attn: anyone who has noises when driving...

[Andrew C280]

After putting up with what sounds like exhaust resonation when driveing 60km/h at constant pedal pressure, I thought that my drive shafts need to be ballanced or there was something wrong with my tires, I took the car to my mechanic and he told me that when they replaced my transmission they put in the updated one which was a 5 speed so when your driving around in the city in "D" mode its running in top gear. Anyone who has a manual that tries to run in top gear while going 60km/h will know that its hard on the engine and could stall, my mechanics advice is to run the car in "4th" while driving in the city and it will run up to 130km/h when going out on the highway drop it into "D", he also told me that shifting the car like a manual will not wreck anything, and you can downshift as long as your not stupid and drop into "3" when going 130km/h.

[J Irwan]

I am confused..??

to my knowledge a 1997 C280 come with 5 speed auto tranny already.

When you have gear selector in "D" meanst that the highest gear would be the "5th" gear..

so it will shift automatically to the (5th gear) at optimal rpm and speed..


to cruise in certain rpm and purposedly put the gear in "4th" to avoid any vibration is ridiculous.

clearly there is an underlying problem that cause those vibration.
There shouldn't be any vibration even when you drive at 60km in "5th" gear.

The auto tranny control module is smart enough to shift to proper gear at the given rpm, shift and throttle positon (wide open throttle vs cruising a low speed).


I would check all the muffler hanger, see if there is anything missing or if there is anything that got overtighten.
(my wild guess, is that could be one of the hanger is missing, and the place where you have the car service put a fasterner, tie it. OR it could be someexhaust part touching the underbody when it's not supposed to)
The muffler should be hanged by rubber hanger. Hence the rubber won't transmit vibration onto the chassis.

Also did anything chance before you notice this vibration..?

Sounds like the mechanics doesn't really know what he's talking about.

without seeing your actual car, it would just be a "wild" guess trying to pinpoint the problem. If I were you I'd ask for a second opinion with another mechanics.


Regardz,

[Andrew C280]

Well the problem is fixed and my mechanic is not full of B.S. in 1997 some cars came with 4 speed and some came with the new 5 speed electroic transmission they where introducing them then.

all i was saying is that the vibration that i was feeling was related to low rpm and the tranny being in the highest gear normally the engine is running about 1500 rpm and in fith gear.

there is nothing wrong with my exhaust hangers once in the winter ice and snow built up ontop of my exhaust causing it to rattel the fender.

checked it out with the mercedes dealership and my independant mercecedes mechanic who is more than amplely qualified.

it makes total sense when you think about it maybe i am not explaining it right

i did have the transmission replaced due to trany failure by the previous owner

[J Irwan]

Originally posted by Andrew C280
Well the problem is fixed and my mechanic is not full of B.S. in 1997 some cars came with 4 speed and some came with the new 5 speed electroic transmission they where introducing them then.

all i was saying is that the vibration that i was feeling was related to low rpm and the tranny being in the highest gear normally the engine is running about 1500 rpm and in fith gear.

there is nothing wrong with my exhaust hangers once in the winter ice and snow built up ontop of my exhaust causing it to rattel the fender.

checked it out with the mercedes dealership and my independant mercecedes mechanic who is more than amplely qualified.

it makes total sense when you think about it maybe i am not explaining it right

i did have the transmission replaced due to trany failure by the previous owner


Regardless some 1997 came with 4 speed or 5 speed, what I was trying to say that the transmission should have not cause any vibration.


Anyway, you said it was fixed, then what was the problem....???


Regardz,

[Andrew C280]

poping it in "4" and leaving it there when driving in the city allows the tranny to up shift and downshift automaticlly, and seams to not make the sound any more, when i pop it into drive and do the same thing it makes the sound so i cant be drive shaft ballanceing, i checked the tires with bran new ones not that either exhaust is ok nothing broken.

i will try to take a video of what the car dose with sound but for now i will just pop in in "4"

if not they will try to adjust the tranny shift points, under full throttel with kick down it makes no vibration its just when running exactly 59km/h with hardly any throttel that it makes the nosie.

[J Irwan]

That's what I am trying to tell you..

60km/h is equivalent of 40mph and my car or any other mercedes, bmw, lexus,acura, and Audi with 5 speed auto tranny does not make any kind of vibration or whatsoever..

Clearly putting the car in "4th" is not a real solution.

I would try to get a 2nd opinion that's all. For all you know it could be a hidden problem that may lead to a major one.. (knock on the wood).

Just trying to help, that's all.

Regardz,

[Andrew C280]

yah i understand what your saying but no one knows whats wrong, dealer, independant, you know when you down shift or engine break, it makes a sound like a transport truck. my mechanic assures me that it wont wreck anything. since i had the car from day 1 its had tones of problems I am slowly geting the car restored to its original shape and working order. its my first car and it awesome and i am not a millionair but i am wealthy, not bad for a first car when i get a real job when i am done post secondary school i might buy a new benz or bimmer. I am the kinda person that like to keep everthing in like new condition. now that i am not working 95 hours per pay period I am back to school now i can consentrate on my car alittle more

one thing i am wondering, is the drive shaft inserted into the tranny properly is there any alignment dots or anything and the other is what about the drive shaft bearing is it greaseable and i heard the drive shaft is two parts is this true ?

[Rocky]

Have you check the front and rear flex discs that is connected to the drive shaft? Those are semi problems with the w202 as well..check the tranny mount.

[mayagman]

I basically have the same exact car as you, and I noticed the same noise.
I put it on a lift and did some listening, and I'm pretty sure its coming from the intake. It only started happening after I put in my KnN drop-in filter. Im assuming the increased airflow made it start hissing a little under throttle pressure. I originally thought it was a washer vibrating somewhere on the underbody. But Im confident its the intake. Happens at 1500-2000rpm under light-ish throttle pressure.

[Andrew C280]

I lied i drove all around today in "4" still makes the noise but at 50km/h

[J Irwan]

Originally posted by Andrew C280
I lied i drove all around today in "4" still makes the noise but at 50km/h


hm....

did you hear only the noise, or there is also some vibration..?

I wonder what the culprit..??


Regardz,

[Andrew C280]

i only hear the noise its like a BBBBBBBBRRRRR