2021 Ford F-250 SD engine problems

11 owner complaints filed with NHTSA name the engine on the 2021 Ford F-250 SD — 7% of all complaints for this model year.

Engine complaints

share of all complaints

—

median reported incident mileage

0 / 0

crash / fire reports

What owners report

“I took a functional vehicle to Swant Graber Ford in Barron, WI in on [XXX] for Recall 24S78 and since then I have had numerous vehicle issues involving the PCM that they flashed. I have up to 16 different codes when the check engine light comes on including numerous communication U-codes indicating…”
filed Jul 1, 2026
“2021 f250 with the 7.3v8. 120000 miles and lifter has failed. We believe that we caught it early enough to where we have no more issues other than this. After reading up I have noticed where there has been several other customers with same issue on this engine. I run several f350 pickups with our…”
filed Mar 5, 2026

Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.

Customer Satisfaction Program 25M01 Certain 2021 Model Year F-150 3.0L Diesel Engine and 2020-2022 Model Year Super Duty with 6.7L Diesel Engine Nitrogen Oxide (NOx) Sensor Replacement, If Required After Dealer…
25M01 · Other · issued Jul 28, 2026
This article supersedes TSB 25-2572 to update the Parts List to correct the part number LC3Z-6006-L to LC3Z-6781-A, remove the flex plate bolts AL3Z-6379-BA from the parts list as these bolts are in kit LC3Z-6781-A…
TSB 26-2256 · Service Bulletin/Repair Instructions · issued Jun 19, 2026
Some 2021-2026 F-150 vehicles equipped with a 5.0L/5.2L engine, 2021-2025 F-Super Duty/F-53 Motorhome/F59 Commercial Stripped Chassis vehicles equipped with a 6.8L/7.3L engine and 2021-2025 E-Series/F-650/F-750 vehicles…
SSM 54678 · Service Bulletin/Repair Instructions · issued Mar 20, 2026