vesna castillo

hi i have been reading old posts related to my problem.... i have this weird sound too that has been previously described here in old posts as something like pebbles shaken in a plastic bottle at low rpm. i had my transmission overhauled i think august because it gave up then i get my 1978 300d back transmission fixed but with this crazy sound that seeems to be loud when i am sitting in the driver's seat and it comes out at 40 kph then seems to decrease in volume when i go to 60kph. then when i decelerate to a stop , it lags behind a few seconds then it is gone.... my mechanic thinks i am crazy or i just want to torture him with more work but i insisted that he check her out ... i just got her out today and it is still here.. i got the sound back like less than a kilometer from my mechanic's place...i just decied to bring her home and to post this .... he told me earlier he adjusted my valves , he thought it came from there and he opened the transmission again but saw no problem.....he checked this differential thing dunno what that is but he said it was okay.....anyway it is such an annoying sound. i am so worried that they will try to find a needle in the haystack and make me spend so much again then in the end the sound is still there. the mechcanic is experienced in benz but i feel that i need your expert opinion on this as he could not figure it out.... i got lost with the old posts about ball joints and stuff that could be causing the problem. my mind is just so clouded that i really need help and more explaining onwhat is probably going on.... please help.. thanks very very very much.......

300Dman

Mine is a different Engine but when I first got my Car it had ratteling sounds. One of them was the Bolt on the upper Timing Chain Guide was loose and the Guide would sometimes rattle.
See the attached Pic. The bolt is to the left of the white arrow.

The other really bad rattle I had was a loose Air Filter housing. I have read the mount bushings go bad and the Metal frame that is the mount sometimes cracks.
Anyway I got both tightend up and no more sound from them.

While your mechanic will not be able to hear it as well as you you might barrow a tape recorder and record the sound so he will at least know there is a sound.