Engine oil and filter change on the B-Class 180CDI W245

This is the most modern car which I have written an oil change procedure about. What is the difference here compared to the older cars? To be honest not much! The only difference is the car computer needs to be told that an oil change has happened and the service interval be reset through an OBD2 diagnostics unit. The OBD2 diagnostics unit can be found quite cheap online, but make sure you get one that works for this model with the capability to reset service intervals and fault codes. Since the more basic ones can only read fault codes.

Preparation

Get the necessary parts and oil. Here you need a filter kit, which contains the oil filter element, two rubber gaskets for the filter housing and a new drain plug with a new copper washer. Make sure to not get the cheapest filter you can find, since in my experience the filter element can start to deteriorate if you have long service intervals. This car is rated at 15.000km between oil changes, but I suggest doing them at 10.000km.

Parts:

  • Oil filter kit
  • Oil: Keep at least 6L on hand- The car needs around 5,4-5,8L

Tools:

  • Jack and jack stands
  • Sockets
  • Oil drain pan

I tend to use Castrol’s oil picker to find which oil I need for any car, but if you prefer other brands then I have no objection. Anyway Castrol recommends Edge 0W-30, but this could change if you plan to use the car in more extreme weather conditions. Refer to the owners manual if in doubt.

New engine oil for 180CDI
0W-30 Oil for 180CDI

Procedure

The engine should be at operating temperature to make the draining more effective. So prepare the oil change after a trip, either back from work or after the store.

I’m always a bit shocked when checking the oil on diesels since it’s usually pure black in color after a relatively short time. This car had some time since the last oil change and the level was quite low. This did worry me a bit since the car is at 250.000km already. It is always a good idea to check the bottom of the oil drip pan for sludge and metal shavings to assess the condition of the engine every time when changing the oil. So with that in mind, hoist up the front of the car on jack stands. This car has a very low ground clearance and it’s impossible to access anything under there.

Start with locating the oil filter element in the engine bay. It is on the right side of the car just behind the turbo. It is a bit cumbersome to reach with a socket, but you don’t need any special filter tool to remove it. The access will be much easier if you have a socket with a joint as shown in the picture below. Take out the old oil filter and then move to beneath the car.

Oil filter 180cdi
Oil filter location. Use a socket with a joint to get better access behind the turbo

If you haven’t seen under this car, everything is hidden beneath plastic panels. You have to take at least 2 of the panels off to get access to the oil drain plug. The oil drain plug is also a joker to find, since it’s not where you expect it to be traditionally. It’s at the very rear of the engine far behind the front wheels. It is the most left plug on the engine block (see image).

Oil drain plug location B180CDI
Oil drain plug location on the 180CDI. You need to remove some plastic panels to find it.

I’m not sure what the plastic panels are for except aesthetics and hiding the under body. Also it can trap moisture and rust. They have some very subtle sound dampening effects and can keep some of the dirt away. Maybe it decreases air drag at high speeds? But I didn’t bother to put them back on. They were quite cracked and had a large hole due to the low ground clearance. I prefer seeing whats going underneath the car and the ability to wash off the salt underneath there especially in the winter.

Now that the drain plug is located. Start drain the oil and try not to loose the plug into the pan when opening it. The oil should drain a while until the dripping stops. Then take the new drain plug with the new copper washer and use that to plug the drain. Do not overtighten! Maximum 30Nm.

Draining oil from 180CDI
Draining oil from the 180CDI

After the drain plug is secured. Then it’s time to change the oil filter. The oil filter cap contains two rubber seals, remember to change both of them! Use a rag to clean up inside the oil filter housing for old oil. Mount the new filter onto the oil filter cap and then reinsert the filter cap into the filter housing. Tighten the filter housing to max 25NM. Over tightening will ruin the plastic so be careful.

Oil filter kit parts B180CDI
Oil filter kit parts. Note the two rubber seals, along with new drain plug and washer. See the old filter how deteriorated it is, it’s almost falling apart. Indicating cheap filter and overdue service interval. The new filter is a honeycomb structure and not a cheap paper filter like the old one.

Recheck that you actually secured the oil drain plug under the engine before you start pouring in the new oil. The car needs 5,4L to 5,8L, but there is probably some residue and the actual amount might be a little less. Start by pouring 4,5L. Level the car in order to make a proper reading of the dip stick. Then pour little by little until max level on the dip stick is achieved.

Oil pan with old oil from diesel engine
Inspect oil from the oil pan. Since this is a diesel it’s completely black. This is normal for a diesel. Also use your smell, does it smell really burnt? This could indicate overdue interval. Also check for sludge at the bottom of the pan which can indicate old oil. Check for metal shavings which can indicate bearing wear and poorly maintained engine.

Check the oil drain pan for assessing the health of the engine and if the service interval have been overdue. Luckily there were no sludge or metal shavings from my oil, but it smelt strongly burnt. Which with the low oil level may indicate an overdue oil service interval. Thankfully I switched this oil in this before doing any driving at all after getting it. The engine is quite strong and starts easy without any smoking indicating a healthy engine still. Phew!

Now the last part is to tell the engine computer that an oil change have been done and reset the service interval. The annoying wrench and reminder every time you start the car will then go away. Unfortunately I didn’t take pictures of this process, but it’s really a straight forwards procedure.

  1. Connect the OBD2 to the connector underneath the steering wheel.
  2. Select the car and engine type with manufacturing year
  3. Go on the menu which you can reset oil service interval. These can be different depending on the type of reader, but should be pretty obvious
  4. Set that oil service have been done, this will remove warnings on the dashboard
  5. While you’re at it, do a scan of error codes if any

Now you can do an oil measurement while the key is inserted and the engine is off. You can access this through the interactive computer in the dashboard through the buttons on the steering wheel. The car will then tell you if the level is OK or not.

If everything is OK and no service interval warnings. It’s time to start the engine. While the engine is running. Inspect underneath and see that there are no oil leaks form the drain plug and also check the oil filter housing for leaks. If no leaks, go for a small 5min drive. When back, recheck the dip stick level when engine is off. Refill more oil if necessary. Also recheck for leaks underneath and at the oil filter housing.

Robs out!

Changing Filters on the W245 B-Class 180CDI

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!

Changing the windshield wiper mechanism front and rear on B-Class W245

The major issue with this car which basically prevents me from driving it is a malfunctioning front window wiper mechanism. It rains quite a lot here especially in the autumn, also it’s illegal to drive without them. While the front window wipers are essential, the rear one is not working either. Side view mirrors are often enough, however the mirrors on this car are so small and “well” designed so you can’t really see whats directly behind you. So I will need to fix that one as well.

The front wipers were almost not working when picking up the car when I bought it and the wipers were stuck in a weird position. Unfortunately it was heavy rain this day and not really possible to drive without it. When inspecting the mechanism it turned out that the motor was fine, but the wiper bracket was broken due to a totally seized right side wiper shaft.

After some 2 hours of fiddling in the rain we managed to get the driver side wiper to work (barely). The drive home was quite interesting where I operated the wiper only when strictly necessary. Thankfully it worked all the way home with no fuzz.

Front Wiper Mechanism

The access to the front wiper mechanism is easily made with removing the plastic cover just over the engine beneath the front window. But first open the hood to get better access to the wiper arms. Some care here is needed so you don’t crack the front windscreen, such as dropping your tools and slamming the spring loaded wipers on the window.

Removing the wiper arms can be a challenge if you don’t know the trick. Unscrew the nut half way, then use an open ended wrench to pry off the wiper arm and voila it’s off. Once both wiper arms are removed, you can remove the plastic guard cover. It’s only held in place with 6 hex screws located at the top of the engine bay. Take care not to loose any tools or screws into the engine bay. You will never find them again from the bottom of the engine bay.

The wiper mechanism itself is easy to take off. There is one cable to the motor, then the mechanism is held together with 3 bolts. When reinstalling a used one, or refreshing the existing one. It’s an excellent opportunity to lube the wiper shafts with some oil and put some grease on the mechanism joints. Much easier than when it’s on the car.

Before reinstalling the wiper mechanism, make sure the joints are installed the correct way. Use the article as reference since there are two ways the joints can attach to the middle pivot bar. Installing them the wrong way might ruin the assembly when turning on the key. Also beware that the motor is really powerful, so don’t put your hand or fingers down in the mechanism while someone is turning the key or checking the mechanism from inside the car. Ideally the battery should be disconnected while working on the wipers.

Before assembling the whole thing, make sure the wiper mechanism works properly by turning on the wiper motor and inspect that the mechanism works without any issues and clears all obstacles under the windshield. There is some wiggle room for the bracket in the 3 mounts. Then you can put back the plastic cover.

Working mechanism, quite fun to look at.

Installing the wiper arms is probably the most difficult with this job, since it needs some fiddling and adjusting to get the correct angle. The two arms are not equal either so make sure to put them on correct to their assigned side. When aligning them, you will need to try them out and see if they have enough clearance when operating while also cover most of the screen. This might take a couple of tries, so be patient. When they are aligned, then put back the plastic covers and your are done.

The issue with this type of wiper arm design is that the wiper arms seem constantly to fight for position. If one binds or get stuck the other wiper will most likely break the other arm with a punch! A problem in older cars with more non-synchronized wipers like these is that they end up fighting for the windscreen and the wiper arms get bent, for example Lamborghini Espada.

Car is now capable to handle rain again!

Feels good to have working wipers again!

Rear wiper mechanism

The rear wiper motor is easier to replace. First remove the wiper arm, or if it’s broken off like mine, remove the nut. Then open the rear hatch, there is a plastic cover under there which can be removed without tools. Just use a plastic prying tool to snap it open.

The wiper motor has a plastic tube which needs to be unhooked. The plastic tube delivers wiper washer fluid to the rear window. Don’t worry, it will not leak water when unhooking it. Don’t mess up the plastic spring, otherwise you will leak washer fluid into the boot. Also unhook the power plug.

Plastic retainer to secure the washer fluid tube.

The window motor is held in place by only three bolts, and when removing these you can slide out the whole motor from the rear.

A new rear wiper blade comes actually wih a new arm as well, since the wiper blade is quite special and non-standard. It is not super cheap, buit not expensive wither. Installation is just reverse of disassembly, remember to test it and check for leaks before finishing at the end.

Working rear window wiper mechanism. Nice when spying on the cars behind you, not that there will be any cars behind this super fast 180CDI!!!!

My experience so far with working on this car is that it’s actually super easy to work on. It seems that if a car is easy to assemble on the factory thus making it cheap, it will also be easy for the home DIY mechanic to do work on. I’m quite happy for that. Older cars are usually more complex in their build and also a bit harder to work on.

Robs out!

How to change Engine Oil and Filter in the M120 Engine – W140 S600

The W140 How To.. articles are too and far between, especially on this site. Gladly on my part (sadly for you guys…) there has been very little wrong with this car and there’s not much maintenance either since the S600 has not been used as a daily driver. The W140 appears to me as a very over engineered car with an extremely durable design. As mentioned in the review, it is quite heavy due to all the extra sound dampening and extra equipment for comfort. I have never been in such a quiet car ever. Rolls Royce is probably the only comparable here. But as any other car, it too require regular maintenance such as oil changes. So how do you change the oil and filter for the engine in the M120 V12 engine. Sounds a bit scary right?

Preparation

This Mercedes model was one of the last one without the common OBD2 interface, and it is not required to a use any electronic diagnostics tool to reset some car computer during the oil change. What you need though is a lot of oil, A lot with a big A, 11 Liters to be exact. Remember to get an oil filter too, please get a good German known brand since they will last longer, not disintegrate and not ruin your engine. The price is anyway insignificant at this point. You don’t want to cheap out here, trust me.

Another tip is to get 2 new air filter elements since you will be messing with the air filter box anyway. And since they are cheap and should be replaced regularly it is a good time to change them now.

What type of oil then? Well it kinda depends on the conditions used, warm climate vs cold, harsh driving vs. balanced etc. I am using the car mainly in summer in a moderately tempered climate and use the car quite balanced. So no need for high performance or very cold weather conditions. However the engine is quite large and is quite slow to get up to operating temperature, so a thin cold start oil is probably beneficial to avoid unnecessary wear and tear when the engine is running cold the first 5 minutes.

I ended up using Castrol’s recommendation chart and it recommended the 0w-40 Edge fully synthetic oil. This is not an ad for them, but easily available here.

You will also need a special oil filter cap tool which can be acquired quite cheap from any car parts supplier. The cap is tightened to 25Nm and is nearly impossible to remove by hand. It’s also made of plastic so it can break, a new cap is not cheap. The trick here is however to get the correct one since there are hundreds of different ones. I spent quite some time to figure out the correct one without actually looking in the car and measuring. Firstly I couldn’t travel physically back then due to the lock-down and secondly I didn’t want to fiddle with the car just to find out the specs for the tool. (The oil filter cap is not visible by just opening the hood and requires removal of the air intake box). The oil filter removal tool is 74mm width with 14 slots.

Parts and tools

  • Oil filter (oil filter comes with new oil filter cap o-ring and a copper washer for the oil drain plug)
  • 11L of Oil, your choice, e.g. 0w-40 fully synchetic
  • Oil filter cap removal tool. 74mm 14 slots

Procedure

The oil removal process can be done with a oil suction pump inserted from the top of the dipstick tube and then removing the drain pan plug after, this makes less of a mess and is done in most workshops. However then you need an extra tool, so this guide will only use the drain plug method.

The engine should have normal operating temperature while changing the oil, since the oil will drain out easier, so take the car out for a drive before or plan to do the oil change straight after a trip.

S600 Oil dipstick before oil change
Oil dip stick before oil change. The car has run about 15.000km since last oil change and the oil is still very clear in color with a slight hint of brown. The engine has received zero refilling of oil during this time and is still showing max capacity. I’m very impressed.

Start by lifting the car up in the front and place it on jack stands in order to access the oil drain plug. Some of the w140 have plastic panels hiding the drain plug, so make sure to remove these. However my car does not have them and the drain plug is easily accessible. Before draining the oil from below, the oil filter must come out to allow better drainage. After opening the hood it can be very confusing locating the engine oil filter housing, and in fact you cannot see it unless you remove the left side air filter box. It’s well hidden below it.

Location of engine a oil filter housing on the M120
Location of engine a oil filter housing on the M120. Hidden below the left side air filter housing

Thankfully it is easy removing the air filter housing. It’s attached by two bolts and a couple of clips to the intake housing. You also need to disconnect one airflow sensor cable. Take care not to loose the intake hose clips into the engine bay which can be hard to recover, since they can come loose by themselves after loosening the air box. Loosing such a clip will make dirty air potentially enter the engine since it can then bypass the air filter.

Removing engine oil filter cap
Removing the engine oil filter cap. Almost impossible to unscrew by hand, so the tool is highly recommended.

After the left side air filter box is removed, you can now access the oil filter housing and remove the cap with the special filter housing tool. Use a joint on the socket to make the operation easier since access is poor down there. Pack a lot of paper and keep a tray on hand to avoid spilling oil when taking out the oil filter. Clean up all of the spilled oil, since it’s hot down there and we don’t want smoking and fires while the engine is running. Also use a small suction pump or syringe to get the little left over oil which lies in the house after the old filter is removed.

Oil filter housing M120 engine on w140
Empty old oil in the filter housing with a suction pump or syringe.

Then it’s time to open the bottom oil drain plug. You will need a large oil drip pan which can have at least 11 Liters. Beware the engine oil is hot and will come out with great force when removing the drain plug. Use plastic gloves to protect the skin and try to not loose the bolt into the pan when removing it. Expect about 10-10.5 liters of oil to drain out. It’s nearly impossible to drain it completely of 11 liters by just removing the plug as with most cars.

Draining engine oil from the M120 engine
Draining engine oil from the M120 engine.

When the oil has stopped draining after 10-15 minutes. Change the copper washer on the drain plug that comes with the oil filter kit, and the reinsert the drain plug. Do not over tighten since it will ruin the threads in your drain pan. Tighten the drain plug bolt to 30 Nm. It have happened a few times over the history that people have forgotten to insert the drain plug bolt and poured in the new oil which just lands on the floor. Do not stress and make this mistake!

New vs old oil filter
New vs old oil filter

Then replace the O-ring of the oil filter cap with the one that comes with the oil filter kit. Many recommends giving the O-ring with a coat of engine oil before assembly. I have no idea if it’s any useful, but I did it. It gives at least some less friction when installing the cap. On most cars it’s good to fill the oil filter hosing with oil so the first few rotations of the engine will have faster access to the new oil, but on this car it is not possible at all. Pouring new oil into the housing will just drain straight into the block. Also it is not possible to install the oil filter without it being attached to the cap itself, so there is no chance here.

The oil filter is installed by popping the oil filter to the cap and then inserted into the filter housing. Tighten the cap to only 25 Nm and it’s very important to not over tighten here since it’s made from plastic and easily strip threads. And a new cap is very expensive!

Drip pan bottom
Bottom of the drip pan. Inspecting for sludge and metal shavings can tell you a lot about the health of the engine. Here it’s all good and in good health.

Before poring in the new oil you need to know how much to add so you’re not over filling the engine. Simply adding 11 liters will most be too much. So you should always measure the quantity of oil which was drained. In my case it was slightly above 10 Liters. Also inspect the bottom of the oil drip pan, look for sludge and which can indicate overdue oil change interval and metal shavings which can indicate excessive wear in bearings and pistons. In my case it was no such indications and all is good.

Double check drain plug and oil filter cap is secured, then start poring fresh oil using a funnel to avoid spilling oil all over the engine. After you have filled the quantity you need, measure with the dipstick and inspect it’s not above maximum level. Some of the oil will need to get into the filter and you probably have to add slightly more after the engine have run a few minutes. Turn on the engine, see that you get good oil pressure, and inspect for leaks in the drain pan and around the oil filter cap. After the engine has run for a few minutes, turn it off and measure the level with the dip stick again. Add oil if necessary, but do not over fill. If too much is added then you need to remove the excessive oil with a suction tube.

Then reinstall the air filter box. Now It’s a good time to also change the two air filters on either side of the engine. No tools required here, it’s made like a drawer, like how you store your underwear at home.

Then take a short drive of 5-10 minutes, see that you have good oil pressure and that the engine feels normal. When coming back home, inspect for leaks around the oil drain plug. And remeasure the oil level with the dip stick, add oil if needed. Then you are done for another 15.000km.

Robs out!