Jimmy - that was my first thought as well, but the vac lines appear clean.

Looking more and more like a bourdon tube issue.

__________________
Bob
'82 300D Petrol B-G Metallic

sounds like you guys have it figured out.....another question....do you think any past mb owners have replaced the entire inst cluster including the speedo/odo instead of just the oil pressure guage side? ie junkyard parts.
I am looking at an 81 300d with 135k on the odo and the carpet on the drivers side floor is missing except the sides which look like they got a good dose of oil, also oil residue on floorboard. they probably had this same problem and I am not sure how they decided to fix it.
btw the brake pedal looks as worn as my 85 with 260k but the accelerator pedal looks brand new????

__________________
83 TD wagon "Madge" PO's given name. 410k (150k engine)

I have now confirmed the issue is a leaky bourdon tube.

I believe a very slow leak has existed for sometime, as I noticed the oil-soaked sound insulation about 6 months ago. I attributed it to a leaky vac shutoff that had been repaired by the PO and never fully cleaned up. It never dripped until.......

I changed to Mobil-1 synth in the crankcase two months and 1k miles ago. This seems to have accelerated the leak to the point that dripping started 2 weeks ago.

Anyone have a used cluster for sale?

__________________
Bob
'82 300D Petrol B-G Metallic

My third Mercedes, the 123 200 in my sig, had this problem. It was so severe I actually had oil pooling between the plastic cover of the instrument cluster and the guages themselves. As the car turned corners the little pool of oil would flow from one side of the cluster to the other. Quite amazing what it did to the carpet. I had the oil pressure gague replaced but sorry that was some years ago and I cant remember how much it cost.

- Peter.

__________________
2021 Chevrolet Spark
Formerly...
2000 GMC Sonoma
1981 240D 4spd stick. 347000 miles. Deceased Feb 14 2021
2002 Kia Rio. Worst crap on four wheels
1981 240D 4spd stick. 389000 miles.
1984 123 200
1979 116 280S
1972 Cadillac Sedan DeVille
1971 108 280S

Peter - this is a fairly standard human defense mechanism. Whenever I drop boatloads of money, I too get all amnesia-like

__________________
Bob
'82 300D Petrol B-G Metallic

Get on eBay- you can find entire used instrument clusters and just the fuel/oil/temp guages themselves
prepare to fight however, as everybody and their mother snipes on the instrument clusters and pushbutton CCUs, it's really annoying
otherwiese Perf Products have them for around $600(just the fuel/oil/temp guage) or if you Google search
I found new VDO units for around $375 at this one website but I can't remember it now
Your best bet is eBay or some kind soul here on the forum
I'd give you my old one but it's a leaker

__________________
'02 BMW 325i
'85 300D 450k
'93 190E 2.6 170k(killed by tree)
'08 Ducati Hypermotard 1100S 6k
'06 Ducati S2R800 14k(sold)