Oil service light? Runs out...when?

[Guelphguy]

Kinda simple question, but what the oil service light bar on the dash base it's status on? I have driven 3800km since I reset it and changed the oil and it has not even gone down one green bar yet?

[Paul in NZ]

it will change very soon

[infinity5]

I'm pretty sure on our older cars the OBC or whatever uses inputs from varioussensors to determin when you should change you oil. How you drive will affect how fast the bars change... right?

I think the newer cars rely on just fuel consumption data? I don't know for sure.

[Paul in NZ]

mine has been pretty consistent but i beleive even the m39 is "interactive,ie the harder you drive the sooner the lights go out

[Guelphguy]

Ok...so who actually waits till the light tells you to change your oil??? I know I may be a little crazy, but I have always done Mobil1 oil changes every 5000km no matter what? It really does not cost that much more when you do it yourself, this is a 15 year old BMW so I would like to keep it running perfect as long as I can!

[mikell]

Nah, never wait for the lights - regular changes based on miles - Mobil 1 at 4500 miles.

[Bill R.]

96 have....



Principle of Operation








The Service Interval Indicator consists of






a row of LEDs and two text messages


displaying:


“OIL SERVICE” or “INSPECTION”. The LEDs show the length of time remaining until an


Oil service or Inspection is due. The SIA II display uses 5 green LEDs, one yellow and one


red LED.


The Display LEDs are only illuminated when the ignition is first switched on. The display


remains for approximately eight seconds before being switched off. The countdown to a


service on a new or recently serviced vehicle starts out with all green LEDs illuminated. Over


a period of time and mileage, the green LEDs will be turned off one by one . When a


service is due, all green LEDs will be out and the yellow LED will be illuminated along with


the text message “OIL SERVICE” or “INSPECTION”.


If the service is not performed the red LED will illuminate after an additional 1000 miles has


accumulated.


The calculation that the instrument cluster or IKE(E38) uses to calculate service interval is


based on three pieces of data:




• Engine Speed (RPM)








• Distance Traveled (miles accumulated)








• Engine Temperature








The use of Engine Temperature and RPM for the calculation allow for a more precise






estimation of when a service is required by taking driving styles into account. A vehicle for


example, that is driven aggressively or for short distances in stop and go traffic may require


servicing more often than a vehicle that is driven longer distances on freeways.



Edit to add a little more now that i've figure out how to copy from the clipboard....

Instrument Cluster with LED display.


The Instrument Cluster is responsible for calculating the Service Interval and displaying the


LED blocks used to represent time until next service.


DME


The DME control module provides the engine speed signal used in the SIA calculation.


Vehicle Speed Input


The vehicle speed input is provided directly by a reed switch in the differential


(E32,E34,E31,E36), or from a processed signal sent by the Braking and Traction (ABS/ASC)


control module (E38).


Engine Temperature Sensor


The engine temperature NTC sensor provides the engine temperature signal used in the SIA


calculation.













Kinda simple question, but what the oil service light bar on the dash base it's status on? I have driven 3800km since I reset it and changed the oil and it has not even gone down one green bar yet?

[Guelphguy]

Wow...thanks Bill R....I thought that BMW would have put more into it than just a standard count down....however I am still surprised how long it takes.....perhaps I change my oil too soon....or I guess there is no such a thing and changing oil too soon...other than the waste factor...

[Bill R.]

say to change... I personally change mine with synthetic mobil one 0w40 since its on bmw's longlife oil approval list , and i change it at between 5 and 7.5 k miles.
And actually thats all bmw needs to take into account, the engine temp reading would tell the dme if its short trips where the engine isn't fully warmed and the speed versus rpm would tell it if its mostly highway miles etc etc...





Wow...thanks Bill R....I thought that BMW would have put more into it than just a standard count down....however I am still surprised how long it takes.....perhaps I change my oil too soon....or I guess there is no such a thing and changing oil too soon...other than the waste factor...

[Paul in NZ]

i run castrol synthetic for the full interval,if was dino i would prolly change mid interval