Mercedes-Benz models are elegant, powerful, and have a reputation for excellence. They can sometimes face serious mechanical issues. An especially-common problem in Mercedes is thermostat failure. Accordingly, Mercedes owners should be able to identify both the common causes and the common symptoms of thermostat problems so that they can keep their vehicles running smoothly.

Understanding the Thermostat’s Purpose

The thermostat is an integral part of your Mercedes cooling system. In essence, it is a valve located between the engine and the top radiator hose that opens and closes to control coolant flow.

When you first start your vehicle, the thermostat stays closed, allowing the engine to quickly reach the correct operating temperature. Once the engine reaches this temperature, the valve opens, letting coolant flow into the engine and preventing the system from overheating.

Common Causes of Thermostat Failure

Several factors can cause your vehicle’s thermostat to malfunction, the most common of which is normal wear and tear. The thermostat is routinely exposed to chemicals and extreme temperatures. So over time, it will naturally begin to wear out. When this happens, the temperature at which the thermostat opens slowly rises until the thermostat remains shut, even when the engine is overheating. Needless to say, this can cause serious damage to your vehicle’s engine.

Two additional causes of thermostat failure include overheating and sludge build-up. Your Mercedes thermostat uses sensors to determine when it should open and close, but if the engine overheats, those sensors may be overloaded. If your vehicle’s engine has overheated in the past, your thermostat may be broken.

Also, coolant can sometimes congeal into a thick sludge, especially if it becomes contaminated. When this happens, the sludge can gunk up the thermostat and stick it in either the open or closed position. All in all, problems with other parts of your vehicle can cause considerable damage to its thermostat, so you should be sure to perform regular maintenance on your Mercedes.

Another common reason of thermostat problems is human error. Mercedes manufacturers and mechanics are known for the quality of their work, but there is a slight chance that someone may have mishandled your vehicle’s thermostat during assembly or routine maintenance. For example, the shop that produced your Mercedes may have overlooked a small defect in its thermostat, or an inexperienced mechanic at a domestic shop may have replaced the thermostat incorrectly. Regardless of the specifics of the problem, human errors can sometimes have severe consequences for your vehicle if not corrected for.

How to Tell if Your Vehicle’s Thermostat is Broken

There are two potential ways that your Mercedes thermostat can fail: it can either become stuck in an open position or stuck in a closed position. Although neither of these situations is ideal, the first is somewhat less problematic than the second.

If your Mercedes thermostat becomes stuck in the open position, coolant will flow constantly through the vehicle’s engine. This will cause more problems later down the line, as it will negatively affect your vehicle’s performance, but it will not have any immediate negative consequences. The best way to tell if your thermostat is stuck open is by checking the engine to see if coolant begins flowing immediately after the vehicle is started. Watching the temperature gauge on the dashboard for any unusual fluctuations can also be helpful.

In contrast to a situation where the thermostat is stuck open, an instance where the thermostat is stuck closed can have immediate consequences. Namely, a closed thermostat can cause your vehicle’s engine to overheat and its thermostat housing to spring a leak.

If you notice either of these symptoms, you should have a professional check your vehicle’s thermostat right away, as failure to take care of the problem could cause your Mercedes engine to fail entirely.

Experts to Replace your Vehicle’s Thermostat

Replacing a Mercedes thermostat is a challenging task that should only be entrusted to an experienced technician. Our mechanics at Das European Autohaus are the premier choice for Mercedes repairs in Spring and Houston, TX.

We are committed to quality care and friendly service, and we have the tools and knowledge necessary to help you keep your European vehicle in top condition. So give us a call today to learn about the “Das” Difference and what it can do for the longevity of your Mercedes.