So the new designed phasers are failing as well? I admit I was guessing on the oil pressure being the calibration change (thanks for clearing up what the programming is effecting). My issue is even with the duty cycle being effected why revert back for the updated designed phasers. I find it impossible to believe that only poorly maintained engines were the ones failing with the old design. Just still seems like a bandaid to try and get owners out past the mileage that ford is willing to be involved.
You’re talking about 2 completely separate issues here. And no, the new phasers are not failing.
The reason for the TSB and subsequent recall (21B10) was cam phaser noise on a cold start due to cam phaser locking pin wear. Ford released a redesigned phaser to prevent the issue, but the root cause of failure on the original parts was ultimately determined to be calibration duty cycle. It was not maintenance related.
The new software (21B10) prevents the issue from developing on the original phasers, which is why it was released as a recall. For phasers that already failed, dealers either perform the TSB to replace them (powertrain warranty) or replace them under the extended warranty coverage 21N03.
21N08 was released after it was found that poorly maintained or engines ran low on oil that had excessive cam journal wear were experiencing VCT shudder after 21B10. 21N08 then reverts the calibration back to it’s original state. It has nothing to do with the phaser part number that is installed.
