How do OLM (oil life monitors) work?

[PICK3]

Do they measure viscosity?

 

[JarheadChiro]

How Oil Life Monitor System Works

Engine oil forms a coating on the moving parts of the vehicle's engine to protect against friction and heat damage related to combustion. But over time, that protection can be damaged by several factors. High operating temperatures can cause oxidation while cold engine operation introduces contamination to the oil.

GM engineers have been studying oil life for decades and they've learned that oil tends to degrade in a predictable pattern.

Taking many short trips is more harmful to the oil than highway driving, because it tends to introduce moisture when the engine doesn't reach full operating temperature before being shut off. Heavy use like trailer towing or prolonged driving in very hot conditions can lead to a thickening of the oil that prevents it from adequately coating engine parts.

GM engineers took this knowledge of operating parameters and oil life and built a mathematical model that is run by the car's powertrain control computer. The Oil Life System monitors engine temperature, combustion events and other parameters to gauge the oil's life.

 

[PICK3]

How Oil Life Monitor System Works

Engine oil forms a coating on the moving parts of the vehicle's engine to protect against friction and heat damage related to combustion. But over time, that protection can be damaged by several factors. High operating temperatures can cause oxidation while cold engine operation introduces contamination to the oil.

GM engineers have been studying oil life for decades and they've learned that oil tends to degrade in a predictable pattern.

Taking many short trips is more harmful to the oil than highway driving, because it tends to introduce moisture when the engine doesn't reach full operating temperature before being shut off. Heavy use like trailer towing or prolonged driving in very hot conditions can lead to a thickening of the oil that prevents it from adequately coating engine parts.

GM engineers took this knowledge of operating parameters and oil life and built a mathematical model that is run by the car's powertrain control computer. The Oil Life System monitors engine temperature, combustion events and other parameters to gauge the oil's life.

thanks for the info

Wished I would have included in my topic "and do you rely on them?"

 

[Mr. dB]

The GM system is pretty lame then. The Bosch system used in Mercedes and BMW cars includes a sensor in the engine block that actually measures "something" in the oil. What that something is, I'm not exactly sure, but it would have to be either viscosity (hard to measure) or metal particles suspended in the oil.

 

[JarheadChiro]

I agree that the GM system is lame...

The most accurate way to measure oil life would be through photospectrometry, looking for a certain # of suspended solids, which would cause added friction.

My Dad, who was a QC guy making motors his entire life says that oil filter changes are more important, than swapping the oil.

I argued the HEPA issue with him...

 

[PICK3]

I agree that the GM system is lame...

The most accurate way to measure oil life would be through photospectrometry, looking for a certain # of suspended solids, which would cause added friction.

My Dad, who was a QC guy making motors his entire life says that oil filter changes are more important, than swapping the oil.

I argued the HEPA issue with him...

That's surprising ... I heard oil filters actually do little filtering.

 

[Mr. dB]

thanks for the info

Wished I would have included in my topic "and do you rely on them?"

Cars using the Bosch system and synthetic oil often go 10K+ miles between changes.

 

[PICK3]

Cars using the Bosch system and synthetic oil often go 10K+ miles between changes.

They recommend 10k oil changes on new hondas with regular (dino) oil.