I'm a GM oil life monitor believer

Messages
217
Location
NC
We have been using the GM OLM exclusively in dad's silverado with the 5.3 ecotec3. It seems to be working pretty well. I know the GM OLM is supposed to be fairly intelligent but it so far tracks closely with 7500mi intervals. The one occasion we used M1 EP in the truck it was not convenient to change at 7500 so we reset and went again to about 50%. Everything still clean and nice looking approaching 90k.

We did do a UOA on a full OLM run of Magnatec. It didn't turn up anything out of the ordinary and the TBN was 2.2.
 
Messages
801
Location
Alaska and Wisconsin
GM recalibrated the OLM on my 2012 Equinox 2.4. I don't remember exactly but you could tell the oil life went down way faster.
On my 2013 Nox with the 2.4L, I change it before it reaches the 50% point. That's around 3,000 to 3,500 miles using DEXOS oils like QSUD, Kirkland, and Magnatec during summers.

Maybe it's just me, but I believe GM's OLMs run too long. Your experience with GM bears that out. Thanks for the confirmation.
 
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Messages
35,696
Location
NY
I followed the OLM religiously until I found out they recalibrated for 7500 max interval. My sisters 2012 Cruze used to routinely go out to 9k or so. Since the recalibration in 2013 to max out at 7500 (her car has never been recalibrated) I do it with 25% remaining. Has 150k on it. Part of the issue might have been that back in those days ACDelco Dexos was a syn blend. I’ve always used Mobil 1, so maybe that saved things (little Turbo 1.4). With the DI 1.5 start/stop in my new Equinox I’m inclined to do 5000-6000 max. Basically, once the OLM were found to be trashing some engines I lost trust.
I agree with you. I've written about my OLM a few times, and why I've ignored them since day one. This is one of my fears, unfortunately there is no way of reversing any damage which may have been caused by on overly optimistic OLM. IMO the best way to determine an OCI is with a severe service interval with a UOA when you change the oil. Then determine an OCI based on data and common sense. As far as I'm concerned an OLM is a conversation piece which I ignore.
 
Messages
8,590
Location
Texas
The worst thing to come out of OLM systems is the stupidity of the general public. I cannot tell you how many times (hundreds!) I've had to teach people that the OLM is just predicted oil condition - NOT oil level. I have many times found a car 1 or 2 qts low and when I ask why they are not checking the oil they say" well it says I am at 40% so I am good"! People really don't check their oil levels and drive these cars 5,6,7,8k miles or so and by the time they get to the oil change - they are very low on oil. Then the cycle repeats. I have gotten cars with 7k miles and maybe 2qts in the sump drain out. The worst cars to run to the OLM and not check your level are the GM 3.6L and ecotecs......but almost any car will use some oil at these longer drain intervals. Not to mention cars requiring syn or Dexos and they run a cheaper oil that the OLM does not take into account because it does not know - they possibly just went too long on a change.

Sorry for the ramble guys - just gets me going when people don't know what the OLM is for.
 
Messages
571
Location
Washington, DC
The worst thing to come out of OLM systems is the stupidity of the general public. I cannot tell you how many times (hundreds!) I've had to teach people that the OLM is just predicted oil condition - NOT oil level. I have many times found a car 1 or 2 qts low and when I ask why they are not checking the oil they say" well it says I am at 40% so I am good"! People really don't check their oil levels and drive these cars 5,6,7,8k miles or so and by the time they get to the oil change - they are very low on oil. Then the cycle repeats. I have gotten cars with 7k miles and maybe 2qts in the sump drain out. The worst cars to run to the OLM and not check your level are the GM 3.6L and ecotecs......but almost any car will use some oil at these longer drain intervals. Not to mention cars requiring syn or Dexos and they run a cheaper oil that the OLM does not take into account because it does not know - they possibly just went too long on a change.

Sorry for the ramble guys - just gets me going when people don't know what the OLM is for.
My understanding of things is that this is one of the reasons why the sump size increased from 6 to 8 qts for the latest gen GM truck engines, specifically to get some safety margin for oil loss.
 
Messages
1,935
Location
Northeast Nebraska
On my 08 Lucerne I'm right at 5 months and 1000 miles and the OLM says 78%. Mine has the 3800 in it. I plan on going a year but we'll see how the OLM handles the winter.
Glad this thread came up again. Six months and about 1200 miles later my OLM says 50% now which makes a total of 2200 miles on this OC, this tells me if I took it to 0% it would be right close to 4400 miles. First 5 months was summer and it dropped 22%, next six months included winter with a lot of morning starts to warm up cabin and it dropped 28% so it did take into account the idle times and cold weather.
 
Messages
7,061
Location
Wet side WA
I believe that the GM oil life monitor runs out in one year if you don't turn the car over. Point in case my Duramax. Reset the monitor at one year because it said it was at 100%. Dove it another six months until we had better weather and no rain. Left the filter on it only had 982 miles of use.
 
Messages
805
Location
GA
I had an '07 GM that would go 12k+ before the oil change light came on. About half and half highway/rush hour stop and go. I'm gonna stick with 5-7k.
 
Messages
856
Location
Daytona Beach
There are OLMs, and there's the GMOLM. Some are simple timers, others are simple mile counters, neither one of those types bases an oil change interval on how YOU actually drive YOUR car. The GM OLM was invented to avoid unnecessary oil changes in an effort to protect the environment and become more environmentally responsible. Yes, it was a THING even back in 1999. They KNEW that everyone's driving situation is different, and came up with a way to take those differences into account.
So, maybe there was an issue with timing chains on some cars, it may have even been because of the supplier, but at least GM provided a "FIX" that wouldn't require re-writing all of the owners manuals and re-training all the owners to follow the new guidelines.
Some people will never understand an olm, and there are others that will never understand an owners manual. When the manual says to change the oil once a year or 7500 miles, why would the OLM NOT count down to zero when those conditions are exceeded?
There are also people that see Dexcool lifetime antifreeze, and totally ignore the 5 year or 150,000 mile change interval.
 

Corollaman

Thread starter
Messages
550
Location
Eastern Wa.
I'm the original poster, can't believe this thread got dug up. Anyways my 2011 Silverado reads 92% oil life left and I've driven about 350 miles on this oil change. I can get 3,500 to 4,000 miles or 10 months before I get an oil change signal. 90% of my driving is short trip so based on that I do believe in the system. I'm using regular 5w30 maxlife, it's not dexos. I have the old 4.3 v6. I've got 19,500 original miles.
 
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