Pulsar LT to deactivate DFM and prevent lifter fail?

[brewtus]

 

OK, I just kicked over 8k miles on my '21. I was purposely waiting until then to disable DFM to make sure I didn't have the lifter failure, as the original TSB was for 8k to replace both banks if they fail, now its up to 16k miles. Anyhow, I am thinking of the Pulsar LT to prevent the switching on/off all the time and minimize the opportunities for failure. Also, I can hear and slightly feel the DFM kicking in on highway even with stock exhaust. I want 10th gear back on the highway and not have to run L9! With all that said, has anyone had the Pulsar on to disable DFM for extended mileage WITHOUT lifter failures. Looking for some good evidence to support purchasing one other than just getting rid of the nuisance of it.

Also, I did run an '07 up to 130k+ miles with AFM and no failures, and had a '16 with DFM that went to 28k OK, but want to keep this truck well into the 100k+ mileage range

  

[diyer2]

Lifter failure is a roll of the dice no matter what has or hasn't been done IMO. But it won't hurt to disable V4 mode.

The one thing that I believe helps is shorter OCI's. 

[KARNUT]

17 minutes ago, brewtus said:

 

OK, I just kicked over 8k miles on my '21. I was purposely waiting until then to disable DFM to make sure I didn't have the lifter failure, as the original TSB was for 8k to replace both banks if they fail, now its up to 16k miles. Anyhow, I am thinking of the Pulsar LT to prevent the switching on/off all the time and minimize the opportunities for failure. Also, I can hear and slightly feel the DFM kicking in on highway even with stock exhaust. I want 10th gear back on the highway and not have to run L9! With all that said, has anyone had the Pulsar on to disable DFM for extended mileage WITHOUT lifter failures. Looking for some good evidence to support purchasing one other than just getting rid of the nuisance of it.

Also, I did run an '07 up to 130k+ miles with AFM and no failures, and had a '16 with DFM that went to 28k OK, but want to keep this truck well into the 100k+ mileage range

  

There seems to be two narratives in regards to the deactivation saga. Some have bad parts, and the need for more frequent oil changes. Generally the deactivation process doesn’t give much individually for mileage. I would buy extended warranty and decide keeping at that point. As far as deactivation I’d have to be convinced of warranty implications before proceeding.  

[dieselfan1]

On 9/19/2022 at 7:39 AM, diyer2 said:

 

The one thing that I believe helps is shorter OCI's. 

Exactly. 

I change both my 22s every 3000 miles with Royal Purple 0 20w.

The rest of the motor likes clean oil too.

[brewtus]

1 minute ago, dieselfan1 said:

Exactly. 

I change both my 22s every 3000 miles with Royal Purple 0 20w.

The rest of the motor likes clean oil too.

Totally agree.  Do that to all my vehicles, can't hurt but hope it IS the solution.  

[Robby James]

I did it and am pleased, over 20k miles now on the Pulsar

 

Edited October 9, 2022 by Robby James
added info

[SporkLover]

It will certainly reduce the risk as the DFM isn't being activated but the risk is the mechanical parts are still there.  Previous generations of AFM had shown disabiling AFM doesn't completely remove the risk.  It can still fail. 

 

Only thing that can fix it is removing the DFM lifters. 

[jaxcam02]

On 11/10/2022 at 3:32 PM, SporkLover said:

It will certainly reduce the risk as the DFM isn't being activated but the risk is the mechanical parts are still there.  Previous generations of AFM had shown disabiling AFM doesn't completely remove the risk.  It can still fail. 

 

Only thing that can fix it is removing the DFM lifters. 

This, as soon as my warranty is over (if I still have the truck) I will be pulling the heads and putting non DFM lifters in. This is truly the only was to prevent it. Luckily I have one of the lucky trucks that don't have DFM activated from GM.

[ShotgunZ71]

The refreshed models, and most 2019+ with the 10-speed transmission are not yet compatible with the Pulsar, Range, etc to disable DFM or autostop. Entirely new electrical infrastructure on the refreshed models, making it more difficult to "hack" and make changes.

[dgstarr63]

My 21 5.3 DFM lifters failed at about 10000 miles with the DFM disabled with a Range. This was probably caused by defective lifters. I am still using the Range because I belive the DFM lifters are a failure prone design. Mine was built during the defective lifter time frame, but I belive all of them are more likely to fail if they are constantly locking and unlocking.