Lexus IS350 Engine Coolant Temperature Sensor Guide for 2006-2018 Models
Diagnose a faulty coolant temperature sensor in your IS350 and learn how to choose a reliable aftermarket replacement.
- A failing ECT sensor commonly causes a check engine light (P0117/P0118), poor fuel economy, and an inaccurate temperature gauge.
- For reliability, choose an OEM-supplier brand like Denso. Reputable brands like Beck Arnley and Delphi are also good choices.
- The sensor is located in a tight spot under the throttle body, making replacement a patient, 1-2 hour job for a DIYer.
- Driving with a bad sensor is risky due to the potential for engine overheating if the cooling fans don't activate.
Is a Small Sensor Causing Big Problems in Your IS350?
A faulty Engine Coolant Temperature (ECT) sensor can cause a surprising number of issues in the 2006-2018 Lexus IS350. Because the engine's computer relies on this sensor for so much information, a bad signal can lead to poor performance, bad fuel mileage, and even overheating. Understanding the symptoms and knowing how to choose a quality replacement part is key to keeping your Lexus running properly.
Symptoms of a Failing ECT Sensor
- Check Engine Light: The most common sign is a check engine light with codes like P0115, P0117, or P0118. 🎬 Watch: A detailed explanation of P0117 and P0118 diagnostic codes.
- Poor Fuel Economy: The engine may run rich, as if it's always cold, wasting fuel.
- Black Smoke from Exhaust: A rich fuel mixture can result in black smoke from the tailpipe.
- Inaccurate Temperature Gauge: The gauge on your dashboard might stay on cold, jump around wildly, or read hot when the engine isn't.
- Engine Overheating: If the sensor fails to tell the fans to turn on, the engine can overheat, which is a serious risk.
- Rough Idle or Hard Starts: Incorrect fuel and timing adjustments can make the engine run poorly.
Choosing the Right Aftermarket Sensor for Your Lexus
When it comes to electronic sensors for a Lexus, quality matters. A cheap, inaccurate sensor can send the wrong data to your engine's computer, causing performance issues that are hard to diagnose. It's best to avoid the absolute cheapest options. Here’s a breakdown of available aftermarket brands.
Tier 1: OEM Supplier
Denso: Denso is the original equipment manufacturer for many Toyota and Lexus parts, including sensors. Choosing a Denso sensor is the closest you can get to buying the part from a Lexus dealer, but at a better price. It is the most recommended option in owner forums for guaranteed fit and performance.
Tier 2: Reputable Aftermarket Brands
These brands are known for producing quality components that meet or exceed OEM specifications. They are a solid choice if a Denso part is not available.
- Beck Arnley: This brand specializes in parts for foreign nameplates and often sources its components from OEM suppliers. It's a trusted choice for fit and function.
- Delphi: A major global parts manufacturer with a reputation for reliable electronics.
- NGK / NTK: While famous for spark plugs, NTK (the sensor division of NGK) is a top-tier manufacturer of engine management sensors.
- Standard Ignition (SMP): A long-standing company that produces a wide range of reliable aftermarket parts.
Tier 3: Budget Brands
Brands like URO Parts, Facet, and other lower-priced options are available. However, for critical electronic sensors, caution is advised. Some owners have reported fitment issues and premature failure with budget brands like URO Parts on other vehicles. While the low price is tempting, you may risk creating new performance problems or having to do the job twice.
Cost to Replace the IS350 Coolant Temperature Sensor
| Part Type | Estimated Cost |
|---|---|
| New OEM (Dealer) | $70 - $225 |
| New Aftermarket | $14 - $85 |
| Shop Labor | $100 - $225 |
Pro Tip: Don't Forget the Gasket
The ECT sensor seals to the engine with a small gasket or O-ring to prevent coolant leaks. Always use a new gasket when installing the new sensor. Many quality aftermarket sensors will include one in the box.
Installation Snapshot
Replacing the ECT sensor on the IS350's 3.5L V6 (2GR-FSE) engine is feasible for a DIYer, but access is tight. The sensor is located under the throttle body, near the firewall. To reach it, you will likely need to remove the plastic engine covers, the air intake tube, and possibly the battery for better access. A 19mm deep socket is required for the sensor itself. 🎬 See this walkthrough for replacing the hidden sensor at home. Expect to lose a small amount of coolant during the swap.
Frequently Asked Questions (FAQ)
Can I drive my IS350 with a bad coolant temperature sensor?
You can, but it's not recommended for long. The engine will run inefficiently, burn extra fuel, and may be hard to start. The biggest risk is engine overheating if the sensor fails to activate the cooling fans, which can lead to severe engine damage. It should be repaired as soon as possible.
Is an aftermarket sensor good enough for my Lexus?
Yes, as long as you choose a high-quality brand. An OEM-supplier brand like Denso is ideal. Reputable brands like Beck Arnley, Delphi, or NTK are also reliable choices. Avoid the cheapest unbranded options, as they can cause more problems than they solve.
Where is the engine coolant temperature sensor located on the 2006-2018 IS350?
It is located on the engine block, underneath the throttle body assembly, near the firewall at the back of the engine.
How many coolant temperature sensors does the IS350 have?
The Lexus IS350 uses one primary engine coolant temperature sensor that sends its reading to the engine computer (ECM). This single reading is used for engine management and to drive the temperature gauge on the dashboard.
🎬 Watch: Step-by-step removal and install to fix overheating issues.Helpful Videos
Technical Specifications
OEM Part Numbers: 89422-33030 89422-35010 89422-20010
The sensor is a 2-pin thermistor that screws into a coolant passage on the engine. It typically requires a 19mm deep socket for removal and installation. A new gasket is required.
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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.
- Lexus IS350:
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- Is a Small Sensor Causing Big Problems in Your IS350?
- Symptoms of a Failing ECT Sensor
- Choosing the Right Aftermarket Sensor for Your Lexus
- Tier 1: OEM Supplier
- Tier 2: Reputable Aftermarket Brands
- Tier 3: Budget Brands
- Cost to Replace the IS350 Coolant Temperature Sensor
- Pro Tip: Don't Forget the Gasket
- Installation Snapshot
- Frequently Asked Questions (FAQ)
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