This page lists 14 cooling system parts for the 2026 Lexus RX350H, across 5 part types, covering the 2.5L L4 ELECTRIC/GAS engine. Every part shows its brand, manufacturer part number and fitment notes.
The cooling system system on the 2026 Lexus RX350H keeps operating temperature in the narrow band the engine was designed for, from radiator and water pump to thermostat and hoses. The largest groups are Coolant / Antifreeze (5 parts), Water Pump (4 parts) and Radiator Cap (2 parts). The other 2 part types cover the remaining 3 parts.
The 2026 Lexus RX350H came with a single engine, the 2.5L L4 ELECTRIC/GAS, and every part is verified against it.
11 brands supply cooling system parts for the 2026 Lexus RX350H, led by VALVOLINE (2 parts), GATES (2 parts) and US MOTOR WORKS (2 parts), plus 8 more brands. Quality grades include Standard Replacement and Heavy Duty.
A "Popular" badge means the source catalog flagged the part as frequently chosen for the 2026 Lexus RX350H. 1 part has it: AISIN ACT002 (Coolant / Antifreeze). Each part number opens a page with every vehicle that part fits.
Coolant / Antifreeze
Heavy Duty
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PRESTONE | AFC12100 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Command Nitrite Free Extended Life CoolantYellow Nitrite Free OAT | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| AISIN Popular | ACT002 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | PinkHOAT | View on Amazon |
| PENTOSIN | 8115209 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Pentofrost A41 Gallon | View on Amazon |
| VALVOLINE | 675130 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Asian Vehicle Red1 Gallon | View on Amazon |
| VALVOLINE | 898406 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Hybrid Vehicle1 Gallon | View on Amazon |
This table covers the engine coolants and antifreeze formulations specified for this cooling system. Typical signs include a rising temperature gauge, rusty or sludged coolant, or a heater that blows cold. Use the chemistry named in the notes. Mixing silicate, OAT and HOAT formulas can gel in the radiator.
5 Coolant / Antifreeze parts are listed for the 2026 Lexus RX350H, from VALVOLINE, PRESTONE, AISIN and 1 other brand. AISIN ACT002 carries the "Popular" badge.
The Heavy Duty section lists 1 option from PRESTONE — rated for severe service. PRESTONE AFC12100 is listed in this group.
The Standard Replacement section lists 4 options from VALVOLINE, AISIN and PENTOSIN — built to original-equipment specification. AISIN ACT002 is listed in this group.
Listed part numbers: AISIN ACT002, PRESTONE AFC12100 and PENTOSIN 8115209, plus the other parts above.
Coolant Reservoir Cap
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GATES | 31541 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | OE TypeThreaded (Closed System) - (SAE Range 18-20 psi) | View on Amazon |
This table covers the caps on the overflow / expansion tank. Typical signs include a leak at the neck, a cap that will not hold pressure, or a missing tether. Match the pressure rating or thread in the notes — radiator, reservoir and fuel caps are not interchangeable.
This group shows a single part: GATES 31541.
Radiator Cap
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GATES | 31411 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | OE Type | View on Amazon |
| SKP | SK10241 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Pressure Rating 13 psi | View on Amazon |
This table covers the caps that hold system pressure at the radiator or reservoir neck. Typical signs include a leak at the neck, a cap that will not hold pressure, or a missing tether. Match the pressure rating or thread in the notes — radiator, reservoir and fuel caps are not interchangeable.
2 Radiator Cap parts are listed for the 2026 Lexus RX350H, from GATES and SKP.
Listed part numbers: GATES 31411 and SKP SK10241.
Temperature Sender / Sensor
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| NISSENS | 207139 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Base Model or Luxury or Premium or Premium+ | View on Amazon |
| STANDARD MOTOR PRODUCTS | TX319 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon |
This table covers the senders that report coolant temperature to the gauge or ECU. Typical signs include a gauge that sits on empty or overheat, or a lamp that does not match what the engine is doing. Rule out the cluster and the wiring before replacing the sender.
2 Temperature Sender / Sensor parts are listed for the 2026 Lexus RX350H, from NISSENS and STANDARD MOTOR PRODUCTS.
Listed part numbers: NISSENS 207139 and STANDARD MOTOR PRODUCTS TX319.
Water Pump
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| BECK/ARNLEY | 1312557 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Except Japan Built Vehicle Part | View on Amazon |
| FVP | US8233 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Base Model or Luxury or Premium or Premium+ | View on Amazon |
| US MOTOR WORKS | US8233 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Base Model or Luxury or Premium or Premium+ | View on Amazon |
| US MOTOR WORKS | US82332 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Includes Back Housing | View on Amazon |
This table covers the pumps that circulate coolant through the block and radiator. Typical signs include coolant at the weep hole, pulley play, or a growl from the front of the engine. Replace the thermostat and refill with the specified coolant whenever the pump comes off.
4 Water Pump parts for the 2026 Lexus RX350H come from 3 brands — US MOTOR WORKS, BECK/ARNLEY and FVP.
Listed part numbers: BECK/ARNLEY 1312557 and FVP US8233, plus the other parts above.
Buying Cooling System Parts for a 2026 Lexus RX350H
On this vehicle, the cooling system system keeps operating temperature in the narrow band the engine was designed for, from radiator and water pump to thermostat and hoses.
- Confirm you have the 2.5L L4 ELECTRIC/GAS engine — every part on this page is matched to it.
- Read the notes on each row for position, trim and spec qualifiers before you order.
- Where labor overlaps, replace the thermostat and refill with fresh coolant whenever you change a water pump or radiator; original hoses on an older vehicle are on borrowed time.
- Cross-reference the manufacturer part number against your old part or a service-manual listing.
Start with the largest groups on this page: Coolant / Antifreeze and Water Pump .
Frequently Asked Questions
How many cooling system parts fit the 2026 Lexus RX350H?
Our catalog currently lists 14 cooling system parts for the 2026 Lexus RX350H across 5 subcategories and 11 brands, covering the 2.5L L4 ELECTRIC/GAS engine. Each part is matched to the engine(s) it fits.
What are the signs of cooling system problems on a 2026 Lexus RX350H?
Common symptoms include a rising temperature gauge in traffic, sweet-smelling steam, crusty deposits around hose clamps, or a heater that blows cold. If you notice any of these, identify the affected subcategory above and cross-reference the part numbers listed.
What should I replace at the same time?
Where labor overlaps, replace the thermostat and refill with fresh coolant whenever you change a water pump or radiator; original hoses on an older vehicle are on borrowed time.
What do the market flags (US, CA, MX) on each part mean?
They show the market for which the manufacturer published application data for that part — where the vehicle was first sold, not where the part was made. If your 2026 Lexus RX350H was originally sold in the US, the safest choice is a part marked for the US market.
How do I make sure a part fits my 2026 Lexus RX350H?
Every part on this page is matched to the 2.5L L4 ELECTRIC/GAS engine. Then replace coolant with the exact specification the manufacturer calls for — mixing chemistries can gel and block small passages. The notes column carries position and trim qualifiers where they apply.
Other Parts for the 2026 Lexus RX350H
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Manufacturer names, model designations and part numbers are used for identification and fitment reference only. AutoFactsDB is an independent catalog and is not affiliated with, endorsed by, or sponsored by any vehicle manufacturer displayed on this page.