# Low Oil Pressure Warning & Can***8217;t Measure Oil Level



## Dallasfan (Jun 26, 2018)

Hi... I have a 2013 BMW X3 and been consistently receiving the code "low oil pressure warning" ? I've brought to mechanic -had oil changed as well as filter- oil pumped was checked in good condition..Also I'm not able to measure the oil level from the IDrive - the test stops at 17%.. any ideas as to why this could be!? Struggling with possible problem being:

1) software update!? 
2) Sensor issue!?
3) Hydraulic valve replacement!? 

Any help is so much appreciated!


----------



## Doug Huffman (Apr 25, 2015)

What is the independently measured oil pressure?

To continue to run a motor with a low oil pressure ALARM generally makes things worse as the connecting rod bearings over heat, soften, and pound themselves into slag.


----------



## Dallasfan (Jun 26, 2018)

I***8217;m thinking this is more of a sensor /software update issue!? Since I***8217;m not able to run the diagnostic test from the IDrive...


----------



## Doug Huffman (Apr 25, 2015)

Maybe, but you are betting that YOU are smarter than the most fundamental alarm in an engine.


----------



## timfitz63 (Aug 10, 2010)

Dallasfan said:


> I'm thinking this is more of a sensor /software update issue!? Since I'm not able to run the diagnostic test from the IDrive...


I would tend to agree. I doubt the system would suddenly stop working for lack of a software update (but stranger things have happened...), so I would lean toward sensor problems (either loose connections or the sensor itself).

Still thinking in the vein of computer/electrical glitches, you might try simply resetting the computer by disconnecting the negative battery lead for a few minutes, then reconnecting it. That may clear up any 'confusion' the computer might have developed. Can't say why cycling power on computers sometimes makes things work again, but in many cases it does -- _if_ that's the problem... Be aware: when you disconnect power on these late-model BMW's, you'll often have to go through a litany of reset procedures on things like the panoramic roof, power windows, steering, etc. to have _their_ sensors 're-learn' their physical travel limits and such so that all of their features (e.g., auto-open/shut) work properly. The reset procedures aren't particularly difficult to do and usually just require manually operating the affected systems to their physical limits; but the F25 forum folks or a BMW-savvy mechanic would probably be better-equipped to advise you what would need to be done on your particular generation of X3.

In my experience, oil pumps tend to be more reliable than sensors; I can't ever recall replacing an oil pump on _any_ vehicle I've ever owned -- and I currently own a 29-year-old Pontiac Firebird -- but I've seen some intermittent but quirky behavior in the oil level sensor of my X3, and (coincidentally) had to replace a failed oil pressure sensor in the Firebird back when it was only a few years old...

So if you've changed the oil and filter, thereby ensuring the engine is definitely topped off with oil, the oil pump has been checked for good operation, and there are no signs of an oil leak, by process of elimination it's got to be the sensor... Not sure how troublesome or expensive it is to swap out the sensor on an F25 X3; but if resetting the computer fails to correct the problem, that would be my next move in your situation.


----------



## Dallasfan (Jun 26, 2018)

dear timfitz63...thank you so much for your thorough reply...I actually brought the X3 this morning to the dealer and wow -how they try to rip you off but that's an entirely different story...so after performing the diagnostic test dealer mechanic was able to determine 2 things:

1) need a new oil level sensor (reason why I could not perform the oil measure test via IDrive)
2) the oil pump is failing (reason for low oil pressure warning)


----------



## Doug Huffman (Apr 25, 2015)

Dallasfan said:


> 2) the oil pump is failing (reason for low oil pressure warning)


So, you had a low oil pressure condition and kept the engine running without consequences? That***8217;ll be a surprise.

You don***8217;t say which engine you have. An X3 has a combined oil temperature and pressure sensor that sets a DTC error on failure of the sensor.


----------



## timfitz63 (Aug 10, 2010)

Dallasfan said:


> dear timfitz63...thank you so much for your thorough reply...I actually brought the X3 this morning to the dealer and wow -how they try to rip you off but that's an entirely different story...


No worries. Yeah, they aren't referred to as "stealerships" for no reason... 



Dallasfan said:


> ...so after performing the diagnostic test dealer mechanic was able to determine 2 things:
> 
> 1) need a new oil level sensor (reason why I could not perform the oil measure test via IDrive)
> 2) the oil pump is failing (reason for low oil pressure warning)


Wow, a dual failure...?! Sensor _and_ pump...?! That's not at all typical; but hey, someone beats the odds every now and again...

How did your mechanic test the pump when you took it to him? You said he determined it to be in good working order... Either your mechanic or the BMW mechanic is wrong about the oil pump... I think I'd talk to them both about their respective findings on the pump before replacing that component...

Not that I don't trust anyone -- but frankly, I don't when it comes to my money and their parts & labor. Many mechanics -- in particular dealership mechanics -- want to just replace components before fully diagnosing a problem. It's conceivable that the sensor is the only failed component and the low pressure error code is only a result of that; failed sensors don't always manifest themselves in the ways you expect. The failed oil pressure sensor on my Firebird caused the _fuel_ pump to run continuously, even when the engine was off. The reason was the way GM wired it all together: apparently the fuel pump has an input from the oil pressure sensor that detects the rise in oil pressure as the engine is cranked at start, and it knows then to supply fuel to the engine. The failsafe condition when the oil pressure sensor goes bad is to latch the fuel pump "ON" -- presumably so you could limp somewhere with the vehicle because the dashboard oil pressure gauge (apparently separate from this other oil pressure sensor in the Firebird) is really the final authority on what the engine is seeing, and the driver can monitor that to determine whether it's safe to continue operating the engine. Still, it wasn't immediately apparent why the fuel pump wouldn't shut off; and my initial conclusion, based on the circumstantial evidence was the fuel pump itself was to blame...

Point is: without a full understanding of what conditions actually generate a low oil pressure error code in the F25, the BMW dealership might be recommending the replacement of a perfectly good oil pump because the circumstantial evidence points that way -- when a faulty oil level sensor might generate the same error code (because, yeah, a low oil level will result in low oil pressure as well...). If the sensor has failed reading low -- or that's it's design, default failure condition, in order to prevent you from continuing to drive without a functioning oil pressure sensor -- it might generate the same error code as a failing oil pump.. Just spitballing here...

But again, I'd get more details from both your mechanic and the dealership on what led them to their respective conclusions about the oil pump. If nothing else, at least then you're making an informed decision about its replacement.


----------



## ECSTuning (Feb 25, 2009)

Oil pressure switch is a very very common cause of your symptoms, I would start there. On most cars, it's going to be fairly easy to change out during an oil change. 

-James


----------



## Dallasfan (Jun 26, 2018)

timfitz63 said:


> No worries. Yeah, they aren't referred to as "stealerships" for no reason...
> 
> Wow, a dual failure...?! Sensor _and_ pump...?! That's not at all typical; but hey, someone beats the odds every now and again...
> 
> ...


THANK YOU!! you are exactly right an what you've stated this is what my independent mechanic suggested to me about the failing sensor tripping the low oil pressure msg!


----------



## Dallasfan (Jun 26, 2018)

ECSTuning said:


> Oil pressure switch is a very very common cause of your symptoms, I would start there. On most cars, it's going to be fairly easy to change out during an oil change.
> 
> -James


YESS!! thank you for that! based on the advice of my mechanic I am going to have the oil level sensor changed first then a wait and see if the low oil pressure msg returns


----------



## Dallasfan (Jun 26, 2018)

ECSTuning said:


> Oil pressure switch is a very very common cause of your symptoms, I would start there. On most cars, it's going to be fairly easy to change out during an oil change.
> 
> -James


thanks James!! can you advise if the 'oil level sensor' and 'oil pressure switch' are one and the same?


----------



## Dallasfan (Jun 26, 2018)

You don't say which engine you have. An X3 has a combined oil temperature and pressure sensor that sets a DTC error on failure of the sensor.[/QUOTE]

its the 28i 4cylinder


----------



## Dallasfan (Jun 26, 2018)

Doug Huffman said:


> So, you had a low oil pressure condition and kept the engine running without consequences? That'll be a surprise.
> 
> You don't say which engine you have. An X3 has a combined oil temperature and pressure sensor that sets a DTC error on failure of the sensor.


the engine is 28i


----------



## Doug Huffman (Apr 25, 2015)

*Mapped oil pressure supply*

https://www.newtis.info/tisv2/a/en/...cs-msv/engine-oil/oil-pressure-sensor/Y4YOM3Z


----------



## Dallasfan (Jun 26, 2018)

Dallasfan said:


> Doug Huffman said:
> 
> 
> > So, you had a low oil pressure condition and kept the engine running without consequences? That'll be a surprise.
> ...


----------



## Doug Huffman (Apr 25, 2015)

Dallasfan said:


> thanks James!! can you advise if the 'oil level sensor' and 'oil pressure switch' are one and the same?


They are not.

Study your engine at www.NewTIS.info.


----------



## Dallasfan (Jun 26, 2018)

Dallasfan said:


> Dallasfan said:
> 
> 
> > So would you say that the 2 current issues of "low oil pressure" code (which only comes on periodically and not permanently) in addition to not being able to measure the oil level via IDrive could be a DTC error? Dealer mechanic confirmed oil level fine and clean.
> ...


----------



## Dallasfan (Jun 26, 2018)

Thank you to ALL for your genius insight! For those of you that had said ***8216;sensor***8217; issue- you were correct!!! ..my independent mechanic suggested we start with replacing both the oil level sensor and the oil pressure switch- rip off dealer mechanic said to replace oil level sensor as well as replace COSTLY oil pump (claiming the low oil pressure warning was a result of failing oil pump (WRONG)!!! Per the dealer mechanic why he had advised to replace oil pump despite oil being clean, no apparent leaks, level of oil was fine and pump was not in any way distressed - just sends alarm bells of how dealer price tag of $4000 to repair is a scam!! Car is running great with having only those mentioned sensor and switch replaced by my HONEST independent mechanic! BMW you need to do better!!


----------



## DBU (Dec 15, 2005)

Dallasfan said:


> Thank you to ALL for your genius insight! For those of you that had said 'sensor' issue- you were correct!!! ..my independent mechanic suggested we start with replacing both the oil level sensor and the oil pressure switch- rip off dealer mechanic said to replace oil level sensor as well as replace COSTLY oil pump (claiming the low oil pressure warning was a result of failing oil pump (WRONG)!!! Per the dealer mechanic why he had advised to replace oil pump despite oil being clean, no apparent leaks, level of oil was fine and pump was not in any way distressed - just sends alarm bells of how dealer price tag of $4000 to repair is a scam!! Car is running great with having only those mentioned sensor and switch replaced by my HONEST independent mechanic! BMW you need to do better!!


Not defending the Stealership here, BUT keep in mind that:
- The SA is a salesman whose job it is to upsell you as much as possible AND to write up big orders for his mechanic friend in the back (who you likely never talked with).
- Also, dealers will always replace all parts that conceivably could be the problem. Who wants to return to the dealer several times because they didn't cover all the bases the first time around?

On a different note, your symptoms could also be caused by the infamous timing chain issue. The logic (from the stealership) goes like this:
- low oil pressure is the first warning sign of a failing timing chain (small plastic bits coming off the plastic guide gets caught in the oil pump sump filter) = failing oil pump symptoms.
- The timing chain is kept tight by a chain tensioner which gets its power from the oil pressure. Low oil pressure = low timing chain tension = extra strain on the plastic guide = plastic guide comes apart (maybe) = timing chain jumps and no sticks a valve in the engine at the wrong time and the piston and valve collides = new engine.


----------

