Hey There,

After a 300 mile trip last weekend my '80 300SDs oil pressure gauge started vibrating (the needle that is). I suspect that the gauge is faulty, but thought I would check with the masses to get some second opinions.

The needle reads the pressure - that has not changed. It idles around 1.5-2 bar and pegs directly to 3 bar upon accelleration. BUT, the needle now jiggles/vibrates very quickly enough to cause an audible buzz. The vibration consists of rapid movements of about 1/16 of an inch back and forth while indicating general pressure readings What's up? I can live with the buzzzzz, but should I worry about the oil pump causing a pulse to make the gauge act the way it does?

With Luck,

Vegerl

Mine has done that before, so your not alone. As you said, mine only does it after driving a few hundred miles at a time. I've never been able to find out what causes it. Hopefully someone will chime in.

There is an old TSB on this issue. The fix was adding a restrictor to the oil gauge line, but I have never heard of anyone actually installing it. Most people just learn to live with it.

__________________
Palangi

2004 C240 Wagon 203.261 Baby Benz
2008 ML320 CDI Highway Cruiser
2006 Toyota Prius, Saving the Planet @ 48 mpg
2000 F-150, Destroying the Planet @ 20 mpg



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I've had the same issue, and I've heard of the restrictor modification. After replacing my gauge (because of an oil leak), the issue went away. My understanding it is a "normal" issue and is just annoying. Mine would also only do it after a couple of hundred miles of steady highway driving.

I have a 93 300d 2.5..and I am convinced there are demons in the instrument panels. One day they jiggle the next day they dont. Just keep an eye on the thing...and you may find that there is only a little gremlin in the thing. Guess the Germans should have gooten the japanese to configure their instruments.

thats a scary thought

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have no worries.....President Obama swears "If you like your gun, you can keep it

Is there a restriction valve or dampener of some sort on these guages? My aftermarket vac and turbo boost guage have a series of small orifices that is supposed to dampen the needle from vibrating.

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82 300D....went to MB heaven
90 350 SDL....excercising con rods

You are lucky that the demons are only in your guage cluster. I have a 64 bug that I swear fixes itself. Cars have souls!

__________________
82 300D....went to MB heaven
90 350 SDL....excercising con rods

It's my understanding that a modification was available to install an orifice in the oil line connection to the gauge. I thought about making one, but I never bothered.

When I first bought my car from a dealer with 75000 miles on it mine did this when it was driven for long periods of time the mercedes dealer put a nylon rerstrictor inside the line right where it connects to the gauge, never had the problem again.

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84 300 Turbo / 320,000
96 E300 D / 55,000

Got it! attach cigar hose in line.

__________________
82 300D....went to MB heaven
90 350 SDL....excercising con rods