As you may have heard, MAHLE intends to sell the thermostat division to the company Admetos. What does this mean for you as a MAHLE customer? Nothing - you'll still be able to exclusively obtain MAHLE thermostats through our global network.
In our new series introducing products, we want to give you the essential information from the experts about different vehicle technologies in a compact, simple form. Today, we’re starting by examining the thermostat in detail. This is an area where MAHLE Aftermarket offers not only a broad product portfolio but also extensive experience in all the leading thermal management technologies. Whether you’re looking for passenger car or commercial vehicle options, MAHLE supplies thermostats, thermal switches, and thermocouples for all kinds of applications.
How do engines and auxiliary components reach operating temperature quickly, yet stay cool when they have to work hard? What temperature range is the most energy-efficient and low-wear for the engine? Thermostats are responsible for regulating heat.
Smart control of the coolant flows ensures that the optimal temperature is reached more quickly and held constant.
The heart of the coolant thermostat is the thermal expansion element. As the temperature changes, this wax element changes volume and acts as a regulator through the stroke movement of the piston. When the engine is cold, the coolant circuit remains closed, and the engine components warm up more quickly. Instead of flowing through the radiator, the coolant passes through a smaller circuit known as the by-pass loop.
Heat from the engine warms the coolant up to a defined temperature. Just before the optimum temperature level is reached, the thermostat opens the flow inlet to the radiator, and the coolant is fed through the radiator to prevent the engine overheating. If the temperature rises too sharply, all the coolant circulates through the radiator while the by-pass loop closes, again avoiding overheating of the engine. The cooling circuit of the auxiliary components can also be controlled separately following the same principle used by the engine’s primary cooling circuit.
In our thermostat brochure, you can take a detailed look at everything related to the component:
But that’s not all: thanks to modern electronics, thermostats are also able to improve efficiency and consumption values. But how does map-controlled thermostat technology actually work? How do we safely raise the operating temperature of passenger car engines to a constant higher level, thus optimizing combustion and all accompanying parameters?
The vehicle’s control unit electronically activates an integrated heating element on demand, shortening control times compared with conventional wax elements. As a result, the map-controlled thermostat controls the engine temperature more quickly and more precisely in different load and operating conditions, always keeping it in the optimal range.
The operating map is a dataset in the engine control unit. Depending on the operating conditions, it provides optimal values for the temperature and mode of the cooling circuits. In addition, the electronic control unit analyzes the current output profile to determine, for instance, whether the driver is calling on the engine to perform at a high or low level. Load-dependent regulation of the temperature level allows for optimal engine temperatures, enhanced efficiency, and fuel savings of up to 2 percent.
Depending on the application and size of the unit to be cooled, other thermostat variants include integral thermostats, housing thermostats, and sleeve valve thermostats. EGR thermostats and oil thermostats are also used to regulate exhaust gases and oil temperature, respectively.
Small errors when installing a temperature regulator can have serious repercussions for the cooling circuit and the engine.
To prevent mistakes and make sure you’re fitting thermostats correctly, why not top up your knowledge using our installation poster or Technical Messenger, our regular information leaflet?
As a workshop professional, you can benefit from a comprehensive range of information, advice, and services relating to thermal management control units. Our technical posters and newsletters, catalogs in digital form, plus animations give you practical, expert support that’s always tailored to your needs. On top of that, we also offer regular theoretical and practical training. Find all the content at www.mahle-aftermarket. com under 'Services'.
To provide you with a deeper understanding of thermal management components, we've developed the MAHLE TechTool. At techtool.mahle.com, you'll find firsthand knowledge about thermal management. The tool offers free insights into technical processes, assists in active troubleshooting, and explains how vehicle air conditioning and engine cooling work under the hood. Content specifically about thermostats includes:
Sleeve valve thermostat and thermostat insert
Map-controlled thermostat, housing thermostat & thermostat insert.