How Critical to change oil when change indicator light comes on

[alrich]

Hi,
My wife has a 2004 Ion 2. The indicator light indicating oil needed changing came on last week. I changed the oil this weekend after she put on an estimated 300 miles on it since light came on. The manual says get it changed by 600 miles. I use amsoil 7500 mile/6mo. 5w-30 oil. (7,800 miles this oil change 5 months) I am curious how the car determines when that oil light comes on? Does anybody know how the computer calculates when to turn it on and how critical is it to change it immediately when light comes on.
Thanks,
Al
Charlotte, N.C.

[fdryer]

If I may, the Oil Life Monitor (OLM) will undergo many calculations to determine when your engine needs its oil replaced. The Oil Nanny is a very good forgot-when-you-changed-oil-last to simply light up the next time the engine needs an oil change. I'm not that smart yet when I totally forgot what the OLM was when it turned on. I mistook it for the wrench indicator and dreaded the next few days agonizing over how I had to bring the car in to Saturn for diagnosis when I turned to my owner's manual; the nut behind the wheel (me ) didn't remember where the wrench or the OLM indicator was located. I sighed a big sigh of relief when I realized my Oil Nanny was reminding me to change the oil.

Its not mandatory to change the oil asap but recommended to replace it at your earliest convenience, whenever you feel is your earliest convenience so long as its done. There are many lengthy explanations but the easiest is the GM explanation. Some have posted the text but it may be easier to simply Google 'oil life monitor' for the GM descripton.

[DukeCitySC2]

It uses engine temp vs time (like short trips vs long), mileage, all the things that we've had drilled into us over the years about the need for oil changes. Lots of short trips where the engine doesn't warm up fully will shorten the interval, lots of highway time extends it. As far as I know it doesn't use a calendar, i.e., if you only put on 1,000 miles in a year I don't think it will say it needs a change based only on time.

[2006 ion2]

it doesn't mind time for you, GM says no more than a year

[Audi Junkie]

Send a sample to Blackstone Labs for a Used Oil Analysis to look at wear metals from the various parts of the engine's metalurgy and a TBN test to see how much the oil lost it's ability to neutralize acids. An elemental UOA also gives a peek into the oil's additive composion and amounts. Well worth the $25 bucks. Ask them to send a free sample kit to you.

Basicly, the OLM is calibrated for dino oil, but you are using a premium synth oil (AMSoil XL line?). A lot of short trips will ding the OLM a lot, you could probally reset it and go a 2nd run until you drain the AMSoil. Back that up with a UOA or just use dino and run the OLM once a drain.

[bigbird]

I ignore the OLM entirely. I never exceed the mileage requirements for an oil change, so I go strictly on time. If I didn't change my oil and filter every 3 months in the winter and 4-5 months in the summer I would be doing my engine an injustice. I don't care if it's synthetic, semi-synthetic, or just plain regular engine oil. The OLM is there for the people who are maintenance challenged.

[lgodave]

bigbird,

I'm a bit surprised by your disregard for the OLM. It isn't a "dummy" feature... it does actually do some calculating when to change your Oil. It doesn't check your level (so keep an eye on that) or consider "outside" factors so if your vehicle's engine spent time under water or someone dumped Washer fluid or Anti-Freeze in the Engine (stupid mechanics) you'd be in trouble.

If like Audi Junkie suggested... you have an Oil sample tested after 3/4/5 months... you might find that the Oil's condition (and the Engine) are both in good condition and could continue service for maybe a month or more (depending on the results) before draining.

Cool thing with the ION is how easy it is to replace the Oil Filter. Some may find that by just replacing the Filter... you might extend the service life of the Oil.

My 2003 ION has a 6 month/6,000 mile change interval (doesn't consider the OLM) so I've tended to stay within that time frame. My Test samples sent to Blackstone Labs have suggested my Synthetic Oil(s) can exceed that interval.

I've usually stuck with maybe 3 Oil Changes a year so that I stay on top of any other Maintenance and PM concerns.

[jonny772]

The one time I noticed the oil life indicator I had just gone over my usual oil change mileage, so it was due either way.

[lgodave]

jonny772 makes a good point...

Everyone's OLM vs REAL Change Interval vs Actual Oil Life will be different... but for some (My Mom's 05 Equinox) the OLM/Change Interval/Oil Life each seem to nicely balanced so that if she changes according to the OLM, oil tests suggests she is right on target with changing the Oil as needed.

So if she "forgets" the interval (Currently about every 6,000 miles) the OLM (Onstar also reports OLM % each month) has been fairly consistent in requesting a change around that time.

[JH6]

For what oil costs, I just ignore the OLM in my 03 ion. I reset it way before it needs to be..

I change with good regular quaker state every 4k-4500k miles, and a new filter.

Motor looks as clean as day one.

Not bad for 10 dollars in oil, and a 5 dollar filter.

[2006 ion2]

the fact remains frequent oil changes are only good for wasting oil, nothing else. oil analysis proves this, and if engines were better protected against dirt and water getting into the oil, oil changes would be even less frequent.

[BrianION3]

I ignore the OLM. My 2006 Ion 3 has 105K miles on it, and I change the oil about every 6 weeks or so. I drive about 1K miles a week, mostly highway. I enjoy doing it myself and I look forward to the Saturday oil changes, in my garage with the stereo cranked up and a few bottles of cold beer/pop in my dirty hands.

Sometimes I go crazy and change the oil in all three vehicles...now that's my idea of a great Saturday morning. I was going to do the front brakes last weekend, really looking forward to it, but when I pulled the wheels off I saw there was no need to yet.

I can spend hours working on my vehicles, or just detailing them, as long as the music is good and the beverages are handy and plentiful.

If you need more than 20 minutes to change your ION oil, you're doing something wrong though.

[2006 ion2]

wow, 1K a week? keep in mind, your OLM is your friend and it won't steer you wrong, if you doubt it, let it go once and get that oil analyzed professionally, it's cheap and they get payed to tell you the facts they can determine by their tests. in the over 200K miles you have left in your ion, it will show some real savings.

[lgodave]

Originally Posted by 2006 ion2

wow, 1K a week? keep in mind, your OLM is your friend and it won't steer you wrong, if you doubt it, let it go once and get that oil analyzed professionally, it's cheap and they get payed to tell you the facts they can determine by their tests. in the over 200K miles you have left in your ion, it will show some real savings.

I agree. Let the OLM "run out" and see if it agrees with your change interval.

If you have a set change schedule... you could keep it or find you have the option to extend it a bit longer. It might not be as much fun, but you could also try dropping in a fresh oil filter if you simply MUST do something to your vehicle(s) every 6 weeks. More time listening to music, drinking, and detailing that stubborn spot right behind the wheel(s).

RE: Letting the OLM "run out".

I didn't change my Oil at the end of August at my suggested 6,000/6month interval and the Change Oil Warning kicked in about 40 miles ago. I'll probably stop at Saturn in the next two days and get the tires rotated (free tire care) and use my free oil change card.

Kicking back with some fresh baked cookies and a cold can of juice/milk/soda might be just the trick.

[RoadIon]

What ever you want to go by, OLM or miles. Don't be lazy change your oil and filter.

[chilipepper1327]

First of all, KNOW YOUR CAR! That means your car, your driving habits, your oil type/brand etc.
Read the owners manual.
I typically change my oil when it is on the "add" portion of the dipstick as I do drive hard. This is normal.
I use synthetics and change the oil on the second time around on the OLM, but I usually don't get that far like I mentioned. Oil and coolant maintenance is the single most important upkeep for your car. In Canada, when I have to have a smog test done, the mechs are always surprised to see that my 04 Ion with 115,000 miles is better than new (not too surprising if you understand why, on average, this is so. All about breaking in the engine).
Do what you feel best and if that means going by the recommended milage, then do so. Just remember to reset the OLM after each change. Just push the button until you see the oil indicator, hold it in when you get there until it resets