The Mercedes-Benz W205 C200 model features the most widely used engine spec from this period, the 2.0 gasoline M274 engine. This model was produced during the initial years of its release.
Since it’s an early model, it has a 7-speed transmission instead of a 9-speed.
It had accumulated 180,000 kilometers at the time of arrival. The owner came in to replace all fluids, including engine oil, transmission oil, differential oil, and the air conditioning filter!
However, there’s a problem...
Warning lights have appeared.
The owner didn’t provide any specific explanations, so I started with a scanner diagnosis.
Wow... all the warning lights for the C200 M274 engine are on. The issues include problems with the coolant temperature thermostat, a blockage in the crankshaft exhaust valve actuator, and a broken oil pump solenoid valve.
Here’s a quick look at the Mercedes triple warning lights.
Usually, when one warning light comes on, we handle it right away, so it's rare to see all of these together. It makes me think that either the owner ignored the warnings or they just happened to all show up at once.
Fixing everything would be ideal, but with 180,000 kilometers on this C200, the repair costs could be significant.
After consulting with the owner, we prioritized clearing the warning lights on the dashboard. We decided to start with the thermostat and crankshaft exhaust valve, and we'll address the oil pump solenoid valve later.
* The oil pump solenoid valve usually doesn’t trigger a warning light. It appears on the scanner, but who knows how Mercedes has set it up... it rarely shows up. Occasionally, some vehicles do have it light up, though.
Due to the warning lights, my plan to change all the oils at once fell through. For now, we’ll only change the engine oil, filters, and differential oil, and we’ll handle the rest once the parts arrive.
When I opened the oil cap to change the engine oil, I was surprised to see so many foreign substances... it’s quite noticeable.
We usually don’t recommend flushing, but...
We’ll proceed with the flushing.
While the flushing oil circulates, I’ll replace the air conditioning filter. How does it look? The condition is as shown in the photo.
Mercedes models from this era have air conditioning filters that can be quite expensive to replace. This might explain why many owners tend to neglect them.
On average, this is how dirty they get.
The photos turned out really clean, probably because I used a mirrorless camera.
I’ve uploaded a few photos on Instagram, but all imported cars, including this one, really need air conditioning filter maintenance.
Compared to domestic cars, the filter prices are higher, and the replacement method isn’t easy, so many people don’t do it themselves.
When you turn on the air conditioning or heater in a cramped car interior, you’re breathing in the air that comes through this filter... so it’s definitely worth replacing, right?!
For those reading this and thinking, “Wait?! When did I last do this?!”... if that’s the case, it’s probably been over a year.
Regardless of the type of car, I recommend changing the air conditioning filter every year!
Change it before you turn on the air conditioning or heater.
Just like you clean and dust your home air conditioning unit, you should pay attention to your car too!
I think I’ll also need to check the belts soon. I didn’t take a photo, but the flexible joint has a crack.
Remember to come back for your next service!
I added a bottle of washer fluid.
I drain the oil once the flushing oil has circulated adequately.
Fortunately, the oil color improved, and a lot of foreign substances came out.
I replaced the air cleaner (the air filter needed for the engine).
I also changed the oil filter.
I also changed the differential oil!
* Since it’s a 4MATIC with 2-wheel drive, I only needed to change the rear differential.
If it were 4-wheel drive, I would also need to manage the front differential and transfer case oil.
I added new engine oil.
I checked the oil level and adjusted it, then moved the car to the parking lot for the next task.
The posting continues!
What’s next?! I’ll be working on the transmission oil and the thermostat, crankshaft exhaust valve... to be continued!