Symptoms of a Failing Thermostat in a Volkswagen
The thermostat in your Volkswagen regulates engine temperature and is an essential component of your vehicle’s cooling system. It controls the flow of coolant between the radiator and the engine. When the engine is cold, the thermostat shuts to enable it to heat up, and it gradually opens as the engine warms up, allowing fluid to reach the radiator. It’s a simple part which performs an extremely important duty. However, it is also susceptible to wear and tear since it is in constant use every time your engine is on.
When your VW’s engine thermostat malfunctions, you’ll encounter different kinds of issues with your car. A burst head gasket, a spiking temperature gauge, and other signs of a malfunctioning thermostat are typically easy to recognise.
Your car will alert you to the fact that your thermostat is malfunctioning in one of several ways, either by the check engine light or by one of the following symptoms:
A Blown Head Gasket
The head gasket can blow/crack if you drive your car for a long distance while there is no coolant flowing through it. Rough idling, water in the oil, poor fuel mileage, and plenty of white smoke from the exhaust are all signs of a blown head gasket.
Unfortunately, the process of replacing a head gasket is time-consuming for mechanics and is, therefore, expensive. Hopefully, you will discover your malfunctioning thermostat before this malady occurs.
The Engine is Too Cold
Your car’s thermostat is likely stuck open if it doesn’t generate heat. Coolant is constantly cycling through the engine when it is on and things are running as designed. When the valve is stuck open, the coolant runs through without varying and your engine will run too cold to function properly.
Overheating of the Engine
One of the most common indications of a malfunctioning thermostat is when the engine overheats. The thermostat is most likely stuck in the closed position, and the coolant is prevented from entering the engine as a result of this. When this happens, the coolant cannot circulate throughout the engine’s hottest parts. This will be a rapid response after you turn on the engine.
Causes of an Engine Warning Light or Temperature Gauge Spike
Most VW owners will notice an engine warning light or a raised temperature gauge as the first indicator of a failing thermostat. If you observe this, pull off somewhere safe and turn off your car engine as quickly as possible to avoid any further harm to your engine’s parts.
The warning lights might come on due to the malfunctioning thermostat. However, other factors that can make the temperature gauge increase include:
- Low Coolant: If you’ve been losing coolant in your car, you may have finally spilled out enough that the cooling system can’t keep up.
- Bad Radiator: Your car will overheat if the radiator has become clogged to the point where coolant cannot efficiently move through it.
- Water Pump: The water pump is in charge of moving coolant via the radiator to the engine. Even if the thermostat is open, water will not circulate through the car’s cooling system when it goes bad.
- Coolant Leak: You’ll notice coolant leaking around the thermostat casing as pressure develops around a defective thermostat that is stuck shut. This leak is a sign of a faulty thermostat in your car, not the cause.
Replacing a Failed Thermostat in a Volkswagen
A thermostat replacement is a relatively inexpensive repair. If you ignore this problem, it will undoubtedly cost you more in engine repair 
than it would to replace the thermostat. It is best to find a VW specialist who knows your model and who will inspect your car properly to ensure they find the root cause. Munich West is happy to perform this inspection and repair for you at a fraction of dealership cost.
Munich West is Atlanta’s leading European auto service center in your area! Our skilled technicians at Munich West provide extensive service and repairs for the most popular European brands, including Volkswagen vehicles.
We are located in Decatur, Georgia, and we gladly serve automobiles from the Atlanta, Avondale Estates, Buckhead, Lilburn, Stone Mountain, and Tucker areas. We look forward to helping you get your Volkswagen fixed. To find out more about our services, call us now!
