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SKU:
NLT1K01474
Ships for free in 2–4 business days.
2006-2015 Lexus IS250 Upper Thermostat Housing 16031-31020
$49.99
In Stock
$49.99
Sale price
$49.99
Regular price
This new aftermarket upper water outlet and thermostat housing replaces 16031-31020 for compatible 2006-2015 Lexus IS250 models.
Estimated delivery between
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Compatible Models
We do our best to list all compatible models. Although this may be the part you need, your exact model may not appear below.
Compatible equipment / model
- Lexus IS250 2.5L V6 (2006-2015; verify production date and original housing)
- Lexus IS250 AWD and RWD applications using 16031-31020
Product Overview
Coolant odor, crust around the outlet, a wet engine valley, or a leak that appears after warm-up can point to a cracked housing or failed seal. Once hoses and nearby fittings are traced carefully, replacing the leaking upper outlet can restore a sealed coolant path.
This part belongs to a hot, pressurized system, so connector location, hose angles, sealing surfaces, and original number matter. It is not a cure for every temperature complaint; test the thermostat, water pump, radiator, fans, cap, and combustion leakage when symptoms call for it.
Key Features & Performance
- Replaces the upper coolant outlet on matching 2.5L applications
- Addresses cracks, warped sealing surfaces, and outlet leaks
- Application-shaped hose connections and mounting points
- New aftermarket service part
Replaces Part Numbers
- 16031-31020
- 1603131020
Common Uses
- Repairing coolant seepage around the upper outlet
- Replacing a brittle housing disturbed during cooling-system work
- Correcting a confirmed leak after a pressure test
Technical Specifications
- Product Type: Upper thermostat housing / water outlet
- Engine: 2.5L V6 compatible applications
- System: Engine cooling
- Condition: New aftermarket replacement
Installation & Fitment
- Let the engine cool completely and drain coolant safely
- Clean sealing surfaces without gouging them
- Compare every port, hose neck, and bolt location
- Use the correct seal and torque procedure
- Refill, bleed, pressure-test, and inspect for leaks
Compatibility Notice
Northline Parts does its best to list all known compatible models. The correct part may fit an application that is not shown above. Model year, production date, serial number, engine or equipment specification, installed options, and previous repairs can change fitment. Match the original part, reference number, dimensions, connectors, mounting points, and product photos before purchase.
Frequently Asked Questions
Q: Can this housing cause a slow coolant leak? A: Yes. Plastic housings and seals can age, crack, or warp, especially after repeated heat cycles.
Q: Does the thermostat come installed? A: Confirm included pieces from the listing photos; do not assume unpictured seals or thermostat components are supplied.
Q: Will this solve overheating? A: Only when the housing leak is the cause. Diagnose circulation, fans, radiator flow, and engine condition too.
Q: Is this an original-equipment part? A: No. This is a new aftermarket product. Brand names and part numbers are used only to identify compatible applications.
Part Summary
keywords: Lexus IS250 thermostat housing, 16031-31020 water outlet, 2006-2015 IS250 coolant leak, Lexus upper coolant housing, IS250 aftermarket thermostat outlet
Brand names, model numbers, and reference part numbers are used for identification and compatibility purposes only. Verify the original component, specifications, and application before purchase.