Oil level sensor malfunction

[bmwlover0725]

I just wanted to reach out to people here after reading some different topics to ensure that my problem is accurately diagnosed. My oil was reading at the half way mark after a few thousand miles so I added half a quart the other day. At first it was still showing at half, but it ended up correcting itself after I reset it.

Today I was driving and noticed that it was reading one notch low. I figured I may have been slightly off (or the sensor was) so I added a quarter quart. It still read wrong after a few times of resetting it so I added another quarter of a quart.

It's still reading one notch down and I have surely filled it properly (if not overfilled slightly) and do not want to damage my engine by endlessly dumping oil into it. It burns the average amount of oil that any M3 would so I know my level is high enough right now. I'm wondering if it may be the sensor going bad. I placed an offer on a new sensor on eBay for 15 bucks just to give it a shot in hopes that it will correct the problem. I'm not normally a fan of used parts for things like this, but for almost 200 bucks less, I couldn't argue with it.

Let me know what you all think. Thanks!

tl;dr - Oil level wont read full, but I know I have more than enough. Is my sensor bad?

[BayE30]

I have had this issue, it took about 2 weeks for the sensor to read correctly for me.

[Helmsman]

OP, you'll find about a million threads on this very subject out there. You're not alone, if you know for certain there is oil enought no need to worry. Even if still very annoying....

[bmwlover0725]

Why can't I just be patient? Well I drove about 100 miles today and it started showing it as overfilled so I guess its fixed. Now I have to wait a few thousand miles for it to go down. I may just change the oil anyway since I haven't done it since my rod bearings.

[Scharbag]

Originally Posted by bmwlover0725

Why can't I just be patient? Well I drove about 100 miles today and it started showing it as overfilled so I guess its fixed. Now I have to wait a few thousand miles for it to go down. I may just change the oil anyway since I haven't done it since my rod bearings.

Been there, done that, bought a new sensor...

Get a new sensor from FCP - quick to change when you drop your oil. And if you get it from FCP, the next time it bites the green weenie, you have warranty.

[CurbBender'90]

I recently did my rod bearings and after, I added too much oil based off calculations and the dipstick only read the notch below full which wouldn't make sense, it was taking a very long time to read also. I scanned the car and my oil sensor was reading faulty. I ordered the Hella brand one and have been good since. I personally wouldn't trust a used one, could have the same existing problem.This was just this week by the way. https://www.fcpeuro.com/products/bmw...607910#fitment

[testdriver]

I have the same issue like you...... but the sensor show low on oil even I'm 100% sure i have enough. Given the engine will burn little oil over time, it is annoying to "see"/ "show" you don't have enough in there.

I have the Carly reader and it won't help from on the Oil Level Raw date as it got the reading from the same sensor too... anyway, I decide to buy a new sensor and will replace it soon.

[bmwlover0725]

Originally Posted by testdriver

I have the same issue like you...... but the sensor show low on oil even I'm 100% sure i have enough. Given the engine will burn little oil over time, it is annoying to "see"/ "show" you don't have enough in there.

I have the Carly reader and it won't help from on the Oil Level Raw date as it got the reading from the same sensor too... anyway, I decide to buy a new sensor and will replace it soon.

Yeah my level is now reading as perfect even though its completely over filled. I already have a new one ready to go in when I change the oil.

[omgzirra_exe]

it took about 2 weeks for my oil level to read at max. i was slightly over filled by a 1/4 just did a lot of max rpm driving for a while then it leveled properly. lol

[L4ces]

Originally Posted by ohmygodzirra

it took about 2 weeks for my oil level to read at max. i was slightly over filled by a 1/4 just did a lot of max rpm driving for a while then it leveled properly. lol

Good thing you did not weaken or cause a head leak or something from the extra oil. If you notice more oil consumption in the future... I often wonder if that is what I've done to mine (regardless of having 197K on the dial.

[Scharbag]

Originally Posted by L4ces

Good thing you did not weaken or cause a head leak or something from the extra oil. If you notice more oil consumption in the future... I often wonder if that is what I've done to mine (regardless of having 197K on the dial.

You would have to fill the pig to the tits to hydro lock the engine. Lol

These sensors are such bullshit. I just replaced mine and again, it says +1L. I was Leary given my mileage so I added 0.5L. Went from +1L to top fill line. At least it is not saying overfilled.

[omgzirra_exe]

Originally Posted by L4ces

Good thing you did not weaken or cause a head leak or something from the extra oil. If you notice more oil consumption in the future... I often wonder if that is what I've done to mine (regardless of having 197K on the dial.

the overfill wasn't even by a lot. that extra quart was added because it made me add it LOL. it read maybe 1/16th above the max line.

[L4ces]

Originally Posted by ohmygodzirra

the overfill wasn't even by a lot. that extra quart was added because it made me add it LOL. it read maybe 1/16th above the max line.

Ok, cool.

BTW, I successfully removed lots of oil by sucking it out of the oil filter compartment using a baster (aka turkey batter) to suck it out of the oil filter compartment. I read that technique in a similar thread.