The 2025 Kia K4 has 19 cooling system parts with verified fitment on this page — 6 part types and 12 brands, covering both the 1.6L L4 Turbocharged and the 2.0L L4. Each part includes a manufacturer part number and application notes.
The cooling system system on the 2025 Kia K4 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 (6 parts), Radiator Cap (4 parts) and Temperature Sender / Sensor (4 parts). The other 3 part types cover the remaining 5 parts.
The 2025 Kia K4 was sold with both the 1.6L L4 Turbocharged and the 2.0L L4. 6 parts fit every engine; the other 13 are engine-specific. Each part shows which engine(s) it fits.
12 brands supply cooling system parts for the 2025 Kia K4, led by PRESTONE (4 parts), MOTORAD (3 parts) and GATES (2 parts), plus 9 more brands. Quality grades include Standard Replacement, Economy and Premium.
A "Popular" badge means the source catalog flagged the part as frequently chosen for the 2025 Kia K4. 2 parts have it, including PRESTONE AF2100 (Coolant / Antifreeze) and VALVOLINE 861398 (Coolant / Antifreeze). Each part number opens a page with every vehicle that part fits.
Coolant / Antifreeze
Compatible With All Colors
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PRESTONE Fits: all 2025 K4 engines | AF3055 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Prime YellowAll Vehicles | View on Amazon |
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PRESTONE Fits: all 2025 K4 engines | AF3100 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Prime Yellow - All VehiclesExtended Life | View on Amazon |
Premium
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PRESTONE Popular Fits: all 2025 K4 engines | AF2100 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | All Vehicles10yr/300k mi | View on Amazon |
| PRESTONE Fits: all 2025 K4 engines | AFMAX | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Max Universal1 Gallon | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VALVOLINE Popular Fits: all 2025 K4 engines | 861398 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Asian Vehicle Blue1 Gallon | View on Amazon |
| PENTOSIN Fits: all 2025 K4 engines | 8115209 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Pentofrost A41 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.
6 Coolant / Antifreeze parts are listed for the 2025 Kia K4, from PRESTONE, VALVOLINE and PENTOSIN. PRESTONE AF2100 carries the "Popular" badge. All of them fit every engine offered in the 2025 K4.
The Compatible With All Colors section lists 1 option from PRESTONE — grouped under the catalog's "Compatible With All Colors" designation — the notes column spells out what sets them apart. PRESTONE AF3055 is listed in this group.
In the Economy grade, PRESTONE supplies 1 part: the catalog's value-priced group. A representative part number is PRESTONE AF3100.
The Premium section lists 2 options from PRESTONE — a step above OE specification in materials, tolerances or warranty terms. PRESTONE AF2100 is listed in this group.
The Standard Replacement section lists 2 options from VALVOLINE and PENTOSIN — built to original-equipment specification. VALVOLINE 861398 is listed in this group.
This group includes PRESTONE AF2100, PRESTONE AF3055 and PRESTONE AF3100 and the remaining parts above.
Coolant Reservoir Cap
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| MOTORAD Fits: 2.0L L4 | T153 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Standard | 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: MOTORAD T153.
Radiator
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| KOYORAD Fits: 2.0L L4 | A13939 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon |
This table covers the radiators that dump engine heat to airflow through the core. Typical signs include overheating in traffic, a wet core, or coolant that disappears with no puddle. Replace the cap if it cannot hold the rated pressure, and bleed the system after the swap.
One part is listed for the 2025 Kia K4 — KOYORAD A13939.
Radiator Cap
Locking Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| MOTORAD Fits: 2.0L L4 | ST16R | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Safety LeverIndicator Markings Color: Blue, Red | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| CALORSTAT Fits: 2.0L L4 | RC0027 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Includes 2 sealsMetallic | View on Amazon |
| GATES Fits: 2.0L L4 | 31336 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | OE Type | View on Amazon |
| MOTORAD Fits: 2.0L L4 | T16R | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | StandardIndicator Markings Color: Silver | 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.
4 Radiator Cap parts are listed for the 2025 Kia K4, from MOTORAD, CALORSTAT and GATES.
The Locking Replacement section lists 1 option from MOTORAD — grouped under the catalog's "Locking Replacement" designation — the notes column spells out what sets them apart. MOTORAD ST16R is listed in this group.
The Standard Replacement section: 3 options from CALORSTAT, GATES and MOTORAD. CALORSTAT RC0027 is listed in this group.
Part numbers include MOTORAD ST16R, CALORSTAT RC0027 and GATES 31336, among others listed above.
Temperature Sender / Sensor
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GPD Fits: 1.6L L4 Turbocharged | 1816395 | 🇺🇸 US 🇨🇦 CA | Lower Front, Lower Right | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| STANDARD MOTOR PRODUCTS Fits: 1.6L L4 Turbocharged | TX337 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Water Pump | View on Amazon |
| WELLS Fits: 1.6L L4 Turbocharged | 5S17563 | 🇺🇸 US 🇨🇦 CA | Lower | View on Amazon |
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| STANDARD MOTOR PRODUCTS Fits: 2.0L L4 | TX359 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Engine BlockOn Side of Block | 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.
4 Temperature Sender / Sensor parts are listed for the 2025 Kia K4, from STANDARD MOTOR PRODUCTS, GPD and WELLS.
Economy: 1 part, from GPD. A representative part number is GPD 1816395.
The Standard Replacement section: 2 options from STANDARD MOTOR PRODUCTS and WELLS. STANDARD MOTOR PRODUCTS TX337 is listed in this group.
1 ungrouped part is not assigned to a grade, with the same engine-level match.
This group includes GPD 1816395, STANDARD MOTOR PRODUCTS TX337 and WELLS 5S17563 and the remaining parts above.
Water Pump
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| FVP Fits: 1.6L L4 Turbocharged | 1463020 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Mounting Hardware Included: YES | View on Amazon |
| GATES Fits: 1.6L L4 Turbocharged | 41237 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon | |
| GMB Fits: 1.6L L4 Turbocharged | 1463020 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | 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.
3 Water Pump parts for the 2025 Kia K4 come from 3 brands — FVP, GATES and GMB.
This group includes FVP 1463020 and GATES 41237 and the remaining parts above.
Buying Cooling System Parts for a 2025 Kia K4
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.
- Match the engine first. Some cooling system parts fit every engine; others are engine-specific. Each row shows which engine(s) it fits.
- 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 Radiator Cap .
Frequently Asked Questions
How many cooling system parts fit the 2025 Kia K4?
Our catalog currently lists 19 cooling system parts for the 2025 Kia K4 across 6 subcategories and 12 brands, covering both the 1.6L L4 Turbocharged and the 2.0L L4. Each part is matched to the engine(s) it fits.
Do cooling system parts differ between 2025 Kia K4 engines?
Some do. 6 parts fit every engine; the other 13 are engine-specific. Each row (and the filter at the top) shows which. If you're unsure which engine you have, check the emissions label under the hood or the 8th character of your VIN.
What are the signs of cooling system problems on a 2025 Kia K4?
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 2025 Kia K4 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 2025 Kia K4?
First match the engine — each row shows which engine(s) the part fits. 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 2025 Kia K4
Cooling System Parts for Other Kia K4 Years
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