2008 Cadillac STS 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

16 Coolant / Antifreeze parts are listed for the 2008 Cadillac STS, from PRESTONE, PEAK, VALVOLINE and 3 other brands. FVP MV5050GAL carries the "Popular" badge. All of them fit every engine offered in the 2008 STS.

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 4 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 7 options from VALVOLINE, PRESTONE, ACDELCO and 2 other brands — built to original-equipment specification. ACDELCO 105027 is listed in this group.

This table covers the Coolant Bleed Hose fittings. Read more

One part is listed for the 2008 Cadillac STS — GM GENUINE 12589732.

This table covers the hard pipes and extra hoses in the coolant circuit. Read more

7 Coolant Hose / Pipe parts are listed for the 2008 Cadillac STS, from GATES, GM GENUINE, CONTINENTAL and 2 other brands. CONTINENTAL 61267 carries the "Popular" badge. 1 part fits every engine; the other 6 are engine-specific.

This group includes CONTINENTAL 61267, GATES 23133 and ACDELCO 20149S and the remaining parts above.

This table covers the seals at the Coolant Hose / Pipe. 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

2 Coolant Hose / Pipe Seal parts for the 2008 Cadillac STS come from 2 brands — ELRING and GM GENUINE. 1 part fits every engine; the other 1 is engine-specific.

Listed part numbers: ELRING 943630 and GM GENUINE 12623519.

This table covers the seals at the Coolant Hose Connector / Flange. 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

This group shows a single part: ELRING 943020.

This table covers the overflow / expansion tanks that hold extra coolant. Read more

2 Coolant Reservoir parts for the 2008 Cadillac STS come from 2 brands — DORMAN and SKP. Every part fits all 3 engine options (3.6L V6, 4.4L V8 Supercharged and 4.6L V8).

Part numbers include DORMAN 603141 and SKP SK603141.

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. Read more

4 Coolant Reservoir Cap parts for the 2008 Cadillac STS come from 3 brands — MOTORAD, AUTOTECNICA and GM GENUINE. 3 parts fit every engine; the other 1 is engine-specific.

This group includes AUTOTECNICA GM0613026, GM GENUINE 15076936 and MOTORAD T46 and the remaining parts above.

This table covers the seals at the Coolant Reservoir. 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

One part is listed for the 2008 Cadillac STS — GM GENUINE 12623461.

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

4 Cooling System Tester Adapter parts are listed for the 2008 Cadillac STS, from GATES and MOTORAD. 2 parts fit every engine; the other 2 are engine-specific.

This group includes GATES 31431, GATES 31391 and MOTORAD 3128 and the remaining parts above.

This table covers the Hose clamps. Read more

One part is listed for the 2008 Cadillac STS — GM GENUINE 11518519.

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. Read more

24 Radiator parts are listed for the 2008 Cadillac STS, from OSC, GPD, AGILITY and 8 other brands. FAMOUS BRAND 438175 carries the "Popular" badge. 2 parts fit every engine; the other 22 are engine-specific.

Economy: 8 parts, from GPD, FAMOUS BRAND, ULTRA-POWER and 1 other brand. A representative part number is FAMOUS BRAND 438175.

The Standard Replacement section: 16 options from OSC, AGILITY, DENSO and 4 other brands. DENSO 2219240 is listed in this group.

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

2 Radiator Cap parts are listed for the 2008 Cadillac STS, from ACDELCO and GATES. 1 part fits every engine; the other 1 is engine-specific.

This group includes ACDELCO RC116 and GATES 31532.

This table covers the fan assemblies (and clutches, where listed) that pull air through the radiator. Read more

13 Radiator Fan Assembly parts for the 2008 Cadillac STS come from 7 brands — DORMAN, GPD, TECHPRO and 4 other brands. The "Popular" part is DORMAN 620957. 2 parts fit every engine; the other 11 are engine-specific.

The Economy section: 7 options from DORMAN, GPD and TECHPRO. DORMAN 620957 is listed in this group.

Standard Replacement: 6 parts, from FOUR SEASONS, VDO / CONTINENTAL, TYC and 1 other brand. A representative part number is FOUR SEASONS 76358.

This table covers the Radiator Fan blades. Typical signs include chatter, streaks, or a skip at the top of the stroke. Confirm left and right lengths in the notes — they are often different. Read more

This group shows a single part: GM GENUINE 19129773.

This table covers the Radiator Fan clutches. Typical signs include slip at highway speed, chatter on takeoff, or a pedal that stays low. Resurface or replace the flywheel with the clutch — a heat-checked flywheel wastes the new disc. Read more

7 Radiator Fan Clutch parts are listed for the 2008 Cadillac STS, from FVP, HAYDEN, US MOTOR WORKS and 3 other brands. HAYDEN 2982 carries the "Popular" badge. 2 parts fit every engine; the other 5 are engine-specific.

Part numbers include HAYDEN 2982, US MOTOR WORKS 22632 and FOUR SEASONS 46132, among others listed above.

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

22 Radiator Hose parts for the 2008 Cadillac STS come from 4 brands — GATES, ACDELCO, DAYCO and 1 other brand. The "Popular" part is DAYCO 72650.

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

39 Temperature Sender / Sensor parts are listed for the 2008 Cadillac STS, from STANDARD MOTOR PRODUCTS, NTK, WALKER PRODUCTS and 15 other brands. NTK EF0008 carries the "Popular" badge. Grades run from Economy through Standard Replacement; Standard Replacement is the most populated section, led by STANDARD MOTOR PRODUCTS, WELLS, NTK and 9 other brands.

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

13 Thermostat parts for the 2008 Cadillac STS come from 7 brands — MOTORAD, GATES, AISIN and 4 other brands. The "Popular" part is GATES 33808.

In the Heavy Duty grade, MOTORAD supplies 1 part: rated for severe service. A representative part number is MOTORAD 5339180.

Premium: 1 part, from MOTORAD. A representative part number is MOTORAD 7339180.

Standard Replacement: 5 parts, from GATES, MOTORAD, AISIN and 2 other brands. A representative part number is GATES 33808.

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

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

37 Thermostat / Thermostat Housing / Water Outlet Seal parts are listed for the 2008 Cadillac STS, from FEL-PRO, GM GENUINE, MAHLE / CLEVITE and 6 other brands. FEL-PRO 35858 carries the "Popular" badge. The notes list position, dimensions and spec qualifiers wherever the manufacturer distinguishes between variants.

This table covers the housings and outlets the thermostat sits in. Read more

This group shows a single part: ACDELCO 12706566.

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

28 Water Pump parts for the 2008 Cadillac STS come from 16 brands — FVP, GATES, GM GENUINE and 13 other brands. The "Popular" part is BECK/ARNLEY 1312378. They are grouped as Economy and Standard Replacement, with Standard Replacement the largest group at 16 parts from GATES, GM GENUINE, GMB and 5 other brands.

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

8 Water Pump Gasket parts are listed for the 2008 Cadillac STS, from APEX, VICTOR REINZ, FEL-PRO and 3 other brands. FEL-PRO 35859 carries the "Popular" badge.

Listed part numbers: FEL-PRO 35859, GM GENUINE 2512052 and APEX AWP3231, plus the other parts above.

This table covers the Water Pump pulleys. Typical signs include a growl or chirp that follows engine speed, or a pulley that will not spin freely by hand. Spin each pulley with the belt off. Roughness or play means replace it with the belt. Read more

One part is listed for the 2008 Cadillac STS — GM GENUINE 12611587.

This table covers the Water Pump Seal O-rings. Typical signs include a seep at a fitting or a housing that weeps after a service. Lube the new O-ring with the fluid it will see, and do not roll it into the groove. Read more

3 Water Pump Seal / O-Ring parts for the 2008 Cadillac STS come from 3 brands — FEL-PRO, GM GENUINE and MAHLE / CLEVITE.

This group includes FEL-PRO 35860, GM GENUINE 12691259 and MAHLE / CLEVITE K32433.