Ram 4500 Ignition Knock Sensor Guide for 2014-2022 Models
Protect your Hemi engine from damage by understanding, diagnosing, and replacing a faulty knock sensor.
- A bad knock sensor will trigger a Check Engine Light (P0325/P0330) and cause poor performance and fuel economy.
- Your Ram 4500 has two sensors, located on the sides of the Hemi engine block, accessible from underneath.
- Top aftermarket brands like NGK (NTK), Delphi, and Standard Ignition offer reliable, cost-effective alternatives to OEM parts.
- Replacing a knock sensor is a manageable DIY task, but correct torque on the mounting bolt is critical for proper function.
Is Your Ram 4500 Knock Sensor Failing?
A bad knock sensor can cause noticeable problems. The engine's computer relies on this sensor to run the engine aggressively for maximum power. When the sensor's signal is gone, the computer plays it safe by reducing performance to prevent damage. This can feel like a loss of power and make your truck feel sluggish.
Symptoms of a Bad Knock Sensor
- Check Engine Light: This is the most common sign. You will likely see trouble code P0325 or P0330 when you scan for codes.
- Engine Pinging Noise: You might hear a metallic pinging or knocking sound, especially when the engine is working hard, like when towing or going up a hill.
- Reduced Engine Power: Your truck may feel less responsive and slower to accelerate.
- Worse Fuel Economy: When the engine runs in its 'safe' mode, it's less efficient, causing you to use more fuel.
No Specific Recalls or Bulletins
Searches for official recalls and Technical Service Bulletins (TSBs) from Ram or the NHTSA did not find any specific issues for the knock sensors on the 2014-2022 Ram 4500. Problems are typically due to normal sensor failure from age and heat cycles.
Choosing the Right Aftermarket Knock Sensor
For a critical part like a knock sensor, quality matters. While OEM Mopar parts are a safe choice, several aftermarket brands offer excellent quality, sometimes from the same factory that makes the original part. Aftermarket sensors are a cost-effective option that can restore your truck's performance.
Aftermarket Brand Tiers
Not all brands are created equal. Here is a general breakdown of the brands available:
- Tier 1 (OE Quality or Equivalent): NGK (NTK) and Delphi are highly respected brands that are often original equipment manufacturers for many car companies. Forum users and mechanics frequently recommend NTK as being on par with OEM quality. Delphi is also a trusted OE supplier with a strong reputation for sensors.
- Tier 2 (Quality Aftermarket): Standard Ignition (Standard Motor Products) and Walker Products are well-known aftermarket manufacturers. Standard Motor Products, in particular, has a reputation for producing reliable parts that meet or exceed OEM specifications and are rigorously tested.
- Tier 3 (Economy): Brands like Beck Arnley, Global Parts, and Motorad often provide the most budget-friendly options. While they can work, some forum discussions on other vehicles mention a higher risk of premature failure with economy sensors. For a part that can be tricky to access, choosing a Tier 1 or Tier 2 brand is often worth the small extra cost to avoid doing the job twice.
Pro Tip: Replace in Pairs?
Your Ram 4500 has two knock sensors. If one has failed due to age and heat, the other one has been exposed to the same conditions and may fail soon. While not strictly necessary, if you are already paying for labor or spending the time to get under the truck, it is wise to consider replacing both sensors at the same time.
Cost of Replacing a Ram 4500 Knock Sensor
The total cost will depend on the price of the part and whether you do the work yourself or hire a professional.
| Part/Service | Estimated Cost |
|---|---|
| New Aftermarket Sensor | $21 - $43 |
| New OEM (Mopar) Sensor | $70 - $150 |
| Shop Labor | $100 - $225 |
| Total (DIY) | $21 - $43 |
| Total (Shop) | $121 - $375 |
Frequently Asked Questions
Where are the knock sensors located on a 2014-2022 Ram 4500?
The two knock sensors on the 6.4L Hemi engine are located on the sides of the engine block, below the exhaust manifolds. One is on the driver's side (Bank 1) and the other is on the passenger's side (Bank 2). Access is from underneath the truck.
Can I replace a knock sensor myself?
Yes, this is a DIY-feasible job for someone with some mechanical experience. It does not require major engine disassembly. You will need basic tools, a way to safely lift the truck, and a torque wrench, as the sensor's mounting bolt must be tightened to a specific torque specification to work correctly.
What is the most common trouble code for a bad knock sensor?
The most common code is P0325, which indicates a circuit malfunction for the Bank 1 (driver's side) sensor. You may also see P0330, which points to the Bank 2 (passenger's side) sensor.
What happens if I don't replace a bad knock sensor?
Your truck's computer will default to a safe mode with reduced ignition timing. This leads to poor performance and bad fuel economy. More importantly, if a real engine knock condition occurs, the computer won't be able to detect it, which could lead to serious and expensive internal engine damage over time.
Technical Specifications
OEM Part Numbers: 68570138AA
The Ram 4500 with a 6.4L Hemi engine uses two knock sensors. They are piezoelectric sensors that generate an AC voltage signal in response to engine block vibrations.
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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
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