I have a '79 300D and lately my car has been making a whining noise usually just in first gear, mainly when I accelerate. It only whines when I push on the gas. Sometimes it does it, sometimes it doesn't. I got some belt dressing stuff and sprayed the belts down pretty good, but that didn't really get rid of the problem. Do I need new belts or is it something else? I tried to look for cracks, but didn't see any on the belts. E-mail me at Toburen@ou.edu


Thanks.

May not be the belts or perhaps it is. Try having a friend give it some fuel with the hood up and you listening close by. Might just detect where it's coming from. Also with engine off make sure you cannot turn alternator pulley easily. When electrical system calls for charging especially belt may be slipping..That is more like a shreiking noise but does not last long usually. Belt loose again causes that.

And it was the belts, I think alternator. When I first had the issue I tried belt dressing but it did nothing. MB does not recommend using the stuff anyway. I got a new set of contenintals and it went away. I did have to retighten the alternator belt a couple of times. I either did not tighten enough or it stretched a little.

__________________
Sonny


86 190D N/A 2.5L Auto 265k "Ruby" -Sold-
79 300D 242k "Condi" my first -sold- RIP
2013 chevy sonic hatchback - had to for work

ganimal,
what are your humidity and ambient temperature levels ? suspect alternator belt may need adjusting...

__________________
1984 300D Turbo - 231k....totalled 11/30/07 RIP