Changing Filters on the W245 B-Class 180CDI

W245 180CDI Engine

There are quite a lot of filters on this car. Diesel fuel filter, air filter, oil filter and pollen filter. I will cover all of them but the oil filter in this article (the oil filter will be addressed in a separate oil change guide). You can buy complete filter kits which include all filters. I recommend doing that to save some hard earned rupies and then changing all of them in one go, they probably are all overdue anyway.

Pollen Filter

Having that dampness and weird smell in the cabin gain? It’s not always a fart. Changing the pollen filter might address the issue. It’s also the most overlooked filter on the car. Many people does not even know it exists. Especially if you have been around older cars which do not have them! There you have the good old fashioned unfiltered atmosphere straight into the cabin.

So where do you find the pollen filter? Start by opening the hood. At the plastic cover above the engine is a narrow plastic lid. Open it and there you will find the filter.

Pollen filter location W245
Say hello to pollen filter

The pollen filter is a flimsy piece of paper which you can easily swap without any tools. Mess this up and you are a clown.

Old vs new pollen filter
Can you spot the old filter?

Well done you completed 1/3.

Air Filter

Time to step it up a notch. Now you will require some actual tools. Some torx bits to be specific. The air filter is located at the top of the engine and you can’t miss it. You have to loosen the plastic cover which is held in place by torx screws all around it. Be careful not to loose the screws into the engine bay and you will never find them again.

Air filter løocation w245
Location of air filter box

You don’t have to loosen the air intake tube going to the turbo. And if you do, it’s important to get the seal completely tight again. Not so easy.

Can you spot the new filter?

Now you have done 2/3, well done. Maybe you’re not a clown after all? Lets step over to the diesel filter.

Diesel Filter

The final and hardest part. Here you will utilize at least a screwdriver. You should also consider getting new hose clamps if the old ones are rotten. In older mechanical diesels injection systems it was a pain to change the filter, since you had to manually pump and bleed the injection system for air after changing filters. Now the car will do this for you with the electronic injection system. To be honest I did zero pre-studying before doing this job and wasn’t 100% sure if this would happen, but it was no issue starting the car afterwards. So no worries!

Locate the diesel filter on the right side of the engine. It should be easy to spot. It’s a canister with two hoses going into it. Note the location of each hose, take a picture so you don’t cross them when installing the new filter.

Diesel filter Mercedes W245
Location of diesel filter.

Unscrew the hoses and beware of diesel pouring out, prepare some paper to catch the spilling diesel. You should be extra careful of spilled diesel here since the exhaust is just beneath. This can catch fire if a lot of diesel is spilled, and I don’t want you to blame me for you burning up your own car.

The filter canister is clamped tight by a couple of spring clamps which you can loosen by hand.

Filter canister secured by two clips.

After installing the new diesel filter. Start the car and inspect closely for diesel leaks. Tighten the clamps if you see seepage. Alternatively the hoses might need replacing if they have started to seep from cracks. Diesel leaks here might cause engine fire and you have now been warned!

If you managed to complete this 3/3 step, you are already at novice DIY level and congratulations! Who said fixing your car was difficult? Hardly need any tools at all.

Robs out!

Author: Robs

Passionate about vintage Mercedes Benz where driving, maintaining and learning new things and teaching others on the black arts of car maintenance.

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