How Chevy Corvette Oil Life Monitor Works

[qship1996]

Originally Posted By: Patman
Originally Posted By: BigCahuna
Has anyone changed their oil by the olm, then sent the oil for a uoa and had them say the oil still had lots of life left in it?.,,


I always wait for the OLM to hit zero when changing the oil and I always get UOAs done and every UOA has always shown that the oil had lots of life left in it. One time I even let the OLM count down to zero and I went an extra 2000 miles, for a total of 9000 miles, and it still showed life left in the oil.


If the above is true, then it also is true the oil life monitoring system is inaccurate.
"oil life readout is ZER0....oil showed to have a lot of life in it from the analysis"

 

[Quattro Pete]

Well, the OLM readings is not an exact science (and neither is a $20 oil analysis). If anything, I would guess the OLM errs on the safe side, for obvious reasons. It's still better than blindly recommend that the oil be changed every 3k miles or 3 months.

 

[Patman]

Originally Posted By: qship1996


If the above is true, then it also is true the oil life monitoring system is inaccurate.
"oil life readout is ZER0....oil showed to have a lot of life in it from the analysis"


It's not inaccurate at all, the engineers obviously built some leeway into the system as well, so that when the monitor does say zero your oil isn't completely spent. They eventually noticed that they built too much leeway into it, as the one thing GM did do on the Corvette after the first few years was change the algorithm so that the monitor counted down slower. For instance, on my 98 the maximum you expect to get out of the oil life monitor under ideal conditions is 10k. But from 2001 and up they changed that to 15k.

 

[JohnBrowning]

Years ago I posted some of the algorithm on this site for it. I was under the same contract as the lady that developed the prog bit of system. I cannot think of of her name now...Gray Hair glass's pulled back in a pony tail.....If you go into GM's Socrates PErsonel program and put in Olree's name she will pop up as being under him with Bob being an actual GM Employee and the lady that developed the algo's being a cantracted worker.... I ate lunch with her one day and she explained the entire mess.....Maybe it was not this site it might have been a COrvette site prior to me comeing to this site in 2003. Oh and yes I had permission at the time to post what I did and did so from a GM office computer.....

All OLM in GM use the same base programing with a few tweaks for each platform and engine combo.It is remarkable simple but since it does not track consumption and neede top off etc.....It can have it's limits!

 

[Spykem4e]

I only follow the OLM for my oil change and you can search in the UOA forum my 2005 CTS with great results between 10k-12k miles. I always trusted the OLM as long as there's no mechanical damages or rattle or any leak.

There is no exact sensor for the oil condition but I think GM OLM is one of the best system in the industry and its years and years of engineering and tests... If you want it to be accurate, you have to follow the owner's manual recommendations as for oil change, oil type and spec, maintenance etc. They also put a safety margin in the OLM.

I've used to OLM in all previous cars I've owned and never had an engine problem. I keep my car until 300,000kms and 350,000kms (4 years-6 years). The only problem I have is not in the engine or the transmission, its usually faulty coils, bad shocks, fuel line, rad...

 

[Loobed]

No oil composition sensors? No temperature sensors? No algorithm for highway miles being easier on the oil than around town miles? Etc.?


the engine has temp sensors. One for the block and one for the incoming air. If you have a Tech II sensor, you can see everything the computer sees.

There is an algorithm for highway miles. It's revolutions at specific engine temperatures.

I don't think they can make an affordable oil composition sensor.

 

[zulu]

Originally Posted By: JohnBrowning
Years ago I posted some of the algorithm on this site for it. I was under the same contract as the lady that developed the prog bit of system. I cannot think of of her name now...Gray Hair glass's pulled back in a pony tail.....If you go into GM's Socrates PErsonel program and put in Olree's name she will pop up as being under him with Bob being an actual GM Employee and the lady that developed the algo's being a cantracted worker.... I ate lunch with her one day and she explained the entire mess.....Maybe it was not this site it might have been a COrvette site prior to me comeing to this site in 2003. Oh and yes I had permission at the time to post what I did and did so from a GM office computer.....

All OLM in GM use the same base programing with a few tweaks for each platform and engine combo.It is remarkable simple but since it does not track consumption and neede top off etc.....It can have it's limits!


Shirley Schwartz

 

[mechtech2]

So what they ended up with is little more than what glovebox manuals have been recommending for decades - an oil life range from normal to severe service.
It is weak.
An oil monitor system should TEST the oil, or why bother . Failures of the coolant system, acid build up from a bad PCV system , metal particulate matter, etc., are some things that could be warned about.

 

[Durango]

In my newly bought 08' Impala SS I'm getting use to the new OLM that was built in to my system and love it!!!! I just make sure I use a good synthetic oil to go the distance or whatever the system say I can go. I'm old school as I use to have my oil changed every 3K no matter what under my normak driving habits.

The last time I have the oil changed was recently at 6K using the FF provided. I went ahead and put in the synthetic oil option at the dealership provided for an extra charge. Happy camper here!!!

The "OLM" itself I admit I took it slightly past 0% due to the holidays so how long the device will take me this time I guess I find out.

Durango

 

[dailydriver]

Originally Posted By: Patman
Originally Posted By: qship1996
That is no surprise,It is GM afterall. The system in no way is monitoring the oil itself, just the engine use.


The only car maker out there that I know of which has an actual sensor in the oil checking for contaminants is Mercedes, and I highly doubt that system is cheap either.

I'm so tired of people bashing GM around here, especially over something as trivial as an oil life monitor. The GM system might not actually test your oil for you, but it's good enough that it works. If GM started using that system that Mercedes uses they would have to raise the prices on their cars and then you GM bashers would whine about that. We just can't win with you guys.


EXACTLY Patman!!!
I knew when I clicked onto this thread it would not take long for the GM/domestic denigration to start.
Of course, every infallible <

Japanese, or other foreign manufacturer has a system even this good, right bashers/nipponphiles??!!

 

[Captain_Klink]

the FACT of the matter is: I bought a Chevy Venture with 140,000 miles of the clock, the oils were changed according to monitor, and the ENGINE WORKS PERFECTLY, it is quiet, smooth, there is no blowby at all. My son put on another 45,000 on it, and it still runs perfect, like just brand new off the assembly line. this is just a regular 3.4l 6 banger engine, hauling around an extended mini van.

I looked inside through the oil cap, and it is perfectly clean inside.

so the OLM works!!! very well, thank you.

i don't wait for the OLM to kick off, i change it with 20% left.

 

[qship1996]

If it works very well, why do you change your oil when it says 20% left???..... Did you even READ what you wrote????? In reality, it says you dont trust it any more than most people!!!!!

 

[Jaymus]

My mom has a 2000 Trans Am WS.6. It doesn't have a digital OLM that shows a percentage, but it does have a "Change Oil Light" that pops up usually around 4500 miles. It starts out coming on in the mornings and going off after about 5 minutes, until after another week or three, it finally just stays on.

This OLM can't make up its mind. And I run GC 0W-30 in this LS1, and I know the OLM doesn't take that into effect, but I know 4500 miles is nothing to GC in this feather throttled 80% highway car. Seriously, she drives it way too easy. I'm surprised the change oil light even comes on at 4500 miles with her highway driving and low RPM usage (6-speed auto).

It does have 188,4xx miles, though. I wonder if the OLM has any sort of engine mileage that goes into the algorithm/formula. Guess not if the article didn't mention it.

 

[Jaymus]

And not to bump this, I can't edit, but I also should mention... these cars call for Mobil1 from the factory. So, I'm sure it's already assuming it has a quality oil in the 6 quart sump, I just wonder why it thinks it needs an oil change at 4500-5000 miles with so much highway driving and extremely easy driving.

 

[Corvette Owner]

Originally Posted By: Jaymus
My mom has a 2000 Trans Am WS.6. It doesn't have a digital OLM that shows a percentage, but it does have a "Change Oil Light" that pops up usually around 4500 miles. It starts out coming on in the mornings and going off after about 5 minutes, until after another week or three, it finally just stays on.

This OLM can't make up its mind. And I run GC 0W-30 in this LS1, and I know the OLM doesn't take that into effect, but I know 4500 miles is nothing to GC in this feather throttled 80% highway car. Seriously, she drives it way too easy. I'm surprised the change oil light even comes on at 4500 miles with her highway driving and low RPM usage (6-speed auto).

It does have 188,4xx miles, though. I wonder if the OLM has any sort of engine mileage that goes into the algorithm/formula. Guess not if the article didn't mention it.


I don't think the Trans Am came with synthetic oil from the factory, so I think the OLM is calibrated for Dino Oil.

Did a 2000 Trans AM come with a 6 speed AUTO Transmission? I thought the first 6 speed GM AUTO transmissions came out in 2005?

 

[ARB1977]

I dont think i could trust anything like that. RPM's and load are the main points of the sytem....but what happens if you have a worn out engine that still runs. Is the system going to tell you to change the oil sooner? Thats why i would trust a uoa.

 

[GMBoy]

Good post, but dated information. The OLM has been revised several times since 2003. The OLM programming does take into effect things such as ambient temps and coolant temps so if you overheat or run hot and you're in the hot summer - more "perecent" of oil life will be used. My GM powertrain rep explained the system to me in great detail and while no olm can tell the actual condition of the oil (like if there is grit in the oil) these programs do a really good job at figuring it out. You can trust them for the most part but I myself do get a little weazy when the miles start to pass 7500. If you live in dusty areas I would not go by the OLM since it can't detect dust/dirt in the oil.

 

[GMBoy]

Originally Posted By: Corvette Owner
Originally Posted By: Jaymus
My mom has a 2000 Trans Am WS.6. It doesn't have a digital OLM that shows a percentage, but it does have a "Change Oil Light" that pops up usually around 4500 miles. It starts out coming on in the mornings and going off after about 5 minutes, until after another week or three, it finally just stays on.

This OLM can't make up its mind. And I run GC 0W-30 in this LS1, and I know the OLM doesn't take that into effect, but I know 4500 miles is nothing to GC in this feather throttled 80% highway car. Seriously, she drives it way too easy. I'm surprised the change oil light even comes on at 4500 miles with her highway driving and low RPM usage (6-speed auto).

It does have 188,4xx miles, though. I wonder if the OLM has any sort of engine mileage that goes into the algorithm/formula. Guess not if the article didn't mention it.


I don't think the Trans Am came with synthetic oil from the factory, so I think the OLM is calibrated for Dino Oil.

Did a 2000 Trans AM come with a 6 speed AUTO Transmission? I thought the first 6 speed GM AUTO transmissions came out in 2005?



Trans Ams had a 4spd auto and no Mobil 1 as Factory fill.

 

[Gary Allan]

I find the OLM a wonder of the modern world. ..but we live in a society where the individual resists two things.

Being told what to do ...and consulting the instructions before all else fails.

 

[Rickey]

Originally Posted By: mechtech2
So what they ended up with is little more than what glovebox manuals have been recommending for decades - an oil life range from normal to severe service.
It is weak.
An oil monitor system should TEST the oil, or why bother . Failures of the coolant system, acid build up from a bad PCV system , metal particulate matter, etc., are some things that could be warned about.


mechtech2:

You are so full of "feldercarb". (Battlestar Galactica)

The vehicles that do analysis on the oil measure so few parameters that they are vastly inferior to the GM OLM.

Are you really a tech sir or just a poser ?????

Mods this is a fair question considering the lack of logic contained in the post.

A responsible vehicle operator will hear the knock, monitor the coolant loss, see the sludge in the oil cap, etc.

If something is broke no oil monitoring system will be valid. !!

Even an UOA will offer challenges in the analysis process.

Rickey.