7 Logic Why Are German Cars Unreliable

German Cars Quality

After about four or five years, German cars started developing significant issues, coolant leaks, oil leaks, water ingress that would rot the chassis, timing, chain problems, and air suspension settling out in the car. It would collapse or fall onto one side, creating dangerous driving conditions.

Everybody knows BMW is known for its high-quality finishing performance, driving dynamics, overall quality feel, and stylish looks. Mercedes-Benz has a reliability issue, and the issue is generally new technology. Often, they struggle with reliability because they’re trying to introduce new technology and innovations.

Why are German cars unreliable?

Repairpal is an excellent resource because it brings all the data from across the nation into one common place that summarizes some key issues. It gives you an average cost per year of ownership and overall ranking. Does it rank is it above average reliability? Is it average? Is it below average?

Let’s talk about some generic models looking at over 300 unique, different models for repair ranks, and a Mercedes Benz is three out of five, which gives it average reliability. Also, it ranks 27th out of 32 manufacturers for overall reliability, which seems to be further down the list.

The average repair cost for a Benz is about $1,000 a year. Some will be a lot more, and some will be significantly less. With that said, the average across the industry is about $650. So this puts it slightly more expensive to own and operate than the average. That said, Mercedes Benz is not the average car either, and you have to pay to play.

Now, I will explain 7 reasons why German cars are so unreliable. Let’s go!

1. Electronics

Electronics help with the complexities. BMW’s state of the art always breaks through new trends, designs, and technology. But when they do that, there’s always a risk of things not being worked out properly. They’re trying new things that maybe haven’t been tried and true.

We’ve got power windows and mirrors and all different safety technologies. That adds a whole gamut of complexity to the car because it adds complexity. So, there’s always a risk of things going wrong.

2. Wiring

Another reason why BMW/Mercedes electronic and electrical systems sometimes act up or become slightly less reliable is the way it’s been installed. Some of the wirings have been routed in ways that create pinch points. Another classic one known to cause fires and have led to issues is drain plugs and poorly located drain plugs that allow water to dissipate away from collection points.

The water sits there, sloshes around, and sometimes contaminates wiring and wiring connectors, ultimately deteriorating connections. Also, the wiring itself outright failed of whatever circuit it fed. So that’s another reason you want some great examples of failures.

3. Electrical issues

Signals are another one that people associate with German cars. There are also ones that become more than an inconvenience where a door lock isn’t working or a power mirror isn’t working. How about ones that create safety hazards? An internal heater in this PCB would short out and cause an engine fire.

The whole cargo is black, which can happen at very hazardous speeds. There have been cases noted where people veered off the road and got either severely injured or killed due to total loss of visibility, lights and power, and everything in the car. So German cars have many examples of safety issues in the electrical system, making them unreliable.

4. Use of plastic

The central failure point or why people would consider some German cars unreliable is the extensive use of plastic. Plastic parts are not new to the BMW world. Everybody knows that it’s no secret that BMW uses plastic and a lot of things.

For example, cooling systems, water pumps, and radiators are all made of plastic that deteriorates quickly. That leads to leaks, possibly misfiring.

Turbocharged is fantastic for performance, not for reliability, because a lot of plastic was used there. The turbocharged pipe or the boost pipe is not very strong. If you applied any more boost than you would expect from the factory, they often split, and they would leak boost. So you find yourself in a situation of leaking boost and reduced power.

5. Throttle actuator

The throttle actuator is a great little device, but it’s not great on the inside, where there exist tiny plastic gears that rotate and strip out. When they strip out, you get a code, the engine goes into limp mode, and you can no longer enjoy the spirited fun the car intended to provide. If you have ever removed door panels, you want to run some wire. Behind a panel, BMW uses these wonderful little plastic fasteners.

They often break off, the head falls apart, or they get too sloppy. So they can’t push and retain the original piece. As a result, a lot of times, those fasteners fall apart.

6. Valve guide seal

The V8 motor engine uses a particular style of valve guide seal that is not fitted for its application. As a result, the valve guide seal leaks oil and creates a scenario where the car burns a lot of oil.

So it’s a mismatch of either material, the parts, the sizing, the specification, whatever it’s a material concern. They put the rubberized O-ring to seal around the guide and the valves.

7. Heavy engineering

One of the primary reasons the German car is unreliable is its heavy engineering design. But they’re a bit light on research and development. The N47 turbo diesel engine was notoriously bad in breaking or taming timing chains coming loose and engines catastrophically failing.

The S85 is so great, and the whole design of tolerances was way too tight. The oil specification was too heavy, and a combination of the overall design was not conducive to the long life of the rod bearings.

Weakness, research, and development did not flush out the fact that tolerances were too tight, the oil was too heavy, and overall it was a poor engineering exercise that evolved into this wonderfully exciting engine to drive but highly unreliable.

Know more about cars:

Why Are Japanese Cars So Reliable?

Why Are German Cars Expensive?

Why Are German Cars So Popular?

Why Are G Wagons So Costly?

Why Is Toyota So Popular?


“Volkswagen Group Volkswagen and Porsche finalize creation of Integrated Automotive Group” (Press release). Volkswagen Group.
Facts about Germany. “Car-making: The strongest sector.”

Julia Rose

My name is Julia Rose. I'm a registered clinical therapist, researcher, and coach. I'm the author of this blog. There are also two authors: Dr. Monica Ciagne, a registered psychologist and motivational coach, and Douglas Jones, a university lecturer & science researcher. I would love to hear your opinion, question, suggestions, please let me know. We will try to help you.

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