AISIN THZ-004 - Engine Coolant Thermostat

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.