How to completely disable cylinder deactivation?

[N7turbo]

The problems that come from cylinder deactivation come from the design of the cylinder head and torque converter to accommodate it, not from the activation of the feature while driving. I doubt deactivating it will accomplish anything, but you're free to try and report back.

 

[Mulligan]

The problems that come from cylinder deactivation come from the design of the cylinder head and torque converter to accommodate it, not from the activation of the feature while driving.

That's probably right.

However, the temperature difference between active and deactivated cylinders likely adds stress to the head. That extra stress acting on the poorly designed (or poorly manufactured) cylinder head could be the straw that breaks the camel's back and results in a crack. If that's the case, disabling cylinder deactivation could reduce the likelihood of head failure.

Speculative, but not irrational.

I can't blame anyone for wanting to disable their cylinder deactivation on the chance there's something to the heat/stress hypothesis.

 

[walt]

But why? What is the benefit?

They were failing and causing a rattle that required head replacement if I recall.

 

[N7turbo]

The engine failure is a crack leading to an oil leak.

The transmission issue is wearing of the clutch material contaminating the fluid as previously mentioned in the thread.

 

[Mulligan]

They were failing and causing a rattle that required head replacement if I recall.

You're probably recalling a ticking problem that affected 2018 to 2021 (at least) models and was attributed to faulty hydraulic lash adjusters (HLA). There were some technical service bulletins about it, e.g., Bulletin 01-022/21 "TAPPING NOISE FROM ENGINE."

Repair recommendations started with "Hold the engine rpm between 2500-3000 for 5 min, then idle for 5 min. Repeat this 2 times." If that didn't work, the HLAs were to be replaced with a modified version. As far as I know, replacing the cylinder head wasn't discussed in the tech bulletins covering this problem.

It's not clear if the ticking HLA problem could happen if somehow cylinder deactivation was disabled.