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<h2>What is an engine thermostat?</h2>
&nbsp;While all engines can become too hot, if your thermostat isn't working correctly, your engine's well-being is at serious risk. The engine thermostat, often simply referred to as a thermostat, regulates the engine's operating temperature within an optimal range (typically around 195 to 220 degrees Fahrenheit).
<h2>How does a car thermostat work?</h2>
As a temperature-sensitive valve within the cooling system, a car thermostat responds to changes in coolant temperature. Understanding how it works by the following breakdown steps:
<ul>
<li>Closed position (cold start)</li>
</ul>
Initially closed to help the engine warm up quickly.
<ul>
<li>Heating up</li>
</ul>
The engine generates heat during operation.
<ul>
<li>Opening the thermostat</li>
</ul>
A temperature-sensitive element (usually wax) causes the thermostat to open gradually.
<ul>
<li>Coolant flow</li>
</ul>
When open, coolant flows from the engine to the radiator.
<ul>
<li>Maintaining optimal temperature</li>
</ul>
Adjusts coolant flow to maintain the ideal engine temperature.
<ul>
<li>Temperature regulation</li>
</ul>
Continuously adjusts to prevent overheating and ensure efficient operation.
<h2>Signs of a bad thermostat</h2>
<ol>
<li>Overheating: The engine becomes excessively hot due to a stuck-closed thermostat.</li>
<li>Low or fluctuating temperature: A thermostat stuck open results in a cooler engine, affecting fuel efficiency and heating.</li>
<li>Temperature warning light: Illuminates to indicate engine overheating due to a faulty thermostat.</li>
<li>Poor fuel efficiency: Stuck-open thermostat reduces fuel efficiency as the engine operates less efficiently at lower temperatures.</li>
<li>Inadequate cabin heating: Insufficient cabin heating in cold weather with a thermostat that's stuck open.</li>
<li>Coolant leaks: Gasket or sealing issues can lead to coolant leaks.</li>
<li>Rapid temperature fluctuations: The gauge shows rapid swings between hot and cold.</li>
<li>Engine running hot at idle: Higher engine temperature during idle or in traffic due to restricted coolant flow.</li>
<li>Slow or inconsistent warm-up: Longer-than-normal warm-up times, even in moderate weather.</li>
<li>Inconsistent heater operation: This affects the performance of the vehicle's heater, causing inconsistent or inadequate heating in cold weather.</li>
</ol>

Thermostat

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Air Intake Hose

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Air Intake Manifold Runner Control Sensor

Electric Vacuum Pump

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Engine Air Filter

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Intake Manifold

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Oxygen Sensor

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Air Filters & Intake Systems

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Harmonic Balancer

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Timing Belt Kit

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Timing Chain Kit

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Timing Cover

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Timing-Control Valve Solenoid

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Valve Lifters Tappet

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Belt Tensioner

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Crankshaft Position Sensor

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Engine Oil Dipstick Tube

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Oil Filter

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Oil Pan

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Camshaft Position Sensor

Camshaft Position Sensor & Magnet Kit

Connector Plug

Distributor Cap

Engine Valve Covers & Ignition Coils Kits

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Spark Plug

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Spark Plug Wire

Electronic Control Modules, Ignition & Distributors

Engine Wiring Harness

Intake Manifold Repair Kit

Engine Components & Accessories

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Auxiliary Water Pump

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Expansion Tank

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Expansion Tank Mounting Plate

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Fuel Cooler

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Radiator

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Radiator Support Assembly

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Temperature Sensor

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Turbo Hose

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Water Coolant Pipe

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Water Outlet

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Engine Cooling

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Engine Mount

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Engine Mounts

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Catalytic Converter

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EGR Valve

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Exhaust Fluid Heater

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Exhaust Gas Temperature Sensor

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Exhaust Manifold

Fuel Tank Breather Valve

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Fuel Vapor Leak Detection Pump

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Nitrogen Oxide Sensor

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Secondary Air Injection Check Valve

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Vapor Canister Vent Solenoid

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Exhaust & Emission Systems

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Fuel Filter

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Fuel Injection Pressure Regulator

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Fuel Injector

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Fuel Line Kit

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Fuel Pump

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Fuel Sending Unit

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Fuel Tank Filler Neck Pipe

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High Pressure Fuel Pump

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Idle Air Control Valve

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Oil Pressure Relief Valve

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Fuel Systems & Components

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The engine comprises many essential elements such as the lower cylinder block, upper cylinder head(s), and the cooling & lubricating systems. With A-Premium aftermarket engine components, you can expect that your engine deliver years of reliable performance. We offer a diverse selection of engine components from air filters and ignition coils (kits) to fuel pumps to cater to your needs.

2003 BMW 325i Thermostat

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