Oil monitoring in newer vehicles

[Mark Christianson]

So how do these things really work??

The ole service guy at Gould Chev some time ago, told me that it monitors the condition of the oil to determine the percentage of life left.

OK, so if thats the case, when I change oil, why doesnt this super sofisticated sensor know that, and reset back to 100% on its own??? I have to go through the reset myself. That tells me it surely isnt monitoring the oil itself in any way.

Because I didnt really believe that theory/idea as to how its monitored, I asked elsewhere. I asked my private car mechanic. He said the meter monitors the engines "performance"; or how you drive the vehicle to report the oil life back to you based on how you drive the car/truck.

So if thats the case, how does it know if you use conventional oil, or if you have full synthetic in it?? It should be completely different in maintenance duration if you use synthetic oil versus conventional oil.

Inquiring minds want to know.

[jwhjr]

It doesn't know if you're using synthetic or conventional oil. It monitors temp/rpm etc. to determine the "life". I have the OLM system in my 04 Silverado, and I've noticed that during the colder months the percentage drops down much faster than the warmer ones. If you do a lot of short driving trips where the engine doesn't get up to temp it goes down faster vs. trips to the cabin where it maybe drops a percent in 400 miles. Because of the variability of how the percentage drops I have to believe there's some logic to it

[Mark Christianson]

That logic doesnt work though.

If you are using synthetic oil, you should be getting more mileage between changes. If the truck doesnt know what kind of oil you used, how can it properly tell you the life left?

So if you spend the big bucks on full synthetic oil, the truck is telling you its time to change it, but in reality you should still have at least double the time between changes in comparison to conventional oil.

[jwhjr]

I'm with you on that. It's not monitoring the condition of the oil itself, just estimating the "life" based on driving habits and conditions. From what I've read on it, it's based on conventional oil. I know some send their oil in for analysis after each oil change, so that would be a good way to determine how long to leave synthetic in. I've run synthetic in mine since 1500 miles, and for the first 50K I just changed it out based on mileage at around 5K. For the last 25K I've changed it out based on the OLM. It ends up being 7-8K in the warmer months, and 6-7K in the winter. Basically I've just eliminated 1 oil change a year for myself based on my average of about 15K a year that I drive. Even though I run synthetic and could probably go even longer between changes, I figure changing it twice a year isn't that bad.

[Mark Christianson]

Maybe I should read my manual. LOL

Thats kinda what I was thinking how this thing worked.

I like how the guy at the Chevy dealer told me flat out that it monitors the oil condition for you. I envisioned there was a little guy with a lab coat working under my hood or something.

[Jeremy airjer W]

They do not monitor the actual condition of the oil but make a hypothetical guess on the condition based on a handful of inputs. It has no idea what oil is used as far as synthetic or conventional. It doesn't care if its a quality oil or a no name brand. It doesn't know if there has been anything else added to the oil. It can not tell you if there is gas in the oil from it being flooded or from a fuel system leak. It cannot tell you if there is coolant in the oil from a leaking intake or head gasket. It can not tell you if the engine is as efficient as it once was or if it has a little more blow by.

Some of them have become quite sophisticated but in all actuality there are only as smart as the information they are given.

[Scott K]

Some of them have become quite sophisticated but in all actuality there are only as smart as the information they are given.

Exactly!! It is a program that just looks at some inputs and depending on the conditions, it maks the % drop quicker!

Just a friendly reminder, if you go off of the Oil monitoring system, check your oil regularly, smell it, and look what it looks like and feels like. Like Airjer said, it doesnt know if there is gas, antifreeze, water, dirt, or if it has been empty for 3000 miles! And use comon sense, if you have 10k on the oil change and it still says you have 60% remaining, its wrong!!

As for synthetic oil, manufacturere dont judge it by synthetic oil, because they judge it by the oil that they think is best for the engine, and they reccommend that. A good reason to follow your owners manual.

[Mark Christianson]

So basically the meters are a bunch of hooey?

Or I should say, they arent really doing you much good.

Interesting.

[Shack]

Most of them it just comes down to eng. run time and mileage.

The oil minder system gathers this data from the PCM and other systems on the vehicle and out puts it into percent of the dedicated service interval you have selected the oil minder system to monitor at.

Now, Chevy might have be a little more in-depth than this, or it just sounds like some miss information has been passed around the repair shops in Monti Town , like that old game telephone

Rule number 1# in the auto industry:

“If you do not know the answer, just make it sound good”

[Jeremy airjer W]

So basically the meters are a bunch of hooey?

Or I should say, they arent really doing you much good.

Interesting.

Think of it this way. You change your oil at home do you put a sticker in the window? You have the oil changed and they put a sticker in the window but it falls off or gets faded by the sun. Do you keep the receipt with the mileage in the car so you know when to change it?

The oil life monitor is more than a "monitor". It is more importantly a reminder of when service is due.

[JohnMickish]

If they didn't work why would the factory warranty your motor for the length of time that they do?

I was very reluctant to believe in these things when they came out, but after a few years and LOTS and LOTS (my wife and I put on about 45,000 miles a year) of miles with no problems I've come to believe in them.

Trust your electronics.

[jwhjr]

Trust your electronics.

Spoken like a true fisherman!

[Jeremy airjer W]

If they didn't work why would the factory warranty your motor for the length of time that they do?

I was very reluctant to believe in these things when they came out, but after a few years and LOTS and LOTS (my wife and I put on about 45,000 miles a year) of miles with no problems I've come to believe in them.

As long as we agree that they are only as good as there inputs and a little common sense has to be used as well (check oil, change oil after contamination, ETC.) than by all means use them and change the oil when it says so.

Its the common sense part that worries me about these systems. People assume that once the hood is closed after a service it is good to go until the next service. This could not be further from the truth. Maintaining/checking oil levels even with brand new vehicles is very important especially with the extended service intervals. It doesn't make a whole lot of sense to run around with a quart or two of oil in the pan for a couple thousand miles, yet I see it everyday with higher service intervals!!! If its a six quart system like the newer gm trucks, and GM says a quart every 2k miles is o.k., after 10k you could very well be at a quart. The monitor has no idea how much oil is in there its only been programmed based on 6 quarts. The 1 quart that is left is circulating through the system 5-6 time more than if there is 6 quarts, right? That can't be good!!!!

[nitroant]

For $20-$30 per oil change I just change my oil every 3,000 miles and to do it costs me $100-$150 a year in oil changes. Pretty cheap in my book. I would rather spend the money on an extra oil change or two a year and not worry. Just my .02

[Dozer]

Originally Posted By: mnfishinguy

If they didn't work why would the factory warranty your motor for the length of time that they do?

I was very reluctant to believe in these things when they came out, but after a few years and LOTS and LOTS (my wife and I put on about 45,000 miles a year) of miles with no problems I've come to believe in them.

As long as we agree that they are only as good as there inputs and a little common sense has to be used as well (check oil, change oil after contamination, ETC.) than by all means use them and change the oil when it says so.

Its the common sense part that worries me about these systems. People assume that once the hood is closed after a service it is good to go until the next service. This could not be further from the truth. Maintaining/checking oil levels even with brand new vehicles is very important especially with the extended service intervals. It doesn't make a whole lot of sense to run around with a quart or two of oil in the pan for a couple thousand miles, yet I see it everyday with higher service intervals!!! If its a six quart system like the newer gm trucks, and GM says a quart every 2k miles is o.k., after 10k you could very well be at a quart. The monitor has no idea how much oil is in there its only been programmed based on 6 quarts. The 1 quart that is left is circulating through the system 5-6 time more than if there is 6 quarts, right? That can't be good!!!!

My 00 Chevy also has a oil level sensor. If it is about 3/4 of a quart low the light comes on. I go by the oil life monitors on my stuff and run synthetic. On my 00 Chevy it will run 8500 miles on the highway without a trailer and Ive seen it run 3300 miles in the winter with a trailer most of the time. I have a 98 Grand Prix that also has a monitor, It will run about 7000 to 9000 miles depending on the time and the distance of the daily drives.

[Wildabeast]

For $20-$30 per oil change I just change my oil every 3,000 miles and to do it costs me $100-$150 a year in oil changes. Pretty cheap in my book. I would rather spend the money on an extra oil change or two a year and not worry. Just my .02

Well, with oil changes running me over $150 on my truck I'm not going to spend an extra $500 year by changing at 3K. I use oil analysis to be sure and can easily run 15K between changes (could do 25K, but I choose less).

[BoxMN]

Not to change subject or seem like I know anything... but I just can't see changing oil at 3k these days, with the oil itself being better, and the engines being better, than the they were in the old "oil change at 3k" days. I understand totally that the cost of oil is not a ton compared to the cost of rebuilt or new car, etc. But then why not 2000 miles? Why not change tires at 20,000 miles instead of when they are ready to be changed.

Maybe the oil change at 3k is more to do with making sure you check your oil level, as has been suggested. And then if you will add, might as well change it...?

My neighbor, waaay smarter than me when it comes to engines, still changes at 2-3k miles, but when I ask him WHY it is simply they way he has always done it. But my last two vehicles, sold one at 165k with strong engine, and current has 165k, I start to think about changing oil at 5k, and then make sure to change it around 7k. I do check level though before any trip.

I just inherited my Dad's 05 Trailblazer, first oil monitor vehicle I have had, and I think I will follow the monitor for the most part, keeping the stuff yous said in mind about type of driving. This was a good thread with good info on all sides. Thanks.

[Jeremy airjer W]

From a service end point of view customers would be seizing engines left and right if we went with longer service intervals. The average person does not understand that its there responsibility to keep it full after it leaves the shop. Guess who the first person there calling is when the oil light pops on after 3,000 miles! Not to mention they don't understand that oil is there for a reason, the only time they really understand what that reason is is when they get the estimat for a couple thousand to replace the motor!

I have several customers that wait until there "oil" light (not the maintenance light, the low oil pressure light) comes on before they make the appointment to have it changed!

[BoxMN]

Yeah, I understand that - make total sense. But I will stick with longer intervals for myself

[Scott K]

I will go anywhere from 2-5k on my oil change, depending on how it was driven in those miles. If I drove it non loaded, or not pulling anything to the cabin 5 times, and I put 3k on in a month, I will go 5k. If I pull my 28ft enclosed trailer to the cabin 4 times in a month, I will change it at 2k! I check the fluids regularly, ck tire pressures, ect.. I know oil is better quality today then it was in the 80's, but that is why you are seeing 200-300k on the engines, if you take advantage of the better quality oil you may only get 150k, or less!

If you are one who doesnt check your oil at all, you may run out of oil at 7k, and be putting in an engine, rather then spending $25 for an oil change. The average person out there doesnt even open their hood, ever! If shops started writing oil change stickers for service at 7500 miles how many engines do you think they would be replacing?

[Iron Cowboy]

I was listening to Paul Brands "auto talk" and a similar conversation of oil life came up. He had a few calls of guys with 200k + in miles on original engines that had the oil changed only a few times. every 50k or so. said oil doesnt wear out it just gets dirty and to go by the color, frequent changes are more to make the owner happy cause thats how his dad taught him to do it. change intervals are just a money maker for the oil corp. Said in the big rigs its cheaper to do an oil lab test of life left and they will go over 100k without changing.

I dont go that long but with adding a quart every 5k to my car I go 15k with mobile 1 gold cap befor a change like the bottle calls for. 200k plus on my accord without any issues and It gets abused daily. Anybody ever have a mechanical failure that was officially diagnosed as "oil life related" ?? I'm not saying it doesnt happen I've just never had one or heard of anyone that has.

[Jeremy airjer W]

I know for a fact that Honda/acura will not make it much further than 80k between oil changes. I know that older park avenues could make it about 30 to 40k before giving up.

Toyota found out the hard way that an extended service life of 7,500 miles was not ideal for there early v-6 in the Camry. They replaced a lot of engines due to sludging. They have gone back to 5k on all models. I for one am not willing to be the guinea pig to find out how long I can go or what the end result of the added miles between service will have!

[Shack]

Quote:

I was listening to Paul Brands "auto talk" and a similar conversation of oil life came up. He had a few calls of guys with 200k + in miles on original engines that had the oil changed only a few times.

Ya, I have heard those guys call into Paul B and Joe S. All I say is "what ever floats your boat ".

I never argued with any customer about how they took care of their car. Let's face it, they where my bread and butter .

[JohnMickish]

Airjer, you forget that when the 3000 mile "standard" came about vehicles where carbureted (yes, cars and trucks had carburators at one time) and ran at a much richer mixture than they do now. The chokes where never set right and they would wash the rings down with gas, diluting the oil. Air cleaner assemblies where not sealed good agains the carb neck either.

Todays vehicles run at such a cleaner standard than they did just 15 years ago that changing oil at 3000 isn't needed, but it's not going to do any harm either. Follow what the owners manual says and your vehicle will last longer than you want it to.

Peace of mind is another thing to consider as well. IMO, it's like buying an extended warranty. If you feel better doing it then do it.

[Jeremy airjer W]

True but we also must remember that we live in the land of extremes! Until your vehicle warms up it is running on a programed strategy that although entirely more efficient than the days of the carburator still is not as efficient as its warm running strategy. I do agree that engines do run more efficiently and are generally much cleaner running but even that can be argued with some manufactures choices of engine design.

A perfect example came in tonight. An 05 Buick Terraza came in for service based on its service reminder. At a little over 8,000 miles and guess what about a quart and a half came out! That just isn't good and shows the lack of education on how service intervals are supposed to work!