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OK this D.I.Y. Post should aid you in a couple reapairs on your 2001 C240, but should apply to the 1999-2005 c240's as well.

Background before starting, my Check Engine light was on and my indications from the car were poor pickup or slugglish/surging acceleration. Like it wants to go smoothily but then choked a bit. After the car warmed up it wasnt so bad, but still present. Also my Codes given were Bank 1 Fuel Trim & Bank 2 Fuel Trim.

Replacing your MAF - AMM - MAS (Mass Air Flow - Air Mass Meter - Mass Air Flow : Sensor)

I did all 3 of these today. I have no experience with a Mercedes Benz, just a good working background in Mechanical work. It took me 3.5 hours to do all 3 repairs. I used a mechanics bay at work, that is provided by the Army. All tools and lifts.

Also I am NOT a MECHANIC, but these techniques should work for your c240. If you find any errors in this guide please post, it only helps us all.

ONE LAST THING. After I reconnected my battery I got a ESP MALFUNCTION - ESP - Electronic Stabiliy Program Not found or Not installed.

To correct this. Start the car. turn your wheel full left, then full right, then full left. Turn off the engine, and restart.
This technique Reprograms the ESP.

TOOLS Needed:
1 - Standard Flat Head Screw Driver
1 - 10mm socket and socket wrench and 10" Extenstion if you so choose.

Parts Needed:
1 MAF (Will be refered to as MAF for the rest of the post)

REPAIR:
Use the 10mm Socket wrench and remove the Negative and Positive Cables.

Remove the plastic intake tubes, just compress the tubes and they pull off.

Remove the front Engine cover. Pull the end closest to the front up the car up then toward you.

Remove the Rear Engine cover. Pull Up the front and then the rear end.

Remove the plastic ring around the top of the MAF.

Unplug the MAF

On the Back of the MAF there is a metal clip, I used my finger to pry it back, but you could use a screwdriver.

Remove the MAF and replace with new one.

Reconnect the Cable.

Attach Plastic Ring.

*At this point you can reconnect your battery and see if
your check engine light is still on.

DONT ERASE YOUR CODES BEFORE STARTING!!!
Ok if the MAF is the cause of your CEL (Check Engine Light) then it will go out on start.
(Keep in mind that your allowing unfiltered air into your engine so this should only be used for a quick check)

If your CEL doesnt go out your MAF may not be the problem.
Now that this is finished you would reinstall all covers and Done!

SPARK PLUG REPLACEMENT:
TOOLS NEEDED:
1 - Torx Socket... Not sure on the size.
1 - 3" Extention 3/8" Drive
1 - 3/8" Drive Socket Wrench
1 - 17mm Spark Plug Socket
1 - Spark Plug Boot Removal Wrench
Pen & Paper

Parts Needed:
12 - Spark Plugs
1 - Gapper
1 - container of Anti-Sieze
Rags.

REPAIR:
Use the 10mm Socket wrench and remove the Negative and
Positive Cables.

Remove the plastic intake tubes, just compress the tubes and they pull off.

Remove the front Engine cover. Pull the end closest to the front up the car up then toward you.

Remove the Rear Engine cover. Pull Up the front and then the rear end.

Now just as a tip I started with the passenger side of the engine, because it has more room you'll find this side of the engine is a bit easier to work on and if you can do it on this side your not going to be able to finish the other.

Ok before your start verify the battery is disconnected.

Draw a diagram of the wires so that you dont forget.
remove the Torx bolts from the 3 Coils on top of the Valve cover.

Remove the top coil connection cables
start in the front of the car and remove the spark plug boots.

KEEP COILS IN ORDER. It shouldnt matter IMO, however IDK if it does and I wouldn't try it.

Ok just as a hint your first 3 plugs from front to back do dont have to take you socket apart,

But 4 & 5 you'll have to seperate your extention from the socket in order to get it on the Plug.

The last spark plug is a bit of a pain. You will have to put the socket on the plug, then the extention, then the socket.

When you remove the last plug you will have to take it all apart to get it back out too.

Gap your new plugs, apply Anti-Sieze to the threads and install.

Replace coils boots(They will click when they are on all the way) and install coils from back to front.

Replace top connections on the coils. Done.

I would suggest reconnecting your battery at this point and starting your car. Only Because if you didnt get your spark plug boots back on all the way that cylinder may not fire and it would be alot easier to troubleshoot.

Same install technique on the Right side of the engine. (Be sure to Draw the diagram out again because its different on the Right side.)

Once done with both sides reinstall engine covers and intake tubes, and reconnect battery.


CHANGING OIL:

TOOLS NEEDED:
SMall MM Socket (Smaller than 10mm, not sure on size)
Socket wrench
1 - 13mm Socket for Drip Pan
Drip Pan (Capable of holding 8.5 qts)
Jack or Lift

Parts Needed:
9 - 1 QT 5w30 FULLY SYNTHETIC Oil I use Mobil 1
1 - Filter for C240 (Comes with 4 or 5 rubber seals various sizes)

OIL CHANGE:
Just to let you know I used a Lift to do mine. Make things so easy.

OK. To start let your car sit for at least 10 mins so most of the oil is in the oil pan.

Remove the Oil filter cap, located on the front drivers sized of the engine compartment, just in front of the oil cap. While your there, remove that cap as well.

Be sure to set some rags down so you dont get oil everywhere.and pull out the cap, which kinda look like a
Turkey baster.. LOL Anyway pull that bad boy out and set it in your drip pan and remove the filter.

Raise the vehicle and remove the rear engine skid plate. (There are 6 screws to get this thing off)
set aside the skid palte and screws and exposed now is the oil pan and 13mm oil pan bolt.
Set your drip pan in place and remove the bolt. Allow oil to drain.

Replace Bolt and skid Plate.

Lower vehicle. Install new filter.

On Filter cover remove 1 at a time old seals and replace with new ones that came with your filter.

Relace Oil Filter cap.

Fill with 8.5 Qts of Oil.

Turn key to the 2nd position and page through to the oil page and check level. If it says ok.

Replace Oil cap.

And your done.

Again if you find any errors please post.

NeV
 

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This is a very detailed guide. Great post man. One thing you should do is add photographs, if you have any, but I really think this thread should be pinned. Talk to Buellwinkle about that.
 

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My only problem is, you list three things you needed to change: MAF, AMM and MAS. You called the MAF a Mass Airflow, the AMM an Air Mass Meter and the MAS as a Mass Airflow: Sensor. As far as I know, the MAF is a Mass Airflow Sensor. So what is the difference between the two?
 

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Great post. On the plugs......I have an '04 C240 but should have the same gap settings as the '01. Can anyone confirm the gap settings? The OEM plugs are pre-gapped at 1mm from factory. I believe this is our gap setting. Is this correct or do I have to gap them?
 

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Discussion Starter #7
Great post. On the plugs......I have an '04 C240 but should have the same gap settings as the '01. Can anyone confirm the gap settings? The OEM plugs are pre-gapped at 1mm from factory. I believe this is our gap setting. Is this correct or do I have to gap them?

Any Autozone should be able to tell you the gap, but yes the same series engine should have the same gap.:thumbsup:
 

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Guys, I'm doing my own oil changes now and I hear you when you cringe at the price of the oil/quart. I get a discount through my buddy's business. He can set you up as a customer and you can get the oil for $6.48/qt. PM me if you're interested.
 

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This is a great post and has saved me a lot of bucks. I followed the instructions you listed for the plugs and they are perfect. great post buddy
 

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Great!

2001 C240

Thanks for posting this! Unfortunately, I just got ripped off having a mechanic replace my spark plugs and Mass Air Flow Sensor and fuel filter for over $1000.

From now on, I'll do whatever I can myself. I changed my own oil for about $60 when the mechanic (not the dealer) was going to charge me $176. It's amazing how much extra they charge simply for the name.

THANKS!
 

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This is a great post on changing oil - thanks.

The only thing I can think of (but I'm not sure about - haven't done an oil change on my MB yet) is:

Does the oil pan bolt have a washer or some sort of seal? If it does then it needs to be replaced as well.

My old diesel Pajero had a washer on the oil pan bolt and after every oil change (every 6000km - 10000km) the washer had to be changed with the oil - some mechanics may not do this - but I know from experience that you will get oil drips if you don't. *once again, not sure if this applies to MB's.
 

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I have not find the Oil pan bolt after unscrew 6 from cover panel.
Does someone has a picture or something to help me out.
Please.
--JT
 

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Thanks so much for all of the Info. I tackled the Spark Plugs and Fluid Changes and your post was so very helpful on my C320.
Now, where is that pesky Cabin Filter located??
 

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Don't forget, that when you disconnect the battery, the A/C stepper motors lose memory position, therefore it is recommended that you resynchronize the stepper motors (only with the SDS). This we have been seeing in that it is the main cause for the "ticking/popping" noise from the dash board on the 203 chassis. This is due to the stepper motor remembers the LAST position, and therefore when you reconnect the battery and the interior CAN wakes up, the motor overruns and snaps the inner area of the motor arm, creating the noise.

Disconnect the battery???

Resynchronize the stepper motors...

Otherwise, this post was great!

Happy Benzing!!!
 
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