Engine Coolant Temperature Sensor Guide for the 1995-2001 Plymouth Neon
Here is what you need to know about the Engine Coolant Temperature Sensor for your Plymouth Neon before you buy a replacement.
- Verify your year! 1995-1999 Neons use a different sensor (p/n 4661341) than 2000-2001 models (p/n 56027873).
- Symptoms like bad gas mileage, overheating, or a constant check engine light (P0117/P0118) point to this sensor.
- Replacement is easy for DIYers and located on the driver's side rear of the cylinder head.
- A quality aftermarket brand like NGK or Delphi offers reliable performance for a fraction of the OEM price.
Understanding the Coolant Temperature Sensor in Your Neon
The engine coolant temperature (ECT) sensor in your 1995-2001 Plymouth Neon is a simple but critical component. It is a special type of resistor called a thermistor, which changes its electrical resistance based on temperature. The engine computer (ECU) sends a 5-volt signal to the sensor and reads the voltage that comes back to determine how hot the engine is. When the engine is cold, the sensor has high resistance. As the engine warms up, the resistance drops. This information tells the ECU how to adjust the air-fuel mixture, control the idle speed, and when to activate the cooling fans to prevent overheating.
Common Symptoms of a Failing ECT Sensor
When the ECT sensor starts to fail, it can send wrong information to the ECU, causing a variety of problems. Look out for these common signs:
- Check Engine Light: This is often the first sign. The ECU will store a trouble code when it detects a problem with the sensor's circuit.
- Poor Fuel Economy: If the sensor incorrectly tells the ECU the engine is cold, the computer will enrich the fuel mixture, wasting gas.
- Black Smoke from Exhaust: A very rich fuel mixture can result in black smoke coming from the tailpipe.
- Engine Overheating: If the sensor fails to tell the ECU that the engine is hot, the cooling fans may not turn on when needed.
- Cooling Fans Always On: As a fail-safe, the ECU might run the cooling fans constantly if it gets an illogical signal from the sensor.
- Hard Starting or Rough Idle: An incorrect temperature reading can make it difficult for the engine to start, especially when cold, and can cause a shaky or unstable idle.
A Critical Ordering Mistake for Neon Owners
The 1995-2001 Plymouth Neon uses two different ECT sensors depending on the model year. It is very important to order the correct one for your car.
- 1995-1999 Models: Use part number 4661341.
- 2000-2001 Models: Use part number 56027873.
Always verify the part number and connector shape before purchasing to avoid installation problems.
Choosing the Right Aftermarket Sensor
For a vehicle like the 1995-2001 Neon, a quality aftermarket sensor is a smart and cost-effective choice. The original Mopar parts can be expensive and may not offer a significant advantage in longevity for a car of this age. However, not all aftermarket brands are created equal. Here’s a breakdown of available brands:
- Premium Aftermarket (NGK, Delphi): Brands like NGK (also known as NTK) and Delphi are often original equipment suppliers for many car manufacturers. They are known for reliable and accurate sensors that perform closely to OEM standards. These are a solid choice for peace of mind.
- Standard Aftermarket (Standard Ignition, Four Seasons, Holstein): These brands offer a good balance of quality and price. Standard Ignition (SMP) and Four Seasons are well-known names in the aftermarket and generally produce reliable parts that meet or exceed OEM specifications for fit and function.
- Economy Brands (Walker Products, True Tech): These brands focus on providing the most affordable option. While they can get the job done, their long-term reliability and accuracy may not match that of the premium or standard tiers. They are a viable option for a budget-focused repair.
Cost of Replacing a Plymouth Neon ECT Sensor
The cost to replace the ECT sensor is relatively low. The part itself is inexpensive, and the labor is minimal for a professional mechanic.
| Part Type | Estimated Cost |
|---|---|
| New Aftermarket Sensor | $13 - $55 |
| New OEM (Mopar) Sensor | $40 - $85 |
| Shop Labor | $50 - $100 |
| Total Professional Replacement | $63 - $155 |
DIY Installation Tips
Replacing the ECT sensor on a Neon is a straightforward job for a DIYer with basic tools. The sensor is located on the driver's side of the engine, at the rear of the cylinder head. You will need a deep socket to remove and install it. Let the engine cool completely before you start. Be prepared for a small amount of coolant to spill out when you remove the old sensor; have the new sensor ready to install quickly to minimize loss. Do not overtighten the new sensor, as this can damage the threads. After installation, top off your coolant and check for leaks.
Frequently Asked Questions (FAQ)
Where is the coolant temperature sensor on a 1995-2001 Plymouth Neon?
The sensor is located on the driver's side of the engine, at the back of the cylinder head, often underneath the heater hoses. You may need to remove the air intake tube for better access.
What trouble codes are related to a bad ECT sensor?
The most common codes are P0117 (Engine Coolant Temperature Sensor Circuit Low) and P0118 (Engine Coolant Temperature Sensor Circuit High). A P0117 code often points to a short in the wiring or a bad sensor, while a P0118 code usually means an open circuit, like an unplugged or broken wire.
Were there any recalls for the Neon's ECT sensor?
No, searches of the NHTSA database did not find any recalls or technical service bulletins (TSBs) specifically related to the engine coolant temperature sensor for the 1995-2001 Plymouth Neon.
Can I drive my Neon with a bad coolant temperature sensor?
It is not recommended to drive for an extended period. A bad sensor can cause poor fuel economy, hard starting, and potentially lead to the engine overheating if the cooling fans don't operate correctly. It's best to get the sensor replaced as soon as possible.
Technical Specifications
OEM Part Numbers: 4661341 56027873
This is a two-wire thermistor sensor that measures coolant temperature. There are two distinct versions: one for 1995-1999 models and another for 2000-2001 models, which differ in their connector and threading. Ensure you select the correct part number for your vehicle's year.
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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.
- Plymouth Neon:
- 🛍️ Shop This Part
- Understanding the Coolant Temperature Sensor in Your Neon
- Common Symptoms of a Failing ECT Sensor
- A Critical Ordering Mistake for Neon Owners
- Choosing the Right Aftermarket Sensor
- Cost of Replacing a Plymouth Neon ECT Sensor
- DIY Installation Tips
- Frequently Asked Questions (FAQ)
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