I have a c240 2002 i want to ask something , if i put N(neutral) and let the car roll for a while and then if i stop or not when changing the gear back to D(drive) the car make a "bump" from the gear and then evrey thing is back to normal , all the driving in the car is normal nothing is bad exept when i roll the car on N and then put D. is this normal?

 

I would inspect the transmission mount. Is your problem only on a roll?

 

yes only when i roll on the (N) and then i putt (d) i happens, and then evrey things work fine !! strange if i put n on stop and then d nothing happen on when i put n and roll and then d

 

What is the reason for doing that? I'm not saying it in a bad way. I just want to know why you would be rolling in neutral and then put it in drive.

 

On a 2002 without the reflashable TCU this is probably normal if all mountings etc are in good condition. Software for these transmissions has improved over time. I think it is just the TCU not computing input shaft sensor data with output shaft sensor data quickly enough. The practice of freewheeling in Neutral is not a good one. Keep the car in Drive when moving.

 

please i think i get it but i have 2 questions:
1-what is a tcu
2-is there a new programs for it

 

TCU = Transmission Control Unit

As Glyn notes, sounds like the 02 model year TCU is not programmable, so you will just have to live with it.

I also agree with Karo, definitely check the tranny mounts. Although not a rampant problem, it is not un-common for them to fail.

Good Luck on it.

Greg

 

+1

 

Check the mount. If it's okay, then it's just the car being silly, like what Glyn said. I have the same problem too, but checked the mount and it's okay, so my car is definitely silly. Hahaha..

 

thx guys i will check the mounts today!!!

 

Isn't that bad for the transmission guys? Putting it in NEUTRAL and then DRIVE while its in motion puts a lot of wear on the transmission. I did it before and my transmission felt like it was going to brake into pieces. Mine also made a loud "thump" and the car jerked for a second.

 

Freewheeling in neutral is not a good idea. Fortunately with a Benz transmission at least the oil pump still works. With some US transmissions the oil pumps don't operate in neutral.

 

aha thx for this advice i didn't know it, but why they do something like this they cut off the oil pump in neurol !!! not a good idea! thx anyway

 

I've a 2002 c240 55,000mi. Had the oil changed at the local Benz dealer and the gas cap replaced. On my way home the too much oil warning came on. When I floored it it responded sluggish, and an ENORMOUS cloud of light-colored smoke came out the exhaust and it eventually died. It started right back up and I dropped it back off. Any and all comments would be greatly appreciated. I don't wanna get ripped off if they claim it's just a coincidence(and charge me for something else).

 

Yeah they're not suppose to fill your car all the way up with oil. When changing oil, what they need to do is leave about 0.3 to 0.5 quarts room for some of the oil that's already left in the oil line. I might be wrong.

I change my own oil all the time and I use Mobil-1 0w-40. Ever since, I had no problem with the low oil warning, knocking, or sluggish performance issues.

 

Yeah just start yelling at them if they try to say it was not there fault. Ask for hard evidence it was not there fault and also get mbusa involved early if needed as well as all managers/owners.

 

You would think a dealer would use the service dip stick to check the calibration and operation of the oil level sensor as well as checking their own work with regard to the correct amount.

You should have entered the dyno mode and taken a picture of the oil level shown in the MFD. That would end the static about "the oil level is fine" from the service manager. They have been known to CYA.

 

I have the same problem with my C240 2002, it was driving me crazy, until i stopped shifting into neutral and rolling the car.

Basically i was under the impression that shifting into neutral in traffic jams and on traffic lights reduces the fuel consumption.

Not anymore, although the fuel prices in Lebanon are sky high!

Khalil where are you from?!

 

I was under the impression that most modern cars are capable of coasting in drive without using fuel, but in neutral it would burn fuel. Could be wrong, though.

 

Just to respond to the original question, went to the dealer to diagnose some noises. They told me I had a lot of engine vibration coming thru the cabin and therefore needed new motor mounts and the transmission mount replaced. So I replaced them myself and the car drives so much better. these cars are great but you need to keep up on the maintenance. I ve learned that the hard way