeds the oil to the complete engine. I will attach the oil feed line drawing, & an internal pic of the oil pump. This might help you understand what you are looking at, & how the oil flows thru the engine. It is possible that a piece could have gotten thru the oil pump, & into the feed lines. Is the oil light coming on very soon, or after the engine gets warm? Has any work been done on the Vanos solenoids lately? The oil pressure switch is at the end of the line once it goes thru the Vanos system on the passenger side head, thru the upper timing cover, then onto the oil pressure switch. I would remove the OP switch, & install an oil pressure test gauge. This can be found at Harbor Freight for less than 20.00, but you will need an adapter fitting that will allow the test guage to be connected. This is the same fitting that is used on an GM LSx engine. I have 2, but I think I got them from Amazon. It you add a 1/4" T, you can install the test guage & OP switch at the same time. If the OP warning goes off, you can verify if the warning is real, or a bad switch? You can take the 6 non-return valves out, & blow some air back thru the oil passages. You need to insert a bolt that will block the lower port, then blow the air thru the feed passage. If there is a blockage, this might help blow it back to the oil pan. The larger volume amount of air, the better the results.

Does the motor start to make any noise as a loss of lubricant, or does everything sound ok? I don't advise to drive the car this way, until you find the problem. What work was done before this started?

 

Thanks for the replies HerbP and Mulchman. Apologies for the delay in responding, I've been dealing with a family bereavement, and also my other car being stolen 🤬

Thanks for attaching the pics - the oil circuit is really useful. In answer to your questions:-

• The oil light comes on pretty much immediately
• No work has been done on the Vanos solonoids - until I took them out the other day as part of this diagnosis, that is. The solonoids on bank 1 were clean as a whistle, but bank 2 were quite clogged up with filter debris.
• Same for the six oil check valves. Bank 1 - clean; Bank 2 - two of them had filter deposits, in particular the one that's hardest to get to. That one had loads of oil filter in it.
• My garage have already tested the oil pressure and it's very low - so the car is not being driven at all.
• When the car is started (only for idle) it sounds okay - but I'm still not going to drive it.
• I replaced the oil pressure switch with a new, genuine BMW part, and the light still came on - so I don't think that the pressure switch is at fault.

Given that the oil pressure switch is on the bank 1 side, and there are no filter deposits on the bank 1 solonoids or check valves, would it be fair to conclude that it may well be the oil line to bank 1 that is more heavily clogged at an earlier point in the oil flow?

My next step was going to be to drain the oil, remove the lower oil pan, and see what I can see with the endoscope. I like your suggestion of blowing air back down the passages - but what do you mean by "insert a bolt that will block the lower port", and which passage is the "Feed Passage"?

Thanks again for your help.

 

The oil enters the non-return valves from the inner part of the block, then drains back down the bottom of the check valve. Inserting a bolt in the lower hole, will force the oil back to the oil pump path. Based on the info you have provided, I would pull & replace the check valve stem in the oil filter. If the valve fails or was removed when the oil filter was removed, the oil will bypass the pump, causing a immediate oil pressure alarm. Most BMW shops don't keep the valve stem on the shelf, but can get it the next day. Some local shops that work on many types of cars, don't pay attention if the valve stem comes off with the filter.

Lubrication system-Oil filter

Lubrication system-Oil filter | BMW 6' E63 645Ci N62 USA

bmwfans.info

The Vanos system provides the path of oil to the oil pressure switch on the passenger side of the head. If the Vanos solenoids are moved to a different location, the adaptations must be reset. New Vanos valves installed must also have the adaptations reset also, as they will not operate properly if not reset. Not resetting the adaptations will allow the oil to flow thru the solenoids, not making it to the oil pressure switch. The switch is the last item to see the oil flow. I tore my complete engine apart hunting for the source of my oil pressure problems, & found nothing that would cause the problem. I added a T on the oil pressure switch & have an oil pressure gauge to monitor, if the alarm goes off. Before resetting my adaptations, I would get down to 8 psi, which triggers the alarm. After resetting the adaptations, my oil pressure jumped from 8 psi, to 18 psi. I could not believe what I saw, after resetting the adaptations. I was shocked & relieved when I saw the oil pressure jump that much. This is how important the Vanos system is, for controlling the oil pressure.

 

The oil enters the non-return valves from the inner part of the block, then drains back down the bottom of the check valve. Inserting a bolt in the lower hole, will force the oil back to the oil pump path. Based on the info you have provided, I would pull & replace the check valve stem in the oil filter. If the valve fails or was removed when the oil filter was removed, the oil will bypass the pump, causing a immediate oil pressure alarm. Most BMW shops don't keep the valve stem on the shelf, but can get it the next day. Some local shops that work on many types of cars, don't pay attention if the valve stem comes off with the filter.

Lubrication system-Oil filter

Lubrication system-Oil filter | BMW 6' E63 645Ci N62 USA

bmwfans.info

The Vanos system provides the path of oil to the oil pressure switch on the passenger side of the head. If the Vanos solenoids are moved to a different location, the adaptations must be reset. New Vanos valves installed must also have the adaptations reset also, as they will not operate properly if not reset. Not resetting the adaptations will allow the oil to flow thru the solenoids, not making it to the oil pressure switch. The switch is the last item to see the oil flow. I tore my complete engine apart hunting for the source of my oil pressure problems, & found nothing that would cause the problem. I added a T on the oil pressure switch & have an oil pressure gauge to monitor, if the alarm goes off. Before resetting my adaptations, I would get down to 8 psi, which triggers the alarm. After resetting the adaptations, my oil pressure jumped from 8 psi, to 18 psi. I could not believe what I saw, after resetting the adaptations. I was shocked & relieved when I saw the oil pressure jump that much. This is how important the Vanos system is, for controlling the oil pressure.

Hey herb I know this is an old post but what software did you use to reset adaptations I have tried everything including a new oil pump and am still getting low oil pressure

 

BMW Standard Tools, or ISTA D

 

What was the fix in the end? I'm having this same issue, putting the 2007 550i with the 4.8l N62 up on the lfit tommorow to check the oil pick up just in case. I have reset all engine adaptations including the CES oil increiment adaptation

 

Reset your Vanos adaptations, & this should help. If the Vanos solenoids have been moved to a different location, they will not allow the proper oil flow at that point. I chased this for several months, before locating the problem. The lower oil pan comes off easy,& give you access to the oil pump strainer. If you find nothing at the strainer, you might need to pull the 6 non-return valves, located on the front of the intake area, on the heads.

 

I rebuilt the engine to bare block. Yeah i have 6 new oem check valves installed, already checked oil. Still haven’t removed the oil pan yet but tomorrow i will. ISTA+ does not have an adaptation labeled VANOS for the N62 for some reason.