1981 Honda Civic Cooling System Parts

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. Read more

21 Coolant / Antifreeze parts are listed for the 1981 Honda Civic, from PEAK, PRESTONE, VALVOLINE and 2 other brands. FVP MV5050GAL carries the "Popular" badge. All of them fit every engine offered in the 1981 Civic.

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, FVP, PEAK, PRESTONE and 1 other brand supply 4 parts: the catalog's value-priced group. A representative part number is FVP MV5050GAL.

The Premium section lists 5 options from PRESTONE and PEAK — a step above OE specification in materials, tolerances or warranty terms. PRESTONE AF2100 is listed in this group.

The Standard Replacement section lists 11 options from PEAK, VALVOLINE, BECK/ARNLEY and 2 other brands — built to original-equipment specification. VALVOLINE ZXEL1 is listed in this group.

This table covers the adapters used to pressure-test this cooling system. Read more

3 Cooling System Tester Adapter parts are listed for the 1981 Honda Civic, from ACDELCO, GATES and MOTORAD. All of them fit every engine offered in the 1981 Civic.

Part numbers include ACDELCO 12A01, GATES 31413 and MOTORAD 3003.

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. Read more

7 Radiator Cap parts are listed for the 1981 Honda Civic, from GATES, MOTORAD, SKP and 1 other brand. GATES 31527 carries the "Popular" badge. All of them fit every engine offered in the 1981 Civic.

The Locking Replacement section lists 3 options from GATES, MOTORAD and SKP — grouped under the catalog's "Locking Replacement" designation — the notes column spells out what sets them apart. GATES 31511 is listed in this group.

The Standard Replacement section: 4 options from GATES, MOTORAD, CALORSTAT and 1 other brand. GATES 31527 is listed in this group.

Listed part numbers: GATES 31527, GATES 31511 and MOTORAD ST13, plus the other parts above.

This table covers the petcocks used to drain the radiator. Read more

This group shows a single part: DORMAN 490235.

This table covers the upper, lower and connecting hoses between radiator, engine and reservoir. Typical signs include swelling, cracks, a soft spot, or a leak at a clamp. Replace adjacent aged hoses while the system is drained — they share the same heat cycle. Read more

8 Radiator Hose parts for the 1981 Honda Civic come from 4 brands — GATES, ACDELCO, CONTINENTAL and 1 other brand. The "Popular" part is GATES 21228.

Listed part numbers: GATES 21228, ACDELCO 24116L and ACDELCO 26055X, plus the other parts above.

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. Read more

5 Temperature Sender / Sensor parts are listed for the 1981 Honda Civic, from ULTRA-POWER, BECK/ARNLEY, ROSTRA and 2 other brands. All of them fit every engine offered in the 1981 Civic.

Economy: 1 part, from ULTRA-POWER. A representative part number is ULTRA-POWER 1T1141.

The Standard Replacement section: 4 options from BECK/ARNLEY, ROSTRA, STANDARD MOTOR PRODUCTS and 1 other brand. BECK/ARNLEY 2010866 is listed in this group.

Part numbers include ULTRA-POWER 1T1141, BECK/ARNLEY 2010866 and ROSTRA 680090, among others listed above.

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. Read more

20 Thermostat parts for the 1981 Honda Civic come from 7 brands — MOTORAD, FACET, BECK/ARNLEY and 4 other brands. The "Popular" part is GATES 33488S. 19 parts fit every engine; the other 1 is engine-specific.

In the Heavy Duty grade, GATES and MOTORAD supply 2 parts: rated for severe service. A representative part number is GATES 33488S.

The Performance section lists 1 option from MOTORAD — engineered beyond original-equipment specification. MOTORAD 2040180 is listed in this group.

Premium: 2 parts, from MOTORAD. A representative part number is MOTORAD 7240180.

Standard Replacement: 15 parts, from FACET, MOTORAD, BECK/ARNLEY and 4 other brands. A representative part number is MOTORAD 240180.

This table covers the seals at the thermostat housing and water outlet. Typical signs include a wet housing, a drip after sitting, or fluid flung off a rotating shaft. Fix the surface the seal rides on. A new seal on a grooved shaft will leak again. Read more

14 Thermostat / Thermostat Housing / Water Outlet Seal parts are listed for the 1981 Honda Civic, from APEX, FEL-PRO, MOTORAD and 4 other brands. FEL-PRO 35316 carries the "Popular" badge. 10 parts fit every engine; the other 4 are engine-specific.

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. Read more

6 Water Pump parts for the 1981 Honda Civic come from 3 brands — FVP, US MOTOR WORKS and GMB.

The Economy section: 2 options from FVP and US MOTOR WORKS. FVP US9035 is listed in this group.

Standard Replacement: 2 parts, from FVP and GMB. A representative part number is FVP 1351080.

2 further parts sit outside the graded sections, with the same engine-level match.

This group includes FVP US9035 and FVP 1351080 and the remaining parts above.

This table covers the gaskets between the water pump and the block or housing. Typical signs include seepage at the joint, a burnt-oil smell, or a leak that appears only after a long drive. Clean both flanges and torque in the sequence the notes or the manual call for. Read more

One part is listed for the 1981 Honda Civic — APEX AWP3211.