Annoying Oil Pressure Readings

3002 tii · 09-21-2016, 08:34 PM

I change my oil every 5,000 miles or 3 track weekends. Up to now, I've relied on the digital gauge to check levels. And frankly didn't matter because I put so little miles on the car during the year. But noticed other day I got a low oil pressure warning on the dash AFTER I turned the ignition off, key still inserted.

So then while the car was off, key still inserted I checked the gauge and got a reading of OK

But start the car up (oil was already at temperature), I get a low reading:

What gives? Again never once got a warning while actually driving...

3002 tii · 09-22-2016, 09:35 AM

I've concluded that I need a new oil level sensor. Anyone done this before?

inTgr8r · 09-22-2016, 12:29 PM

Quote:

Originally Posted by 3002 tii

I've concluded that I need a new oil level sensor. Anyone done this before?

I don't recall any previous posts on this .....

Hopefully the sensor is on an external bung so that the pan doesn't have to come off.

Steeler · 09-22-2016, 12:39 PM

If it is anything like the M54 sensor it is external.
Pan needs to be drained of course.

Karacticus · 09-22-2016, 12:50 PM

Done it on my Z4 and 328xi. You have to pull the reinforcement plate under the front of the car to get at the sensor, but it's otherwise pretty straightforward. They don't give the sensors away though-- looks like almost $200 at Tischer.

But year, it's in the lowest part of the sump, so you have to drain the oil.

The HACK · 09-22-2016, 01:07 PM

Just pull the dipsti...Oh wait.

Sorry, I know. Instead of being a sarcastic, facetious a-hole I could have actually chimed in and helped like the rest of the community here. Still wondering why BMW figured that, hey, if they got an electronic oil level sensor they won't need a physical dipstick, right? Saves us $0.02 per car! Yay!

Marketing may run the world, but the bean counters RULE it.

3002 tii · 09-22-2016, 02:09 PM

Thanks everyone, I'll swap out the sensor when I do my next oil change.

gas-can · 09-22-2016, 02:14 PM

I wouldn't replace it just yet. It seems to be operating as normal.

The warning light comes on AFTER you turn off the key as a reminder you need a small fill up. It does this as a courtesy - if the oil gets really low, it will immediately turn on the lamp with a red colour. That's the serious one. Your's is a gentle nudge.

If you run the check WITHOUT the engine on, it does a static analysis that does a very simple check to ensure you have some oil in the engine.

The second level check (more accurate) requires a warm, running engine. Obviously if you just rebuilt the engine, you don't want to run the engine for 15 minutes before you figure out you forgot to put oil in it. Hence the reason for 2 modes.

I would add a quart, drive for a bit, and check again. I wouldn't replace the sensor immediately, since you might just be a bit low on oil.
-gc

09-21-2016, 08:34 PM	#1
3002 tii Lieutenant General 2282 Rep 12,565 Posts Drives: Z4 M, X5, GX460 Join Date: Apr 2008 Location: CT iTrader: (99) Garage List F15 X5 xDrive35i [8.75] E86 Z4 M [10.00] F10 550i (Retired) [9.17] F25 X3 xDrive35i (R ... [9.43] E82 135is (Retired) [9.50] E85 Z4 M (Retired) [9.41] E90 328i xDrive (Re ... [9.25] E86 Z4 3.0si (Retired) [9.22]	Annoying Oil Pressure Readings I change my oil every 5,000 miles or 3 track weekends. Up to now, I've relied on the digital gauge to check levels. And frankly didn't matter because I put so little miles on the car during the year. But noticed other day I got a low oil pressure warning on the dash AFTER I turned the ignition off, key still inserted. So then while the car was off, key still inserted I checked the gauge and got a reading of OK But start the car up (oil was already at temperature), I get a low reading: What gives? Again never once got a warning while actually driving... __________________ Follow for latest mods Last edited by 3002 tii; 09-22-2016 at 09:35 AM..
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09-22-2016, 09:35 AM	#2
3002 tii Lieutenant General 2282 Rep 12,565 Posts Drives: Z4 M, X5, GX460 Join Date: Apr 2008 Location: CT iTrader: (99) Garage List F15 X5 xDrive35i [8.75] E86 Z4 M [10.00] F10 550i (Retired) [9.17] F25 X3 xDrive35i (R ... [9.43] E82 135is (Retired) [9.50] E85 Z4 M (Retired) [9.41] E90 328i xDrive (Re ... [9.25] E86 Z4 3.0si (Retired) [9.22]	I've concluded that I need a new oil level sensor. Anyone done this before? __________________ Follow for latest mods
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09-22-2016, 12:39 PM	#4
Steeler Colonel 2428 Rep 2,704 Posts Drives: Built not Bought 04 Z4 VF Join Date: Feb 2013 Location: Kitchener Ontario Canada iTrader: (2)	If it is anything like the M54 sensor it is external. Pan needs to be drained of course. __________________ W2A Intercooled Vortech V3Si, custom ducting, Alpha N, 60# Bosch,2.62 pulley, multi port WMI, Severn Tuning(pokeybritches), Tial, magnaflow,SS race muffler, 42 design,3.91LSD, H&R, Hotchkis,ST coils,Konis, Megan camber arms, AKG SS, Nylon mounts, Poly bushings, Carbon interior, CF Aero.APEX
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09-22-2016, 12:50 PM	#5
Karacticus Second Lieutenant 15 Rep 222 Posts Drives: 2007 Z4 3.0si Coupe Join Date: May 2007 Location: Iowa iTrader: (0)	Done it on my Z4 and 328xi. You have to pull the reinforcement plate under the front of the car to get at the sensor, but it's otherwise pretty straightforward. They don't give the sensors away though-- looks like almost $200 at Tischer. But year, it's in the lowest part of the sump, so you have to drain the oil. __________________ 2007 3.0si Coupe Dinan Stage I Suspension (Shocks, Struts, Springs), Ground Control Front Camber Plates, Treehouse Racing Front Control Arm Bushings, RTAB Bushing Limiters
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09-22-2016, 01:07 PM	#6
The HACK Midlife Crises Racing Silent but Deadly Class 1821 Rep 5,337 Posts Drives: 2006 MZ4C, 2021 Tesla Model 3 Join Date: Oct 2007 Location: Welcome to Jamaica have a nice day iTrader: (1)	Just pull the dipsti...Oh wait. Sorry, I know. Instead of being a sarcastic, facetious a-hole I could have actually chimed in and helped like the rest of the community here. Still wondering why BMW figured that, hey, if they got an electronic oil level sensor they won't need a physical dipstick, right? Saves us $0.02 per car! Yay! Marketing may run the world, but the bean counters RULE it. __________________ Sitting on a beat-up office chair in front of a 5 year old computer in a basement floor, sipping on stale coffee watching a bunch of meaningless numbers scrolling aimlessly on a dimly lit 19” monitor.
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09-22-2016, 02:09 PM	#7
3002 tii Lieutenant General 2282 Rep 12,565 Posts Drives: Z4 M, X5, GX460 Join Date: Apr 2008 Location: CT iTrader: (99) Garage List F15 X5 xDrive35i [8.75] E86 Z4 M [10.00] F10 550i (Retired) [9.17] F25 X3 xDrive35i (R ... [9.43] E82 135is (Retired) [9.50] E85 Z4 M (Retired) [9.41] E90 328i xDrive (Re ... [9.25] E86 Z4 3.0si (Retired) [9.22]	Thanks everyone, I'll swap out the sensor when I do my next oil change. __________________ Follow for latest mods
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09-22-2016, 02:14 PM	#8
gas-can Second Lieutenant 25 Rep 204 Posts Drives: 2006 3.0i Roadster Join Date: Oct 2012 Location: USA iTrader: (0)	I wouldn't replace it just yet. It seems to be operating as normal. The warning light comes on AFTER you turn off the key as a reminder you need a small fill up. It does this as a courtesy - if the oil gets really low, it will immediately turn on the lamp with a red colour. That's the serious one. Your's is a gentle nudge. If you run the check WITHOUT the engine on, it does a static analysis that does a very simple check to ensure you have some oil in the engine. The second level check (more accurate) requires a warm, running engine. Obviously if you just rebuilt the engine, you don't want to run the engine for 15 minutes before you figure out you forgot to put oil in it. Hence the reason for 2 modes. I would add a quart, drive for a bit, and check again. I wouldn't replace the sensor immediately, since you might just be a bit low on oil. -gc
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