I just bought an '83 300D AT 172k .

Where to begin! So far I really enjoy the car. It rides well on the highway for a 30 year old car, and the new tires have helped with that. The entire 'air filter assembly' has been removed in favor of a cone-style filter mounted to the front of the turbo; a temporary solution for now. Blow-by is captured by a makeshift series of lines. I mention that as it *could* factor in, but that is unlikely.

I have put about 1,200 miles on the car. I've noticed that there is a vibration that I cannot diagnose, and I've done some research here on the forum and have not found what I think to be a description of the noise.

The noise 'sounds like' a wheel bearing/hub might sound, but is unrelated as it continues to some degree even with the car at idle.

To me, it seems like a 'harmonic balancer' type of sound, like one of the accessories has bad bearings, or perhaps something even more nefarious located inside the block like the crank or something.

To some extent, the 'waves' of the vibration get closer together as RPMs increase, but they never really become any closer than about 1 second apart.

My attempt at onomatopoeia is: wob [one second] wob [one second] wob...etc. It's a very 'deep' sound and as I'm driving down the highway at ~65 mph, if I lean close to the windshield I can hear the sound much better (resonating off the inside of the windshield?).

Any guesses as to what this could be? I thought perhaps it was related to the driveshaft/flex discs/centering cone/etc. but it continues to some extent while at idle, as I mentioned above.

Thanks all and I look forward to interacting with you as I go through this car and fix/upgrade/maintain it!

JD

Welcome.

Any way to record this sound?

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83 SD

84 CD

Yep a recording would maybe help. So it's a wave sequence, does the waver go completely away between 'wobs'? Is it more than sound, ie you can feel it in your hands, the seat of your pants, both, neither..? Do you have a mechanics stethoscope?

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1985 300D-189k The 'UD', Ivory and Pinkamino
1979 300D-211k Dark Gray, Parchment
A 1980 Harley-~166k and
A 1994 Ford diesel pickup-349k and
A 1990 gasser Volvo wagon-145k

... as difficult as it is, you may want to unhook all your belts, and see if the sound goes away.
I REALLY wish I'd done this on my car... I now have to pull the head, and inspect the pistons, as well as drop the pan and fish out all the parts that blew when the vacuum pump took a dump...

don't let it happen to you. find the noise NOW!

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Hi, welcome to the forum. I am up north in Cicero, along the east shore of the mighty Morse Reservoir - center part of God's Country. Anyway, do check that noise out. It is a pain to take the belts off and listen, but at times it is a must. Both a tired vacuum pump or a worn and (dare I say loose) big nut on the vibration damper are problems well worth looking at when you are looking for strange rumbles. If it continues whole the car is not moving, eliminate the driveline - it is not the problem. It could be bad motor mounts, so flat and oil soaked there is really no support left and then you could be getting a vibration that resonates through the engine area.

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Junqueyardjim
Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important. C.S. Lewis



1983 Mercedes W123 240D 4 Speed 285,000 on the road with a 617 turbo, beautiful butter yellow, license plate # 83 240D INDIANA

2003 Jaguar Type X, AWD. beautiful, good mileage,
Mom's car, but I won't let her drive it!

I was thinking about motor mounts too like Junqueyardjim. It can cause a pulley to skim along a fan shroud and other annoying things.

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BENZ THERE DONE THAThttp://www.peachparts.com/shopforum/...c/progress.gif
15 VW Passat TDI
00 E420
98 E300 DT
97 E420 Donor Car - NEED PARTS? PM ME!
97 S500
97 E300D
86 Holden Jackaroo Turbo D
86 300SDL
(o\|/o)

like taking out the oil cooler lines, when the power steering pulley droops and cuts into it!~!

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Thank you everybody!

Jim: good to hear you are in Cicero on the mighty banks of Morse lol [which apparently will soon take a hit from the water company]. I might want to try and get together with you at some point if you'd be up for that!

All: I *do* know that the alternator belt is stupid loose because I can see it 'flop around' at idle. IDK if it's just an old belt or there is a tension problem. One more thing on the list!

I was going to do some work today but the air here in Indiana is barely breathable at the moment it is so damn hot and dry. So...perhaps tomorrow I can take some of your advice/s.

I highly doubt I can get a recording of the noise because it's one of those things that even other people in the car can't hear. The ole 'well it just sounds like that cuz it's a old deezil dummy!'.

Vstech: sorry bout your motor! I hope it all turns out well in the end.

Wildest: I don't have one...yet. Maybe this is my excuse to purchase one.

More to come in the next several weeks...