PPV and SSV - AFM and DFM

[Dropfire93x]

I wasn’t really sure where exactly to post this. MODS, please move to the appropriate place if needed.

The other day I was sitting down talking with our Fleet Manager about our history with Tahoe PPV and SSV models, dating back to 2012. About 90% have been the PPV 2WD models with the remaining being either PPV 4WD or SSV models. Most are used for Police Uniform Patrol and are treated like the usual patrol vehicle. With the exception of a few (right or wrong), the oil change intervals are based on each vehicle’s oil life monitoring system. During the discussion, we could only identify one vehicle that has ever experienced lifter failure and it was a 2017 PPV 4WD assigned to the Fire Department. That vehicle was definitely not used as hard as the police SUVs and went down in late 2021.

I’m not trying to minimize anyone’s negative experience from lifter failure nor wanting to start another debate about AFM and DFM. There are plenty of threads about all of that. I just wanted to share what our history has been with these vehicles. Overall, the Tahoes have served well and have been reliable vehicles, even when treated a little rough.

 

[CMoore711]

Since you were using each vehicle's oil life monitoring system I'm assuming you were going off of the oil life %? Based on that was there a specific "rule of thumb" oil life % that you would then typically change the oil? ie. We always changed the oil when the oil life got down to 15%.

 

[Dropfire93x]

Since you were using each vehicle's oil life monitoring system I'm assuming you were going off of the oil life %? Based on that was there a specific "rule of thumb" oil life % that you would then typically change the oil? ie. We always changed the oil when the oil life got down to 15%.

 

[Dropfire93x]

That was the general plan. Usually how it works is when the message “change oil soon” was displayed, it was a simple matter of getting into the Maintenance Shop for a PM. As a back up plan in case someone would ignore the Oil Life Monitoring System, the Shop Supervisor tracked each vehicle’s maintenance and would “politely“ let folks know it was time to bring their vehicle in.

A few of us “kind of” handled our vehicle’s basic PM on our own. I would use the facilities in the Maintenance Shop and change the oil every 5,000 miles. No one cared since it was being taken care of, especially the Shop Techs. I try to take good care of my personal and work vehicles.

 

[2015TahoePPV]

My 2015 has 174K on it now (I bought it with 120-something) and I’m not having any indication that the AFM system is in distress. I can feel it engage/ disengage on the highway. I don’t think I’d spend the money to tear into this engine to replace them, I’d probably build up a lower mile unit and swap it in if something catastrophic happens. I had to ditch my “plug in” afm delete when I updated the stereo (it needed an OBD connection)

 

[Marky Dissod]

The other day I was sitting down talking with our Fleet Manager about our history with Tahoe PPV and SSV models, dating back to 2012.
About 90% have been the PPV 2WD models with the remaining being either PPV 4WD or SSV models.
Most are used for Police Uniform Patrol and are treated like the usual patrol vehicle.
With the exception of a few (right or wrong), the oil change intervals are based on each vehicle’s oil life monitoring system.

During the discussion, we could only identify one vehicle that has ever experienced lifter failure:
a 2017 PPV 4WD assigned to the Fire Department.
That vehicle was definitely not used as hard as the police SUVs and went down in late 2021.

I’m not trying to minimize anyone’s negative experience from lifter failure nor wanting to start another debate about AFM and DFM.
There are plenty of threads about all of that. I just wanted to share what our history has been with these vehicles.
Overall, the Tahoes have served well and have been reliable vehicles, even when treated a little rough.

So, the one engine that likely spent more time half@$$ing itself vs the others, is the one that experienced lifter failure?

 

[Dropfire93x]

So, the one engine that likely spent more time half@$$ing itself vs the others, is the one that experienced lifter failure?

If I understand your question, yes one of the Tahoes that did not experience heavy duty use had the lifter failure.

 

[Marky Dissod]

You understood my question well, but allow me to paraphrase another way.
The engine that
... spent more time half@$$ing ...
... did NOT experience heavy duty use ...
... likely spent more time with more cylinders deactivated ...
experienced lifter failure.

If you cannot disable cylinder deactivation (you should), try driving so as to avoid using it.

 

[2015TahoePPV]

My 2015 has 174K on it now (I bought it with 120-something) and I’m not having any indication that the AFM system is in distress. I can feel it engage/ disengage on the highway. I don’t think I’d spend the money to tear into this engine to replace them, I’d probably build up a lower mile unit and swap it in if something catastrophic happens. I had to ditch my “plug in” afm delete when I updated the stereo (it needed an OBD connection)

Just to update this. Right after 190K, my Tahoe had a P0306 when I was driving to lunch, and an obvious misfire going on/ dead cylinder. My AFM system failed on the #6 intake valve, collapsed lifter. I’m in the process of replacing the engine with a reman.