13 Cooling system parts are listed for the 2021 Isuzu NPR, in 4 part types, covering both the 5.2L L4 DIESEL Turbocharged and the 6.6L V8. Each one has a brand, a manufacturer part number and notes that say where it fits.
The cooling system system on the 2021 Isuzu NPR 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 (9 parts), Thermostat (2 parts) and Radiator (1 part). The other 1 part type covers the remaining 1 part.
The 2021 Isuzu NPR was sold with both the 5.2L L4 DIESEL Turbocharged and the 6.6L V8. 5 parts fit every engine; the other 8 are engine-specific. Each part shows which engine(s) it fits.
5 brands supply cooling system parts for the 2021 Isuzu NPR, led by PRESTONE (5 parts), VALVOLINE (4 parts) and GATES (2 parts), plus 2 more brands. Quality grades include Economy, Heavy Duty and Premium.
A "Popular" badge means the source catalog flagged the part as frequently chosen for the 2021 Isuzu NPR. 2 parts have it, including VALVOLINE ZXG051 (Coolant / Antifreeze) and PRESTONE AF2100 (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 2021 NPR engines | AF3055 | 🇺🇸 US 🇨🇦 CA | Prime YellowAll Vehicles | View on Amazon |
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PRESTONE Fits: all 2021 NPR engines | AF3100 | 🇺🇸 US 🇨🇦 CA | Prime Yellow - All VehiclesExtended Life | View on Amazon |
| VALVOLINE Fits: 5.2L L4 DIESEL Turbocharged | 719009 | 🇺🇸 US 🇨🇦 CA | Multi-Vehicle Yellow1 Gallon | View on Amazon |
Heavy Duty
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VALVOLINE Popular Fits: 5.2L L4 DIESEL Turbocharged | ZXG051 | 🇺🇸 US 🇨🇦 CA | G05 Yellow1 Gallon | View on Amazon |
| PRESTONE Fits: all 2021 NPR engines | AFC12100 | 🇺🇸 US 🇨🇦 CA | Command Nitrite Free Extended Life CoolantYellow Nitrite Free OAT | View on Amazon |
| VALVOLINE Fits: 5.2L L4 DIESEL Turbocharged | 846439 | 🇺🇸 US 🇨🇦 CA | HD Nitrite Free Extended Life Yellow1 Gallon | View on Amazon |
Premium
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PRESTONE Popular Fits: all 2021 NPR engines | AF2100 | 🇺🇸 US 🇨🇦 CA | All Vehicles10yr/300k mi | View on Amazon |
| PRESTONE Fits: all 2021 NPR engines | AFMAX | 🇺🇸 US 🇨🇦 CA | Max Universal1 Gallon | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VALVOLINE Fits: 5.2L L4 DIESEL Turbocharged | ZX001 | 🇺🇸 US 🇨🇦 CA | Original Green1 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.
9 Coolant / Antifreeze parts are listed for the 2021 Isuzu NPR, from PRESTONE and VALVOLINE. VALVOLINE ZXG051 carries the "Popular" badge. 5 parts fit every engine; the other 4 are engine-specific.
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 and VALVOLINE supply 2 parts: the catalog's value-priced group. A representative part number is PRESTONE AF3100.
The Heavy Duty section lists 3 options from VALVOLINE and PRESTONE — rated for severe service. VALVOLINE ZXG051 is listed in this group.
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 1 option from VALVOLINE — built to original-equipment specification. VALVOLINE ZX001 is listed in this group.
Part numbers include VALVOLINE ZXG051, PRESTONE AF3055 and PRESTONE AF3100, among others listed above.
Radiator
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| SPECTRA PREMIUM Fits: 5.2L L4 DIESEL Turbocharged | 20010707P | 🇺🇸 US 🇨🇦 CA | Aluminum Core with Plastic Tanks | 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 2021 Isuzu NPR — SPECTRA PREMIUM 20010707P.
Radiator Cap
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GATES Fits: 5.2L L4 DIESEL Turbocharged | 31336 | 🇺🇸 US 🇨🇦 CA | OE Type | 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.
One part is listed for the 2021 Isuzu NPR — GATES 31336.
Thermostat
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| ULTRA-POWER Fits: 6.6L V8 | 34198 | 🇺🇸 US 🇨🇦 CA | 190 DegreeIncludes Seal | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GATES Fits: 6.6L V8 | 34198 | 🇺🇸 US 🇨🇦 CA | OE Type | View on Amazon |
This table covers the thermostats that open the coolant circuit at the specified temperature. Typical signs include slow warm-up, a gauge that climbs in traffic, or heat that never quite arrives. Replace the housing gasket with the thermostat and bleed the system so a trapped air pocket does not cook the new part.
2 Thermostat parts for the 2021 Isuzu NPR come from 2 brands — ULTRA-POWER and GATES.
The Economy section: 1 option from ULTRA-POWER. ULTRA-POWER 34198 is listed in this group.
Standard Replacement: 1 part, from GATES. A representative part number is GATES 34198.
Listed part numbers: ULTRA-POWER 34198, plus the other parts above.
Buying Cooling System Parts for a 2021 Isuzu NPR
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 Thermostat .
Frequently Asked Questions
How many cooling system parts fit the 2021 Isuzu NPR?
Our catalog currently lists 13 cooling system parts for the 2021 Isuzu NPR across 4 subcategories and 5 brands, covering both the 5.2L L4 DIESEL Turbocharged and the 6.6L V8. Each part is matched to the engine(s) it fits.
Do cooling system parts differ between 2021 Isuzu NPR engines?
Some do. 5 parts fit every engine; the other 8 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 2021 Isuzu NPR?
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 2021 Isuzu NPR 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 2021 Isuzu NPR?
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 2021 Isuzu NPR
Cooling System Parts for Other Isuzu NPR Years
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