Silverado oil life monitor

**bd2200** · 09-03-2007, 06:29 PM

I bought a 05 Silverado a few monthe ago. It has been at least 7k miles since the last oil change and I still haven't gotten the "change oil soon" message . The dealer said to just check the oil level and to wait until the message appears before it needs to be changed.
Can this be right? What if the sensor failed?

**MD4x4 Fireman** · 09-03-2007, 07:46 PM

Originally Posted by bd2200

I bought a 05 Silverado a few monthe ago. It has been at least 7k miles since the last oil change and I still haven't gotten the "change oil soon" message . The dealer said to just check the oil level and to wait until the message appears before it needs to be changed.
Can this be right? What if the sensor failed?

repost this in the powertrain issues area and people will probanly answer quicker

**Steve** · 09-03-2007, 10:38 PM

I moved it here. This happens to be my brother out in Florida, so I'll cut him some slack for posting in the general room.

The Chevy Oil Life Monitor (OLM) will let you know when it needs the oil changed. Do you have the Driver Information Center (DIC) on that '05? It should have a series of buttons that will change the display in the same area where the odometer/trip meter is located at.

It's also possible that some type of synthetic oil was put into the engine, thus not showing the same breakdown as traditional oil would show.

**Crawdaddy** · 09-03-2007, 10:55 PM

I know with my saturn, there is no actual sensors to determine viscosity, breakdown, etc of oil. All it does is take your driving syle and conditions (drive it hard, ease on it, high strain, etc) and does some calculations to determine when it's time to change the oil. It's weird, and I've never had it tell me it's time to change the oil, but I do change the oil every 3000 miles regardless.

**Steve** · 09-03-2007, 11:19 PM

I found GM fact sheet on this.

The oil-life monitoring technology involves computerized monitoring of engine revolutions, operating temperature and other factors to determine when a vehicle's oil should be changed. Rather than depending on fixed oil change schedules that may not be suitable for all situations, the monitoring system customizes oil change schedules based on a vehicle's engine and transmission type and an individual's driving habits.

"Every driver operates with different driving styles and under different conditions," said Bagnall. "The GM Oil-Life System compensates for that, allowing a customized diagnosis of each vehicle's oil change needs."

When the system senses that the oil in a vehicle is nearing the end of its useful life, it notifies the driver that an oil change is needed with a "change oil" dashboard message that's displayed for 15 seconds when the engine is started. Once an oil change is completed, the oil-life monitoring system can be reset to begin a new analysis cycle.

This method of determining oil change schedules is more precise than the traditional approach of basing the cycle on the number of kilometres (or miles) driven -- typically 5,000 kilometres (3,000 miles).

**jdchet** · 01-12-2008, 08:33 AM

I know this is an old thread, but I'd bet that the formula for figuring out oil life is a lot simpler than it sounds!

Fuel used!

That will take into account highway or city driving, towing, heavy or light loads, etc.

My 2 cents.

JD

**Crawdaddy** · 01-12-2008, 09:10 AM

I don't know if it's THAT simple, but it could be a farily simple equation. I'd imagine it's take in factors like:

fuel used-only really gives an idea of driving habits, not realy oil breakdown
RPM-gives a little more insight into fuel used...
Water temp- if the block's hot, the oil's probably hot which leads to oil breakdown
Oil Pressure- oil that's been broken down is more likeley thinner leading to low oil pressure

I would think that a combination of those could create an effective equation to determine how good the oil is.