2021 RAM 2500 Problems: 13 Known Issues

On the 2013-2025 RAM 2500 6.7 Cummins, the 2013+ RAM 2500 6.7L Cummins diesel DEF (Diesel Exhaust Fluid) system is plagued with failures of the DEF heater, DEF pump, DEF injector, NOx sensors, and SCR catalyst. The DEF system is required for emissions compliance, and when it fails, the truck enters a "limp mode" that limits speed to 5 mph after a countdown timer expires. DEF heater failures are most common in cold climates where the fluid freezes and cracks the heater element. TSB 18-018-20 addresses DEF heater and quality sensor issues. The NOx sensors (inlet and outlet) fail frequently at $300-500 each.

On the 2007-2024 RAM 2500 6.7L Cummins Turbo Diesel, the intake grid (air) heater warms incoming air for cold starts and carries up to ~200 amps through a small threaded stud/bolt secured by a 10mm nut on the intake plenum. Over years of high-current heat cycling the bolt/nut connection deteriorates, arcs, and can break loose. Because it sits directly above the intake runner, gravity pulls the heavy steel stud straight into cylinder #6, destroying the piston, valves, and cylinder head, often the entire engine. Banks Power has documented 200+ failures, some at as little as 40,000 miles. Stellantis has NOT recalled the grid heater assembly itself (a separate 2021-2022 relay recall Y08/Y76 addressed sticking relays, not the bolt).

On the 2014-2024 RAM 2500 6.4L 392 HEMI V8 gas, gas RAM 2500s with the 6.4L (392) HEMI V8 suffer a documented valvetrain defect in which the roller lifter needle bearings fail, the roller stops rolling and drags across the camshaft lobe, wiping out the lobe. The failure is linked to the truck's Multi-Displacement System (MDS/cylinder deactivation): when cylinders are deactivated, oil delivery to the affected lifters is restricted, starving the roller bearings. Owners report onset as a metallic 'HEMI tick' progressing to misfire, dropped cylinder and catastrophic top-end damage. A class-action lawsuit (Petro, et al. v. FCA US LLC, Case No. 1:22-cv-00621, whose named plaintiffs include a 2020 RAM 2500 owner) alleges FCA knew of the defect since at least 2012 and failed to disclose it. There is no safety recall, so repairs typically fall on the owner once warranty lapses.

On the 2007-2024 RAM 2500 6.7L Cummins Turbo Diesel, the Holset HE351VE variable-geometry turbocharger uses an electronically controlled actuator (the geartrain and control board that moves the vane sliding ring) that is a well-documented failure point, often before 100k miles. Soot and carbon buildup, rust/corrosion binding the vane arm, worn actuator gears, or a corroded circuit board (from coolant/water intrusion) cause the actuator to stop positioning the vanes correctly. The truck then either spools quickly but chokes at mid/high rpm or spools slowly with a big loss of low-end torque, and typically drops into limp mode. Owners on Cummins forums report repeat failures and note the unit must be scan-tool programmed to the specific turbo after replacement.

On the 2003-2025 RAM 2500, the RAM 2500 (and 3500) with solid front axle experiences a violent front-end oscillation known as "death wobble" that occurs at highway speeds (45-65 mph), typically triggered by hitting a bump or pothole. The steering wheel shakes uncontrollably and the entire front end vibrates violently, making the truck nearly undrivable until the driver slows to a stop. The issue is caused by worn or loose front-end components working together in resonance: track bar, ball joints, tie rod ends, unit bearings, steering stabilizer, and steering gear box. NHTSA has received thousands of complaints. TSB 19-001-14 REV.B addresses front axle steering linkage inspection.

On the 2003-2025 RAM 2500, the RAM 2500/3500 steering gear box (power steering box) develops fluid leaks from the input shaft seal and sector shaft seal, and excessive play in the steering. The leak starts as a slow drip and worsens over time, eventually causing low power steering fluid and potential pump damage. Excessive play manifests as a "dead zone" in the steering where the wheel moves 1-2 inches without the wheels turning. The gear box also loosens from the frame due to the high stresses of the solid front axle design. Tightening the adjustment screw on the gear box can temporarily reduce play, but eventual replacement is needed.

On the 2010-2025 RAM 2500, the rear driveshaft U-joints in the RAM 2500 fail prematurely, particularly on trucks used for towing. The factory U-joints are undersized for sustained heavy load use, and the grease fittings (where present) are often overlooked during maintenance. Symptoms start with a clicking or clunking sound during acceleration and deceleration, progressing to vibration at highway speed. Complete U-joint failure can cause the driveshaft to drop, which is a serious safety hazard.

On the 2010-2025 RAM 2500, the BorgWarner BW4470 (part-time 4WD) and BW4494 (full-time 4WD) transfer cases develop fluid leaks at the front and rear output shaft seals and at the case halves. The leaks are often slow and go unnoticed until the fluid level drops enough to cause whine, grinding, or failure to engage 4WD. Trucks used for towing are more susceptible due to higher operating temperatures.

On the 2019-2025 RAM 2500 6.7L Cummins, the 2019+ RAM 2500 with the 6.7L Cummins diesel uses a Bosch CP4.2 high-pressure fuel injection pump that is prone to catastrophic self-destruction. The CP4.2 relies on diesel fuel for internal lubrication, and any contamination, water intrusion, or low fuel levels cause the pump to disintegrate, sending metal shavings throughout the entire fuel system. This contaminates fuel injectors ($500+ each x6), fuel rails, fuel lines, and the fuel tank, requiring a complete fuel system replacement costing $8,000-12,000+. The previous-generation CP3 pump was far more reliable. Multiple class-action lawsuits have been filed against Stellantis/Bosch.

On the 2007-2024 RAM 2500 6.7L Cummins Turbo Diesel, the 68RFE 6-speed automatic behind the Cummins is prone to torque converter shudder and lockup failure. The factory converter's clutch material and heat control are marginal for the Cummins' torque, so the torque converter clutch (TCC) chatters, slips, or refuses to hold lockup, felt as a low-speed vibration like driving over rumble strips. The TCC regulator valve wears its bore in the valve body, making apply pressure erratic. The resulting heat contaminates the fluid and cascades into planetary and clutch-pack damage. Heat is the number-one killer, especially when towing; fluid temps regularly over 200°F accelerate failure.

On the 2007-2024 RAM 2500 6.7L Cummins Turbo Diesel, the EGR cooler routes hot exhaust through a coolant-jacketed heat exchanger before recirculating it into the intake. Heavy soot loading progressively plugs the cooler and EGR valve, first showing as slight off-idle hesitation and rising EGTs, then triggering EGR flow/performance codes and limp mode. Worse, a clogged, thermally stressed cooler can crack internally and leak coolant into the exhaust/intake stream, causing white smoke, coolant loss, and potential hydrolock or catastrophic engine damage. Cummins service intervals call for cleaning the EGR valve/cooler roughly every 67,500 miles (2007.5-2018) or 75,000 miles (2019+), which many owners never perform.

On the 2014-2022 RAM 2500, the center high-mounted third brake light on RAM 2500 trucks is a chronic water-leak point across both the 4th (2010-2018) and 5th (2019+) generations. The thin foam gasket sealing the lamp housing to the cab roof compresses, dries out and degrades, letting rainwater pass through the mounting holes into the cab sheet metal. Because of how the roof slopes, water runs down and shows up as staining on the headliner in the rear corners above the back glass. Beyond cosmetic damage, water frequently drips onto interior electronics — owners report soaked and corroded Body Control Modules (BCM) and other connectors, escalating a cheap seal failure into an expensive electrical fault.

On the 2010-2025 RAM 2500 6.7L Cummins, the cast iron exhaust manifold on the 6.7L Cummins turbo diesel cracks due to thermal cycling stress, particularly near the center cylinders (#3 and #4). Cracks allow exhaust gases to escape, creating a ticking noise on cold start that diminishes as the manifold expands when warm. Exhaust leaks can also send soot into the engine bay and affect turbocharger performance by reducing exhaust backpressure to the turbine.