Problem with acceleration in a 2002 C240-Please Help
MBWorld Fanatic!
Joined: Jan 2005
Posts: 2,848
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From: Orange County
2005 C Wagon (No snickering please!)
What is that noise that sounds like an electric drill? Is the engine speeding up and slowing down by itself, or is it being goosed?
First things on my list are:
a. Have the spark plugs been changed? When, and were they the right ones or did the counterman say "these will fit her?"
b. Is there a vacuum leak someplace?
First things on my list are:
a. Have the spark plugs been changed? When, and were they the right ones or did the counterman say "these will fit her?"
b. Is there a vacuum leak someplace?
Junior Member
Joined: Mar 2012
Posts: 45
Likes: 0
From: Beverly Hills ,California
C240 Mercedes Benz
1.) that noise is the engine it actually sounds like its coming from the MAF area like a loud winning noise. the engine is speeding up and slowing down by itself--- it idle's so low where all the lights turn on on the instrament cluster and its about to die out then by some grace of God it stays on a little longer it does that over and over again. Till it idles so low it just dies out.
2.) The coil packs have not been replaced the car was running fine 1 day ago. Starts up with zero issues. Cranks right up.
3. whats the best way to check for Vacuum leaks I usually spray thorttle body cleaner spray around the PCV pipes and see how the engine reacts.
2.) The coil packs have not been replaced the car was running fine 1 day ago. Starts up with zero issues. Cranks right up.
3. whats the best way to check for Vacuum leaks I usually spray thorttle body cleaner spray around the PCV pipes and see how the engine reacts.
Super Moderator
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Is the car storing any codes - have you checked with an OBDII scanner? You can store codes without them reaching threshold & triggering a CEL.
So thats's step No one. We need to see if you have any misfire codes, P0300, 301, 302 etc.
Then we need to check plugs, coilpacks & plug wires - especially if you are storing misfire codes.
Then we need to check fuel pressure on the rail at the schrader valve. It should be > 3.8 bar.
Is the Airfilter housing down tight over the MAF?
Movie has memtioned checking for vacuum leaks.
Only once these basics are checked is it worth chasing down TPS (throttle position sensor) etc.
When last did this car have a new fuel filter?
Is the transmission behaving normally? That high pitched whine almost sounds like the start of a torque converter failure. These cars do make a bit of a whine but that's excessive.
So thats's step No one. We need to see if you have any misfire codes, P0300, 301, 302 etc.
Then we need to check plugs, coilpacks & plug wires - especially if you are storing misfire codes.
Then we need to check fuel pressure on the rail at the schrader valve. It should be > 3.8 bar.
Is the Airfilter housing down tight over the MAF?
Movie has memtioned checking for vacuum leaks.
Only once these basics are checked is it worth chasing down TPS (throttle position sensor) etc.
When last did this car have a new fuel filter?
Is the transmission behaving normally? That high pitched whine almost sounds like the start of a torque converter failure. These cars do make a bit of a whine but that's excessive.
Last edited by Glyn M Ruck; Mar 7, 2012 at 07:41 AM.
Junior Member
Joined: Mar 2012
Posts: 45
Likes: 0
From: Beverly Hills ,California
C240 Mercedes Benz
In response to GLYN M RUCK
the CEL came on before but then I reset the computer well i unplugged the battery cables for about 10min and then rehooked them up and the CEL was off. Im guessing the code is still stored in ECU ( the computer)
any advice on how to check for Vacuum leak's i had one line break the one that goes from the L Neck like between the MAF and Throttle Body there is a hose that Y's off to like a fuel line hooks up to it or something and it goes to the Driver side Valve cover. that hose cracked so i cut it and put a adapter to replace it with some extra hose and added hose clamps.
It was driving fine until i cleaned the MAF sensor and the Throttle body then it went from bad to worse. i went and baught a new MAF sensor and it didnt help i reset the computer again and disconnected the battery before i uninstalled the and installed the NEW MAF.. it didnt help out much at all car didnt even wanna crank up. i put on the old MAF sensor and it cranks up pretty quick but sounds all crazy and shuts off.
where is the TPS located at ?
GUYS THANK YOU SO MUCH FOR HELPING ME OUT !!!! 100% thank you for your patience!
any advice on how to check for Vacuum leak's i had one line break the one that goes from the L Neck like between the MAF and Throttle Body there is a hose that Y's off to like a fuel line hooks up to it or something and it goes to the Driver side Valve cover. that hose cracked so i cut it and put a adapter to replace it with some extra hose and added hose clamps.
It was driving fine until i cleaned the MAF sensor and the Throttle body then it went from bad to worse. i went and baught a new MAF sensor and it didnt help i reset the computer again and disconnected the battery before i uninstalled the and installed the NEW MAF.. it didnt help out much at all car didnt even wanna crank up. i put on the old MAF sensor and it cranks up pretty quick but sounds all crazy and shuts off.
where is the TPS located at ?
GUYS THANK YOU SO MUCH FOR HELPING ME OUT !!!! 100% thank you for your patience!
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Junior Member
Joined: Mar 2012
Posts: 45
Likes: 0
From: Beverly Hills ,California
C240 Mercedes Benz
TPS is located on gas pedal?
let me look now as im actually out here looking at the car now i took different pics of the MAF , all vaccum hoses, and area around the Throttle body i took pics of the inside and around the Throttle body.
I have a question is it bad to relieve pressure from the Valve on the fuel rail? i was letting out fuel to see if it had pressure. what it does now is it acts like its trying its best to stay on and not shut off. but suffers for Air like its gasping for air it makes that loud chocking noise if you see the video you can hear it Gasping from the MAF / Throttle body area. its kinda pathetic . hurts to see my car suffer so damn much..
I have a question is it bad to relieve pressure from the Valve on the fuel rail? i was letting out fuel to see if it had pressure. what it does now is it acts like its trying its best to stay on and not shut off. but suffers for Air like its gasping for air it makes that loud chocking noise if you see the video you can hear it Gasping from the MAF / Throttle body area. its kinda pathetic . hurts to see my car suffer so damn much..
Junior Member
Joined: Mar 2012
Posts: 45
Likes: 0
From: Beverly Hills ,California
C240 Mercedes Benz
cilvest
thank you what im going to do tomorrow is replace my fuel filter! see how that helps and see how it acts. do i need to do anything after i replace the filter anyone?
im guessing the electric pump should feed enough fuel to keep the air out and fill the lines right?
im guessing the electric pump should feed enough fuel to keep the air out and fill the lines right?
Junior Member
Joined: Mar 2012
Posts: 45
Likes: 0
From: Beverly Hills ,California
C240 Mercedes Benz
PLEASE HELP GUYS
i took pictures of the throttle body area MAF etc please help me with the PVC vaccum hoeses and what they do which play a major role in the the idleing of the vehicle. also whats that electric unit in black attached to the side of the throttle body!
Super Moderator
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Please get hold of an OBDII scanner & read what codes are being stored. It stops a lot of guesswork. The black thing attached to the throttle body is the actuator. These cars have a "fly by wire" throttle. You press the gas pedal & the TPS sends a dual signal to the ECU. The ECU then sends a specific voltage to the throttle body actuator to open the throttle plate.
Junior Member
Joined: Mar 2012
Posts: 45
Likes: 0
From: Beverly Hills ,California
C240 Mercedes Benz
I aquired a OBD-II scanner and my question is where is the OBD-II data link located at ? By self observation and knowledge I know usually its located under dashboard by hood release cable below Parking Brake release lever in that area but i dont see anything at all. i will post up some pictures asap!
Junior Member
Joined: Mar 2012
Posts: 45
Likes: 0
From: Beverly Hills ,California
C240 Mercedes Benz
ok i found the OBD-II data link seems someone stuffed it up into the underdash I hooked up the OBD-II scanner using the Actron CP9125 basic model the code i recieved was P0112 on the scanner it has a butt load of faults as i scrolled down after seeing the code it says MIL ON, MONITORS , 6 Inc , Catalyst , Evap, Sec Air ,02 Sensor, 02 Heater, EGR , 3 Ready , Misfire, Feul, Comp......
all these are the things that popped up under that code.
all these are the things that popped up under that code.
Junior Member
Joined: Mar 2012
Posts: 45
Likes: 0
From: Beverly Hills ,California
C240 Mercedes Benz
i going to post pics of what i found my spark plugs are soaked with black sutt and fuel it was pretty horrible! i just got back from the store and baught Iridium NGK spark plugs 100. dollar for 12 spark plugs.
Junior Member
Joined: Mar 2012
Posts: 45
Likes: 0
From: Beverly Hills ,California
C240 Mercedes Benz
My Spark Plugs are horrible idk if its effecting my IDLE etc?
after a little brain storming i was like i know no one has ever changed the spark plugs on this car well i pulled them out and it smells like fuel i can smell it excessivly from the spark plug holes! the sprak plugs are black and filled with fuel i went and baught all new spark plugs going to intstall them and see how that effects my cars performance. after running it and seeing how it reacts ill pull OBD II codes again.
Super Moderator
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
What a mess. There are multiple issues here. I've owned a C240 - I know them well. See what the new plugs do & try & get some decent readings of codes.
If I was to make a WAG I would say you have a shot MAF & clogged Cat's.
Let's do this one thing at a time. Do the plugs. Cancel codes. Try & drive the car & tell us what codes get stored.
If I was to make a WAG I would say you have a shot MAF & clogged Cat's.
Let's do this one thing at a time. Do the plugs. Cancel codes. Try & drive the car & tell us what codes get stored.
Junior Member
Joined: Mar 2012
Posts: 45
Likes: 0
From: Beverly Hills ,California
C240 Mercedes Benz
What a mess. There are multiple issues here. I've owned a C240 - I know them well. See what the new plugs do & try & get some decent readings of codes.
If I was to make a WAG I would say you have a shot MAF & clogged Cat's.
Let's do this one thing at a time. Do the plugs. Cancel codes. Try & drive the car & tell us what codes get stored.
If I was to make a WAG I would say you have a shot MAF & clogged Cat's.
Let's do this one thing at a time. Do the plugs. Cancel codes. Try & drive the car & tell us what codes get stored.
Super Moderator
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Have you replaced the plug wires?
Please check everything I listed in post #29. Do you have adequate fuel pressure?
We need to go methodically through all these items.
Please check everything I listed in post #29. Do you have adequate fuel pressure?
We need to go methodically through all these items.
