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          AISIN THT-004 - Engine Coolant Thermostat

          MPN: THT-004
          0.0
          Vehicle Specific
          Check if this part fits your vehicle.
          • $28.28
          In stock

          Product Overview

          The AISIN THT-004 Engine Coolant Thermostat is designed to regulate your vehicle's engine temperature, ensuring optimal performance and efficiency. With OE-level quality and reliable fitment, this thermostat is perfect for discerning drivers who demand the best for their Lexus vehicles. AISIN is a trusted brand in the automotive industry, known for its high-quality components. Choose AISIN THT-004 for dependable performance and peace of mind every time you service your vehicle.

          Cross Reference Numbers

          This AISIN THT-004 is equivalent to or replaces the following part numbers:

          16031-31020, 1603131020, THT004, 34711, 143-0879, 1430879, WH-TB-82, WHTB82, 660-180, 660180

          Vehicle Compatibility

          • Lexus IS250 2.5 V6 (2006-2015)
          • Lexus IS350 3.5 V6 (2006-2017)
          • Lexus GS350 3.5 V6 (2007-2015)
          • Lexus GS450h 3.5 V6 (2007-2018)
          • Lexus RC350 3.5 V6 (2015-2017)
          • Lexus RC300 3.5 V6 (2016-2017)
          • Lexus IS300 3.5 V6 (2016-2018)
          • Lexus GS300 3.0 V6 (2006)

          This also fits other applications. Please use the vehicle selector tool to verify fitment.

          Why Choose Newparts.com?

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          Frequently Asked Questions

          What symptoms indicate that I need to replace the AISIN THT-004 thermostat?

          If your vehicle is experiencing overheating, fluctuating temperature readings, or poor engine performance, it may be time to replace the AISIN THT-004 thermostat.

          How does the AISIN THT-004 thermostat work?

          The AISIN THT-004 thermostat regulates the flow of coolant to maintain the engine at an optimal operating temperature, which is essential for both performance and fuel efficiency.

          What DTCs are associated with thermostat issues?

          Common Diagnostic Trouble Codes (DTCs) related to thermostat problems include P0128, P0116, and P0117, which indicate issues with engine temperature regulation.

          How do I know if the AISIN THT-004 is the right fit for my vehicle?

          To ensure compatibility, check your vehicle's specifications and compare them with the AISIN THT-004. You can also use our vehicle selector tool for verification.

          Why should I order the AISIN THT-004 thermostat?

          Order AISIN THT-004 today for a factory-correct replacement that restores safety and performance.

            • Newparts SKU
              204330
            • Weight
              0.4 lbs
            • Barcode
              4580281458692
            • Dimensions (L x W x H)
              4.2 x 4.2 x 3.75 in
            • Manufacturer Part #
              THT-004
          • Brand
            AISIN
          • Manufacturer
            AISIN
          • MPN
            THT-004
          • Features
            Bolt Hole Quantity : 3
            Design : Integrated Housing
            Material : Brass
            Material : Stainless Steel
            Start to Open Temperature : 82.0
          • OE Part Numbers
            16031-31020, 1603131020
          • Cross Reference Numbers
            THT004, 34711, 143-0879, 1430879, WH-TB-82, WHTB82, THT-004, 660-180, 660180
          • Part Type
            Engine Coolant Thermostat
          • Fitment
            • Fitment Type
              Vehicle Specific
          YearMakeModelSubmodelNotes
          2006LexusGS300Base (3.0 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2006LexusIS250Base (2.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2006LexusIS350Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2007LexusGS350Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2007LexusIS250Base (2.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2007LexusIS350Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2007LexusGS450hBase (3.5 V6 FHEV)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2008LexusGS350Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2008LexusIS250Base (2.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2008LexusIS350Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2008LexusGS450hBase (3.5 V6 FHEV)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2009LexusIS250Base (2.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2009LexusIS350Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2009LexusGS350Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2009LexusGS450hBase (3.5 V6 FHEV)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2010LexusIS250Base (2.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2010LexusIS250C (2.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2010LexusIS350Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2010LexusIS350C (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2010LexusGS350Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2010LexusGS450hBase (3.5 V6 FHEV)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2011LexusGS350Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2011LexusIS250Base (2.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2011LexusIS250C (2.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2011LexusIS350Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2011LexusIS350C (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2011LexusGS450hBase (3.5 V6 FHEV)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2012LexusIS250Base (2.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2012LexusIS250C (2.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2012LexusIS350Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2012LexusIS350C (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2013LexusGS350Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2013LexusGS350F Sport (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2013LexusIS250Base (2.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2013LexusIS250C (2.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2013LexusIS350Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2013LexusIS350C (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2013LexusGS450hBase (3.5 V6 FHEV)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2014LexusIS250Base (2.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2014LexusIS250C (2.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2014LexusIS250C F Sport (2.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2014LexusIS250F Sport (2.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2014LexusIS350Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2014LexusIS350C (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2014LexusIS350C F Sport (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2014LexusIS350F Sport (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2014LexusGS350Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2014LexusGS350F Sport (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2014LexusGS450hBase (3.5 V6 FHEV)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2015LexusIS250Base (2.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2015LexusIS250C (2.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2015LexusIS250C F Sport (2.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2015LexusIS250F Sport (2.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2015LexusIS350Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2015LexusIS350C (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2015LexusIS350C F Sport (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2015LexusIS350F Sport (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2015LexusGS350Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2015LexusGS350F Sport (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2015LexusRC350Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2015LexusRC350F Sport (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2015LexusGS450hBase (3.5 V6 FHEV)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2015LexusGS450hF Sport (3.5 V6 FHEV)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2016LexusRC350Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2016LexusRC350F Sport (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, 82°C (180°F) OE Temp Thermostat
          2016LexusIS300Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C
          2016LexusIS300F Sport (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C
          2016LexusIS350Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C
          2016LexusIS350F Sport (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C
          2016LexusRC300Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C
          2016LexusRC300F Sport (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C
          2016LexusGS450hBase (3.5 V6 FHEV)Notes: Integral Thermostat & Housing, 82°C
          2016LexusGS450hF Sport (3.5 V6 FHEV)Notes: Integral Thermostat & Housing, 82°C
          2017LexusRC300Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C
          2017LexusRC300F Sport (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C
          2017LexusRC350Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C
          2017LexusRC350F Sport (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C
          2017LexusIS300Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C
          2017LexusIS300F Sport (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C
          2017LexusIS350Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C
          2017LexusIS350F Sport (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C
          2017LexusGS450hBase (3.5 V6 FHEV)Notes: Integral Thermostat & Housing, 82°C
          2017LexusGS450hF Sport (3.5 V6 FHEV)Notes: Integral Thermostat & Housing, 82°C
          2018LexusIS300Base (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, To 9/2017
          2018LexusIS300F Sport (3.5 V6 GAS)Notes: Integral Thermostat & Housing, 82°C, To 9/2017
          2018LexusGS450hBase (3.5 V6 FHEV)Notes: Integral Thermostat & Housing, 82°C
          2018LexusGS450hF Sport (3.5 V6 FHEV)Notes: Integral Thermostat & Housing, 82°C
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          Warranty Overview

          At Newparts, we stand behind the quality of the products we sell. Every part we offer is backed by a warranty designed to give you peace of mind and protect your investment.

          Standard Warranty – Most Parts

          • Coverage: 2 years or 24,000 miles (whichever comes first) from purchase date.

          • Protection: Defects in materials or workmanship under normal personal use.

          • Eligibility: Applies only to the original purchaser and the vehicle where the part was first installed.

          • Exclusions:

            • Wear-and-tear items (brake pads, filters, bulbs, wipers, etc.)

            • Commercial, fleet, rideshare, off-road, or racing use

            • Improper installation, misuse, accidents, or modifications

          • Not Covered: Labor, shipping, towing, or incidental costs.

          Bison Performance Warranty – Our House Brand

          • Coverage: Limited Lifetime Warranty for as long as you own your vehicle.

          • Applies To: All products sold under the Bison Performance label.

          • Premium Protection: Goes beyond our standard warranty — if it’s a Bison product, the 2-year/24k mile limit is replaced with lifetime coverage.

          • Exclusions: Same as the standard warranty (normal wear, commercial use, improper installation, etc.).

          • What’s Included: Replacement of the defective product (labor and shipping excluded).

          Warranty Claim Requirements

          To keep claims fast and fair, we require:

          • Proof of purchase (invoice or order confirmation).

          • Photos or videos showing the defective part, order number, date, VIN, and odometer reading.

          • Diagnostic reports or part returns for non-visible issues may be requested.

          • Claims must be truthful, properly documented, and reflect normal consumer use.

          Buy With Confidence: We back our products because we believe in their quality, with a transparent, customer-first warranty process you can trust. And with Bison Performance products, you’ll enjoy Limited Lifetime protection—an assurance few brands can match.

          For full details and exclusions, please see our complete Warranty Terms & Conditions.


          This summary is for convenience only. For full warranty coverage details, exclusions, and requirements, see our official Warranty Terms & Conditions. In case of conflict, the full policy governs.

          Return Policy Overview

          Most parts can be returned within 30 days of delivery if unused, uninstalled, and in original packaging.
          To start a return, use our Return Portal or contact support.

          • Restocking fee: Up to 20% may apply for certain orders (buyer’s remorse, order errors, or special-order items)

          • Refunds: Issued to your original payment method within 3–5 business days after inspection

          • Exchanges: Not automatic — please return and reorder

          • Replacements: May be approved for incorrect or defective items reported within 7 days

          Not returnable:

          • Used or installed parts

          • Electrical components

          • Opened filter kits, gaskets, or contaminated items

          • Final sale or custom orders

          Important Notes:

          • Return shipping is your responsibility unless we made a verified error

          • Fitment is the customer’s responsibility (we can assist, but do not guarantee)

          • Country of origin may vary and is not grounds for return

          For complete details, please see our full Return Policy.



          This Returns summary is provided for convenience only. All returns, refunds, and exchanges are subject to the complete Returns Policy. In the event of any conflict, the full policy governs.

          Fast, Reliable Shipping — Straight to Your Door

          We ship most orders the same day when placed before 2 PM CST (Monday–Friday). Our main warehouse is just east of Nashville, TN, and we also ship from multiple locations nationwide to get your order to you as quickly as possible.

          • We use trusted carriers like UPS, FedEx, and USPS.

          • Tracking info is emailed to you as soon as your order ships.

          • Delivery estimates at checkout are based on carrier data, but not guaranteed.

          Need help with a shipment?

          If your order is missing, damaged, or incorrect, just let us know within 5 days of delivery. We’ll walk you through the quick claim process — including a few photos to help us make things right.

          For full details, please see our complete Shipping Policy.


          This Shipping summary is provided for convenience only. Delivery times, carrier terms, fees, restrictions,  risk of loss, and other details are governed by our complete Shipping Policy. In the event of any conflict, the full policy governs.

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