Which parts fail
Components named in complaints (engine, cooling system, oil leaks, timing chain, exhaust).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2012 Dodge Ram 3500 owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owned a 2012 Dodge Ram 3500. The contact stated that while the vehicle was parked, a fire started under the hood. The fire was extinguished by the fire department. The hood was completely consumed by the fire. The fire department declared the vehicle a total loss. The contact stated that inspection by the fire department declared that the fire was an electrical fire that started on the driver's side under the hood. The contact associated the failure with NHTSA Campaign Number: 14V635000 (Engine and Engine Cooling, Fuel System, Diesel); however, the VIN was not included in the recall. The manufacturer was contacted by phone and was made aware of the failure. The failure mileage was approximately 259,500.
The contact owns a 2012 Ram 3500. The contact stated that while that while the vehicle was in for service, the independent mechanic discovered fuel leaking from the fuel filter heater assembly. The contact was advised that the fuel filter heater assembly needed to be replaced. The vehicle was not yet repaired. The manufacturer and local dealer were notified of the failure, but no assistance was offered. The contact was informed that the vehicle was previously repaired under NHTSA Campaign Number: 14V635000 (ENGINE AND ENGINE COOLING, FUEL SYSTEM, DIESEL). The contact stated that the vehicle had experienced the failure listed in the recall. The failure mileage was 202,000.
Driving my 2012 dodge ram 3500, just as I was crossing one of the busiest intersections in my town my truck lost all power and dropped from 35mph to 5 mph. Barley made it acrossed and pulled over. As soon as I pulled over the engine light comes on, checked code, and U010C lost coms with turbo actuator comes up. Turned truck off and rest code and everything back to normal. About a week later it happened again, luckily not as busy of a spot. Called dealer and soonest appointment was in April. Meanwhile I look up code and see hundreds of post for same issue, bad actuator replace. 28 years as a diesel mechanic for the military, so I found the part online and ordered. Replaced the actuator, drove about 50 miles, light comes back on. Finally get my appointment with dealer and they say my turbo is bad, they want $8k to fix. …
This truck has had to have several high temp burnoffs because of failures in the EGR and Carbon build up. The recent recall for Rams does not cover the 2012, and began at 2013, however, we are experiencing the same exact issues with the same type of system. In addition, we have had repeated airbag issues due to the positioning of the cockspring and wiring getting choked out.
The wireless ignition module loses connection internally and the truck will lose power while driving. It usually happens when hitting a small bump and the key in the ignition moves. Truck loses electrical power which shuts the engine off which means loss of power steering and brakes.
At approximately 11:30 pm, I heard a vehicle horn honking outside in the driveway. Got out of bed to investigate. Observed my 2102 Ram 3500 diesel truck with lights on and flashing and horn was honking. Keys for truck were in the house. Went outside with keys and tried key-less entry fob to open the cab door with no success. Smelled smoke. Opened drivers side door with regular key to see lights on dashboard all lit up. Opened the hood to see lots of smoke and observed glowing wiring harness next to driver's side battery. Harness was glowing orange all the way from the firewall to the fuse box (power distribution module) next to battery. Went into garage to get wrenches and fire extinguisher. Disconnected driver side battery but the electrical harness was still glowing orange and smoking. …
The 2012 Dodge Ram 3500 4x4 6.7 diesel will intermittently stop running. The gauges will all go dead, the engine will stop running and will not start up again until the vehicle is completely stopped, put in park and key turned off and then back on again. It does not matter if the vehicle is at high or low speeds, with or without a load, pulling a trailer or running empty. Once it has started back up, it May run for a couple of weeks or a couple of hours before it does it again. It does not seem to be affected by temperature or weather because it has happened in hot and cool weather and wet and dry conditions. Yesterday it happened when I was merging onto the freeway at 70 MPH. Last week it happened when I was pulling out of my driveway at less than 5 MPH. …
Tl* the contact owns a 2012 Ram 3500. The contact stated that while driving at various speeds, there was an abnormal sound coming from the vehicle. The vehicle was taken to griffin Chrysler Dodge Jeep Ram (1121 s main st, jefferson, wi 53549) where the vehicle was diagnosed and it was determined that the water pump bearing was defective and needed to be replaced. The vehicle was repaired. The contact referenced NHTSA campaign number: 17V562000 (engine and engine cooling) as a possible solution to the failure however, the VIN was not included. The manufacturer was informed of the failure. The failure mileage was approximately 37,000. Consumer stated engine and water pump both subject to a recall but vehicle was not included in the recall.
Tl* the contact owns a 2012 Dodge Ram 3500. The contact stated that the vehicle was repaired under NHTSA campaign number: 11V350000 (steering) and NHTSA campaign number: 13V529000 (steering). The contact mentioned that the recall remedy details for NHTSA campaign number: 13V529000 (steering) and associated documents information did not match. In addition, the engine warning indicator illuminated while driving various speeds. The vehicle was taken to the dealer, who stated that the emissions o2 sensors failed. The 02 sensor was replaced numerous times on separate occasions. The manufacturer was notified of the failure. The approximate failure mileage was 4,000.
While driving the vehicle completely looses all power,press on the accelator and nothing and after about 6 seconds it's back to normal,,this has happened on the freeway and on city streets...I called Chrysler about the problem and was told there was no recall and for me to take it in to the dealer and tell them about it,I took it in today and they checked for trouble codes and said there were none and no recalls were on the truck for that problem and there was nothing they could do about it...the truck is a diesel and only has 32000 miles...and has no warranty.
Engine complaints in other Ram 3500 years
Frequently asked questions
How common are engine problems on the 2012 Dodge Ram 3500?
NHTSA has 44 complaints about the engine & cooling of the 2012 Dodge Ram 3500, 12% of the model year's 366 complaints. The component named most often is engine › diesel (5 mentions).
Is there a recall for 2012 Dodge Ram 3500 engine problems?
No. NHTSA lists no engine & cooling recall for the 2012 Dodge Ram 3500, though it has 8 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2012 Dodge Ram 3500 engine problems start?
Half of the complaints with a recorded mileage happened before about 87,000 miles, and 13% before 25,000 miles.
Is it dangerous?
Owners linked 0 crashes, 2 fires and 0 injuries to engine & cooling problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.