Ram 1500 Ignition Knock Sensor Guide for 2019-2023 Models
Understand why a small sensor can cause big problems for your Hemi engine's health and performance.
- A bad knock sensor will cause poor performance and fuel economy because the engine's computer will enter a 'safe mode'.
- On the 2019-2023 Ram 1500 5.7L Hemi, the sensors are on the sides of the engine block, not under the intake manifold.
- Common trouble codes are P0325 (Bank 1) and P0330 (Bank 2).
- Ignoring a bad knock sensor can lead to long-term engine damage if a real knock condition occurs.
Is a Bad Knock Sensor a Big Deal?
Yes, it can be. A failing knock sensor can't properly detect detonation. The truck's computer, not getting a clear signal, will often default to a 'safe mode'. This mode retards ignition timing to prevent potential engine damage. The result is noticeably worse performance, poor acceleration, and lower gas mileage. Ignoring it can lead to more serious internal engine problems over time.
Don't Ignore the Check Engine Light
A check engine light for a knock sensor code is your truck’s way of asking for help. Driving with a known bad sensor can mask other issues and potentially lead to expensive engine repairs down the road. Common codes include P0325 and P0330.
Symptoms of a Failing Knock Sensor on a Ram 1500
A bad knock sensor will almost always trigger the Check Engine Light. Beyond that, you might notice:
- Reduced Power and Sluggish Acceleration: The truck may feel hesitant or slow, especially when you hit the gas pedal.
- Worse Fuel Economy: When the computer retards timing to protect the engine, it uses more fuel.
- Engine Pinging or Knocking Noise: You might hear a metallic pinging or rattling sound, especially when the engine is under load, like when towing or accelerating hard.
- Rough Idle: In some cases, a faulty sensor can contribute to a rough or erratic idle.
Choosing the Right Aftermarket Knock Sensor
When buying a replacement, you have a few options. Not all aftermarket parts are created equal, especially sensitive electronics like knock sensors.
Tier 1: OEM-Quality Brands
- Delphi: Delphi is often an Original Equipment (OE) supplier for many manufacturers. Choosing Delphi is often like getting the same quality as the Mopar part without the dealership price tag. It's a highly trusted brand for sensors.
Tier 2: Reputable Aftermarket Brands
- Dorman: Dorman is a huge name in the aftermarket and offers a wide variety of parts. For a part like a knock sensor, their quality is generally considered decent for daily driving, but some professional mechanics and users have reported mixed results on sensors.
- Walker Products: Walker is another established aftermarket brand. They provide a cost-effective alternative to OEM parts and are a viable option for budget-conscious repairs.
Tier 3: Budget-Friendly Options
- Global Parts: These are typically the most affordable options. While they meet basic fit and function requirements, their long-term durability and sensitivity may not match that of higher-tier brands. They can be a choice for a quick fix on a tight budget.
A Note on Hemi Knock Sensor Location
On the 5.7L Hemi engine used in the 2019-2023 Ram 1500, the two knock sensors are located on the sides of the engine block, below the exhaust manifolds. This is a change from some older GM engines where they were under the intake manifold. While this makes them easier to access without removing the intake, they can still be tricky to reach.
Cost of Replacing a Ram 1500 Knock Sensor
The cost can vary significantly based on who does the work. The parts themselves are affordable, but shop labor can add up.
| Part or Service | Estimated Cost |
|---|---|
| New OEM (Mopar) Knock Sensor | $70 - $110 per sensor |
| New Aftermarket Knock Sensor | $27 - $67 per sensor |
| Shop Labor | $100 - $200 |
| Total Professional Replacement (Aftermarket Part) | $265 - $301 |
Frequently Asked Questions
Where are the knock sensors on a 2019-2023 Ram 1500 5.7L Hemi?
The Ram 1500 with the 5.7L Hemi has two knock sensors. They are located on the sides of the engine block, one on the driver's side and one on the passenger's side, below the exhaust manifolds. You typically access them from the wheel well or from underneath the truck.
Should I replace both knock sensors at the same time?
It's a good practice, but not always necessary. If one has failed due to age and heat cycles, the other may not be far behind. Since accessing them can be time-consuming, replacing both at once can save you from having to do the job again in the near future. If only one is throwing a code, you can choose to replace just that one.
What happens if I don't replace a bad knock sensor?
Your truck will continue to run in a reduced-power state, with poor fuel economy and performance. More importantly, the engine's main protection against harmful detonation is offline. If a real knock condition develops from bad fuel or another issue, the computer won't be able to correct for it, which can lead to piston, ring, or bearing damage.
Is there a recall for the knock sensor on the 2019-2023 Ram 1500?
As of late 2024, there are no specific recalls issued by the NHTSA for the ignition knock sensor on the 2019-2023 Ram 1500. There is a TSB (18-002-25) related to PCM updates for misfires and other issues, but it does not directly address knock sensor failure.
Helpful Videos
Technical Specifications
OEM Part Numbers: 68570138AA 68223050AA
The 5.7L Hemi V8 engine uses two knock sensors, one for each cylinder bank. They are piezoelectric sensors that generate an AC voltage signal in response to engine vibrations. Proper installation torque is critical for accurate readings; the typical torque spec is around 15 ft-lbs.
We Have This Part in Stock
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.
- Ram 1500: