Auto Parts & Repair: Performance demands precision

Your Cadillac is more than a luxury vehicle – it is a technologically advanced, high-performance machine. High-quality auto parts that are specifically designed, made, tested, and used for your auto repair will help keep that machine running at its peak.


Your dealer offers a full line of parts for your auto repair needs. The Certified Service experts know precisely which parts your Cadillac needs — depend on them to maintain and repair your Cadillac.

Understanding Cadillac Auto Repair: How Parts Work & Signs of Wear

Below you will find a part-by-part overview of all the major systems within your Cadillac, many of which that come backed by our Limited Lifetime Parts Warranty. Use the part description and signs of wear to better understand how to keep your Cadillac running in a manner that you’ve come to both expect and enjoy. When the time is right for auto repair service or if you ever have concerns, bring your vehicle back to your Cadillac dealer. Nobody knows auto repair for your Cadillac vehicle better.


HVAC & Engine Cooling Parts

Accumulator/Drier: (Limited Lifetime Parts Warranty Protection)
The accumulator in your vehicle gathers and stores liquid refrigerant until
it’s converted into a gas refrigerant.

Sign of wear:
Lack of or insufficient cooling in cabin

Compressor: (Limited Lifetime Parts Warranty Protection)
The compressor compresses refrigerant. The compression leads to a
change in the refrigerant’s boiling point, which helps create the cold air
that is delivered through the HVAC system.

Signs of wear:
Lack of or insufficient cooling
Excessive clicking sounds or unusual noises during A/C operation

Water Pump: (Limited Lifetime Parts Warranty Protection
The water pump is responsible for circulating engine coolant through the radiator and engine system to help maintain optimal engine operating temperatures.

Sign of wear:
Engine overheating
Leaking coolant

Condenser: (Limited Lifetime Parts Warranty Protection
The condenser cools refrigerant gas back into a liquid state.

Sign of wear:
Reduced cooling capacity in vehicle cabin due to physical damage or debris

Compressor Clutch:
A critical component of your HVAC system, the compressor clutch engages and disengages your compressor.

Signs of wear:
Reduced cooling in vehicle interior
Noise when running A/C system
Rubbing/grinding noise when A/C is off

Blower Motor:
Your vehicle’s blower motor drives air through the HVAC system and
into your cabin.

Signs of wear:
Lack of or diminished airflow through cabin vents
Unusual noises coming from blower motor

Engine Cooling Fan:
The engine cooling fan, located behind your radiator, draws cool outside
air through the condenser and radiator at low-speed operation to cool
the engine.

Signs of wear:
Engine overheats
Fan doesn’t turn
Poor A/C performance

Expansion Valve:
The expansion valve restricts the flow of refrigerant, allowing it to change
from a high-pressure liquid to a low-pressure gas, which provides the
cooling effect of A/C.

Sign of wear:
Lack of cooling in cabin

Warm air from inside your vehicle is delivered to your evaporator. Moisture and heat are then removed from the air and returned to your cabin.

Sign of wear:
Lack of cooling in cabin

Heater Core:
Hot engine coolant from the cooling system circulates through the heater
core to provide warm air to the passenger compartment.

Signs of wear:
Sweet smell coming from vents
Insufficient heat from vents
Wet carpet on passenger side

Engine coolant flowing through the radiator is cooled by wind and the
radiator fan, helping to keep the engine within proper operating

Signs of wear:
Leaking (often a bright green color)
Engine overheats
Sweet smell

The thermostat regulates the temperature of the engine coolant to
maintain proper engine operating temperature.

Signs of wear:
Engine overheats
Reduced fuel economy
Insufficient heat in cabin

Battery & Ignition Parts

Alternator/Generator: (Limited Lifetime Parts Warranty Protection)
Your vehicle’s alternator/generator provides power to electrical systems
and charges the battery while the vehicle is running.

Signs of wear:
Engine won’t turn over
Loss of battery power
Some loss of electrical power
Alternator warning light illuminates
Dim headlights

Ignition Coil: (Limited Lifetime Parts Warranty Protection)
The ignition coil increases voltage, creating a surge of energy within your vehicle’s electrical system in order to better ignite the air/fuel mixture within your engine.

Signs of wear:
Engine won’t start
Engine misfiring
Visible cracks in coil body

Ignition Modules:  (Limited Lifetime Parts Warranty Protection)
Later model vehicles with a distributor and coil pack use an ignition
module as a switch that, when engaged, supplies power to the coil, which
in turn creates the spark that ignites the air/fuel mixture.

Signs of wear:
Engine won’t start
Engine misfiring

Ignition Wire Set: (Limited Lifetime Parts Warranty Protection)
This specialized wire set carries voltage from the ignition coil, electronic
coil pack, or distributor to the spark plugs.

Signs of wear:
Difficult engine starting
Decreased fuel economy

Starting Motor & Solenoid: (Limited Lifetime Parts Warranty Protection)
When starting the engine, the solenoid is energized, which engages the
starter pinion into the flywheel, while the starter motor drives the pinion to crank the engine.

Signs of wear:
Poor starting qualities, including repeated starting attempts
Grinding while cranking
Intermittent starter engagement while trying to start the engine

Your car’s battery supplies and stores electrical energy from the alternator
when the vehicle’s engine is running. The car battery provides energy to
start the engine, plus supplies power to accessories when the engine is
not running. For the best combination of longevity, power, and price, we
proudly offer a wide range of ACDelco batteries.

Signs of wear:
Slow cranking
Weak/dim lights while cranking

Distributor Cap:
Vehicles equipped with a distributor use the distributor cap to act as a hub
for spark plug and ignition coil wires.

Signs of wear:
Inability to start engine
Poor starting qualities
Decreased fuel economy

Spark Plug:
Spark plugs provide the spark that ignites the air/fuel mixture within an engine’s cylinders.

Signs of wear:
Lack of power
Sluggish acceleration
Poor fuel economy

Fuel & Engine Emissions Parts

Modular Fuel Pump/Sender: (Limited Lifetime Parts Warranty Protection)
This two-part component delivers fuel from your tank to the fuel injectors
while monitoring and sending fuel-level information to your fuel gauge.

Signs of wear:
Difficulty starting engine
Slow acceleration qualities
Intermittent power loss
Inaccurate fuel-gauge reading

Engine Control Module (ECM):
This module monitors and synchronizes the operation of the ignition,
emission, and fuel-injection systems. All sensors input information to the
ECM to constantly adjust the air-fuel mixture for optimum emissions,
drivability, and performance.

Signs of wear:
Engine won’t start
Reduced or loss of engine power
“Service Engine Soon” light illuminates

Exhaust Gas Recirculation (EGR) Valve:
The EGR valve recirculates some of the engine’s exhaust gas back into the intake manifold to be reburned, reducing emissions.

Signs of wear:
Rough-running engine
Engine hesitation or stalling
“Service Engine Soon” light illuminates

Fuel Injector:
The fuel injector sprays a fine mist of fuel into a vehicle’s intake manifold
or cylinders a fraction of a second before the spark plug ignites it.

Signs of wear:
Sluggish engine performance
Poor acceleration
“Service Engine Soon” light illuminates

Mass Air Flow Sensor:
This sensor measures the amount of air entering the engine.

Signs of wear:
Engine hesitation
Decline in engine performance
“Service Engine Soon” light illuminates

Oxygen Sensor:
The oxygen sensor measures the amount of leftover oxygen from the combustion process in the exhaust.

Signs of wear:
Rough-running engine
Poor fuel economy
“Service Engine Soon” light illuminates

Engine Coolant Temperature Sensor:
Constantly measures the engine’s coolant temperature.

Signs of wear:
Cooling fan(s) on high all the time
Poor fuel economy
“Service Engine Soon” light illuminates

Intake Air Temperature Sensor:
Constantly measures the temperature of the incoming air to the engine.

Signs of wear:
Rough-running engine
Poor fuel economy
“Service Engine Soon” light illuminates

Humidity Sensor:
Constantly measures the humidity of the incoming air to the engine.

Sign of wear:
“Service Engine Soon” light illuminates

Knock Sensor:
Constantly measures the spark knock from the engine so the ECM
can adjust the ignition timing to reduce it.

Signs of wear:
Lack of power
“Service Engine Soon” light illuminates

Throttle Position Sensor (throttle body):
Constantly measures the opening of the throttle body as you depress the accelerator.

Sign of wear:
“Reduced Engine Power” light illuminates

Accelerator Pedal Position Sensor:
Constantly measures the amount the accelerator is depressed so the ECM
can open the throttle proportionately to increase acceleration.

Sign of wear:
“Reduced Engine Power” light illuminates

Fuel Pressure Sensor:
Constantly measures the fuel pressure in the fuel rail so the ECM can
maintain the pressure at optimum levels.

Signs of wear:
Ticking noise from engine
“Service Engine Soon” light illuminates

Fuel Composition Sensor:
On vehicles equipped to run on E85 ethanol, this sensor constantly
measures the amount of ethanol in the fuel.

Sign of wear:
“Service Engine Soon” light illuminates

Positive Crankcase Ventilation (PCV) Valve:
Your vehicle’s PCV valve is designed to regulate unspent combustion gases so they can be burned in the engine.

Signs of wear:
Engine runs rough or unexpectedly stalls
“Service Engine Soon” light illuminates

Catalytic Converter(s):
The catalytic converter is an emission control device added to the engine exhaust system in order to reduce hydrocarbons, carbon monoxide, and oxides of nitrogen pollutants from the exhaust gas.

Signs of wear:
Exhaust is louder
Rotten-egg smell

Some exhaust systems are equipped with a resonator. The resonator,
located either before or after the muffler, allows the use of mufflers with
less back pressure. Resonators are used when vehicle characteristics
require specific exhaust tuning.

Signs of wear:
Exhaust is louder
Clunking noise in rear of vehicle

Muffler & Tailpipe:
The exhaust muffler reduces the noise levels of the engine exhaust by the
use of tuning tubes. The tuning tubes create channels inside the exhaust
muffler that lower the sound levels created by the combustion of the engine.
The tailpipe carries the exhaust gases from the muffler to the rear of your

Signs of wear:
Exhaust is louder
Clunking noise in rear of vehicle

Driveline/Powertrain Parts

Wheel Bearing: (Limited Lifetime Parts Warranty Protection)
The wheel bearing is mounted on a wheel hub, which in turn is connected
to the axle. The bearings reduce friction and increase your control of the vehicle as the wheel turns over the surface of the road.

Signs of wear:
Whining or squealing noises
Looseness or roughness felt in the steering-wheel

CV Joint/Boot:
The CV boot protects the CV joint (in front-wheel-drive automatic transaxle
vehicles) from harmful moisture, sand, dust, and other roadway debris.
If the boot is worn or damaged, these particles can eat away at the
CV joint, potentially causing the need to replace the CV joint or even
a half axle.

Signs of wear:
Lubricant leak
Clicking sounds during turning
Clunks during acceleration
Front-end vibrations

The engine is the heart of your vehicle. Most engines use combustion
(igniting an air/fuel mixture to create mechanical energy) to create power
that is delivered to the wheels, which in turn propels the vehicle.

Signs of wear:
Rough running
High oil or fuel consumption
Visible smoke while engine is running

The transmission/transaxle in your vehicle uses a combination of
hydraulics and gears to transfer power from the engine to the wheels.
Transmissions are utilized in rear-wheel-drive applications and transaxles
on front-wheel-drive.

Signs of wear:
Noticeable transmission/transaxle slippage
Lack of acceleration
Transmission fluid emits a burning odor

Differential/Rear Axle:
The differential receives power from the drive shaft and delivers power to
rear-drive wheels through a series of gears.

Signs of wear: 
Clanking noise
Whining or humming noise at steady speed or during coast down

This round, multi-toothed disc connects the engine, clutch system, and automatic transmission.

Signs of wear:
Noticeable transmission slippage
Lack of acceleration
Failure to engage
Erratic transmission operation

Manual vehicles use this combination of components to engage and
disengage the engine to and from the transmission for changing gears.

Signs of wear:
Clutch slippage
Clutch engage failure

Suspension Parts

Shocks & Struts: (Limited Lifetime Parts Warranty Protection
The ride and handling system supports your vehicle’s weight, keeps the wheels in contact with the road, and helps provide a comfortable ride.

Signs of wear:
Excessive ball joint play
Leaking oil along the shock body
Broken mounts or mounting hardware
Worn or missing bushings
Excessive vehicle bounce
Cupped tire wear

Shock Absorber:  (Limited Lifetime Parts Warranty Protection
The shock absorbers on your vehicle minimize spring bounce, helping to
keep wheels in contact with the road and providing a smoother ride.

Signs of wear:
Excessive vehicle bounce
Cupped tire wear

Ball Joint:
The ball joint is a pivot point for the wheel assembly, allowing the wheels
to turn and move up and down with the suspension.

Signs of wear:
Rough ride
Play in steering-wheel
Slow or stiff steering-wheel return
Excessive tire wear on one side

Strut Mount/Bearing:
The strut mount helps improve strut operation by absorbing energy and
restoring smooth steering, while the bearing allows the strut to turn with
the wheels while steering.

Signs of wear:
Suspension noise
Uneven tire wear
Steering-wheel does not easily return to center position

Coil Springs:
Your suspension system’s coil springs support the weight of your vehicle
and maintain vehicle ride height.

Signs of wear:
Low vehicle ride height
Rough, unstable, or uncontrollable ride
Excessive tire wear on one side

The bushings attached to the suspension system provide a cushioned link between control arms and chassis.

Signs of wear:
Excessive steering-wheel play
Hard steering
Irregular tire wear

Control Arm:
Control arms join wheel hubs to the vehicle frame, allowing for a full range
of motion while maintaining proper wheel alignment.

Signs of wear:
Uneven tire wear
Suspension noise or misalignment
Steering-wheel wobble or vibration


Steering Parts

Power Steering:
The hydraulic power-steering pump is a constant displacement pump that provides hydraulic pressure and flow for the power-steering gear. The hydraulic power-steering pump is belt-driven off your engine.

Signs of wear:
Fluid leakage
Difficult low-speed steering
Whining noise while turning
Steering-wheel wobble
Pump housing leakage

This steering assembly uses a long steel bar that is meshed with a pinion
gear and connected to rods that turn the front wheels. The rack-and-pinion
can be hydraulically assisted by a power-steering pump or electrically

Signs of wear:
Excessive play in steering-wheel
Steering-wheel vibration
Unusual noises while turning the wheel

Idler Arm:
The idler arm in your vehicle acts as a pivot point to the steering linkage assembly.

Sign of wear:
Irregular tire wear, such as feathering or scrubbing

Pitman Arm:
On vehicles that utilize a steering gear, the pitman arm connects the
steering gear and steering linkage.

Sign of wear:
“Wandering” and excessive steering with little directional change

Tie-Rod End:
The tie-rod end connects or ties the steering linkage to the wheel hub assembly, allowing for the transfer of motion to the wheel.

Signs of wear:
Rough or stuttered steering
Play in steering-wheel
Inner or outer tire-edge wear



V-Ribbed Serpentine Belt:
This belt transfers power from the crankshaft to the alternator, water pump,
air conditioning compressor, and power-steering pump (if applicable).

Signs of wear:
Slipping and/or squealing belt
Dimming headlights while driving
Loss of battery charging

Timing Chain/Belt:
Your vehicle’s timing chain/belt synchronizes the engine’s camshaft and crankshaft.

Signs of wear:
Engine stops
Engine backfires

Air Conditioning Hose:
Refrigerant stored under high pressure is transferred from your vehicle’s evaporator in the engine compartment to the condenser in front of the

Sign of wear:
A/C inoperative

Heater Hose:
The heater hose within your vehicle routes the hot engine coolant to the
heater core to heat the cabin.

Signs of wear:
Coolant leak
Cracking/hardening/brittleness of hose

Radiator Hose:
The radiator hose moves coolant from the engine to the radiator to be

Signs of wear:
Elevated engine temperature
Coolant leak
Cracking/hardening/brittleness of hose
“Check Engine” light illuminates

Engine Air Filters:
These filters prevent harmful debris from entering your engine.

Signs of wear:
Sluggish acceleration
Decreased fuel efficiency

Oil Filter:
Your vehicle’s oil filter cleanses engine oil to help reduce wear on the
engine’s internal components.

Signs of wear:
Oil leaks
Burning oil smell

Automatic Transmission Filter:
This filter keeps certain abrasive particles in the transmission fluid from reaching the transmission’s internal components.

Signs of wear:
Late shifts
Slipping in and out of gear

In-Line Fuel Filter:
This filter is designed to trap fuel contaminants before they enter the
engine’s fuel-delivery system.

Signs of wear:
Lack of power
Vehicle will not start
Vehicle only runs in idle or low speeds

Cabin Air Filter:
Cabin air filters prevent a majority of airborne particles from entering the cabin.

Sign of wear:
Decreased climate control (heating and A/C) airflow