Low Oil Pressure Light on E90

[Dan R]

Hi - The oil pressure light has popped up a few times over the last 12 months of having my 2011 318i (E90). It always happens when I come off a motorway and slow down for traffic lights, junction etc. It pops up, the car runs as perfect as always with no noise, knocking or anything and then when I turn the engine off and on again, it disappears as quickly as it came. 
 

it is a bit weird and a few mechanics have given different diagnosis (based on assumptions rather than looking at the moment). My actual mechanic reckons if it was an actual real problem with my oil pressure then it would have destroyed my engine already and not continued perfectly over the last 12 months so reckons its a software issue but I thought I’d check here to see what people think.

it’s been serviced recently and this issue cropped up before and continues to do so afterwards so I’m positive it isn’t the oil filter etc.

so far, I’ve been told oil pump, crankshaft, timing chain debris in oil sump with one garage reckoning around £1000 to fix but with the car running no problem, I am reluctant to just hand the car to them with my debit card as it really doesn’t feel mechanical. I am however, NOT a mechanic!!

Any thoughts/ideas??

[Greydog]

Morning Dan

Welcome to the Forum

About the age of your car BMW decided to rely on oil pressure/level sensors to provide information on the display about pressure/level.

So does your car have a dipstick? How often is oil level checked? Low oil level can trigger the warning as can wrong oil or even just wear and tear oil pumps are mechanical and don't last forever. How many miles has your engine covered?

Another culprit could be just a loose connection or faulty oil level/pressure sensor, has the sensor loom and connector been checked/cleaned? Ensure oil level is correct.

If you are currently running a 5W30 grade synthetic oil you could go to a 5W40 grade to see if that helps. Your Handbook should give a list of oils you can use.

Dave

[Dan R]

Hi - Thanks for your reply. My car has done 66k so quite low mileage. Now the service has just been done and they put Sw30 in it. I have no dipstick , just an electronic gauge, but that reckons 3/4 full. I might just too it up a bit as it does burn a little bit of oil.

It seems that you are thinking electrical too though maybe?

[Dan R]

Sorry, 5W30!! Damn predictive text!!!

[Greydog]

Makes it fun though Dan you see your own message and think who sent that 🤣

Yes electrical gremlins, I spent years in business with Industrial Controls sensors hate Vibration, Heat, Moisture and I guess the poor old sensors now get the lot. For oil I never trust them fortunately my X5 has a dip stick (according to my wife 2 one behind the wheel one in the engine 🤣)

If I recall to change the oil level sensor you have to drain the oil so it may be awhile before that can be done, but checking cleaning and re-connecting the sensor plug. Getting someone to wiggle it while the engine is running see if the light flashes same with the loom wiggle see if gives a flash.

Good Luck 

Dave

[Dan R]

Quick update….. so, from what you were saying, it looks like the amount of oil may have been low despite the level saying 3/4 full. I have added an extra 2.5 litres to it (in 0.25 increments) and it still says 3/4 full but the problem has now stopped following a good blast up to M6 to IKEA and back. Interestingly, the clutch judder also appears to have gone too which started a week or so back (another issue I thought). 
The interesting thing though is that I had it serviced literally three weeks ago which is when the problem has become more severe so I am wondering if they even changed the oil????

Booked in now for Monday for an oil change (again) at a different garage and they are going to look at the oil filter to establish whether the oil really was changed at the last service or if I have been ripped off. Depending on what they report back will determine how I take it forward. Worst of all, the last garage left both my rear wheels loose to the point where I lost two wheel nuts a couple of weeks back . The knocking noise led me to jack it up and check. They were literally hanging on by a thread, I managed to easily take them off using just my fingers they were so loose! Unbelievable, so a massive complaint on the horizon probably. 
Thanks for the input though, they are going to check the oil level indicator sensor as you suggested when they change the oil so hopefully the problem will stay gone and I’ll have an accurate idea of how much oil I have in the engine.

Dan.

[Greydog]

Morning Dan

Sounds like your last service garage was at best incompetent !!!!! At worst dangerous

Following your observation that the level sensor indicated 3/4 even after you topped it up I would get it changed as a matter of course when they are doing the service/oil change. It is important as overfilling can do almost as much damage as low oil. 

Dave

[Ian J]

On 8/18/2021 at 7:03 AM, Greydog said:

Morning Dan

Sounds like your last service garage was at best incompetent !!!!! At worst dangerous

Following your observation that the level sensor indicated 3/4 even after you topped it up I would get it changed as a matter of course when they are doing the service/oil change. It is important as overfilling can do almost as much damage as low oil. 

Dave

Hi, my 318 2.0l petrol does exactly the same thing, I’ve had it checked by a plug in tester an there’s no code there! 
so I’m having the pressure sensor changed. 
the engine wa rebuilt less than 3000 miles ago due to a recall that had all the timing chain replaced with all associated parts. They didn’t want to release it until it was perfect and then a couple of hundred miles later it started again. 
There’s no noise when the message goes off so I know there’s plenty of oil. It’s only when I come off the revs 

I don’t drive hard so literally a 30 mph drive for 8 miles and stop does it!! 
 

I keep the car covered in cotton wool. It’s a 2010 model with 64000 miles 

just spent £400 on rear tyres as it was a mot advisory only 

I’m going to try the 5w 40 though it’s got 5w 30 in at present 

thanks

Ian

[Dan R]

On 3/11/2024 at 3:26 PM, Ian J said:

Hi, my 318 2.0l petrol does exactly the same thing, I’ve had it checked by a plug in tester an there’s no code there! 
so I’m having the pressure sensor changed. 
the engine wa rebuilt less than 3000 miles ago due to a recall that had all the timing chain replaced with all associated parts. They didn’t want to release it until it was perfect and then a couple of hundred miles later it started again. 
There’s no noise when the message goes off so I know there’s plenty of oil. It’s only when I come off the revs 

I don’t drive hard so literally a 30 mph drive for 8 miles and stop does it!! 
 

I keep the car covered in cotton wool. It’s a 2010 model with 64000 miles 

just spent £400 on rear tyres as it was a mot advisory only 

I’m going to try the 5w 40 though it’s got 5w 30 in at present 

thanks

Ian

Hi Ian - Yeah, I must admit, I completely forgot about this post. So in the last three years, the problem has persisted on occasion but to no detrimental effect on the car. I just tend to put up with it these days on the grounds that in three or four years of it doing this, no harm seems to have come to it.

Ill be trading in within the next 12 months so hopefully my next one will be without the oil pressure light issue!😂

[bertatronics]

***OIL PRESSURE WARNING SOLVED***BMW E90 with same issue. Intermittent Oil Pressure Warning light for around a year. No performance issues or strange noises.Started when slowing down coming off highway and then progressed to when driving around town as well.Tried a can of Wynn's Super Charge Oil Treatment and after a few days light stopped coming on around town but still after highway driving. Bought another can and poured that in and six months later no warning lights. Guessing will have to do this again after next oil change but so far so good. Car running and sounding better also.

[Greydog]

Hi Stewart

Welcome to the Forum

Rather than try an additive which increases viscosity I think I would have changed the Oil Pressure switch first. Then maybe the Pressure relief valve on the oil pump needs invetigating, after all oil is the life blood on your car.

Fingers crossed it is a genuine fix for you remember you can use higher viscosity oils 5-40 instead of 5-30

Dave