If your Mercedes is hesitating to start, there are three main components that may be the source of the problem: the electrical system, the starter, and the fuel system. These components are all integral to the functioning of your vehicle’s engine and, therefore, deserve regular maintenance and care.

Electrical System Issues

One of the most common causes of engine hesitation while starting is issues with the electrical system, more specifically, the battery and the alternator. When you turn the key in your vehicle’s ignition, the battery is supposed to provide a jolt of energy that allows the engine and its support systems to start running. However, if your Mercedes’ battery is more than 7 years old or is poorly charged, then it may need several tries to produce this jolt, thus impairing the engine starting process. So, if your vehicle’s engine is slow to start, you should first examine the battery to make sure it is relatively new and properly charged.

If the battery seems to be in good condition but is still unable to produce enough electricity to start your vehicle, then the problem may instead lie with the alternator. The alternator’s purpose is to recharge the battery while your vehicle is in motion, and if it is broken, then your battery will struggle to hold a charge. This can lead to engine starting troubles as described above.

Starter Issues

If your Mercedes is slow to start but its battery and alternator appear to be fine, then the next component to check is the starter. There are two possible starter issues that might interfere with your vehicle’s ability to start.

First, the starter itself might be defective. If this is the case, the engine will struggle to turn over, thus making it difficult to start. Alternatively, the starter’s fuse might have blown out. If this is the issue, then the starter will again struggle to make the engine turn over and will slow the starting process.

If either of these problems occurs, then you should take your vehicle to a professional mechanic to have the situation solved as soon as possible.

Fuel System Issues

A third component that facilitates your Mercedes ability to start is the fuel system. If your vehicle’s engine is not receiving the right combination of oxygen, fuel, and pressure, then it will struggle to start, and may eventually fail to start at all. Fortunately, it is possible and relatively easy to measure your Mercedes fuel system pressure levels at home. You will need a fuel pressure gauge with a Schrader valve adapter, which can be purchased at most auto repair stores.

In order to conduct the test, turn your vehicle’s engine off and connect the gauge to the Schrader valve test port beneath your vehicle’s hood. Then, turn the engine on. This should produce a reading of approximately 60 psi. Now, shut it back off. If the pressure reading fluctuates between when the engine is on and when it is turned off, then your Mercedes fuel system likely lacks adequate pressure levels, making it difficult for the engine to function properly.

If your vehicle’s fuel system exhibits steady pressure levels but your engine is still struggling to start, then you should examine the fuel pump and the fuel filter, as damage to either of these parts can make it difficult for your vehicle to start. Fuel filter clogs can be particularly problematic, as they can prevent fuel from reaching the engine. These should be dealt with right away if discovered.

We Will Help

Finding out why your Mercedes is hesitating to start might be easy, but solving the problem is often significantly harder. Therefore, if you’re having trouble starting your Mercedes, you should take your vehicle to a professional technician as soon as possible.

At Woodinville Sports Cars, our certified mechanics have the tools and experience necessary to fix all manner of engine-related problems. For years, we have proudly provided quality service to drivers in Bothell, Kenmore, Kirkland, Mill Creek, Monroe, Redmond, Snohomish, and Woodinville, WA. We would love to help you keep your Mercedes in the best condition possible, so give us a call or stop by the shop today.