Everyone. I need a real quick answer to a question. I usually have time to search and research but in this case I am looking at a car (83 300D Turbo) that I really want and need a quick answer. The car I am looking at has a leaking oil pressure gauge. I understand that there are things that can cause this and not be the gauge itself but when buying I want to assume the worst and hope for the best. What is the average cost for a used gauge? My local pick a part has 4 190' ranging from 85 to 96, a 76 240, a 79 300, and a 96 E class. Will the oil pressure gauge cross over from any of these cars? I don't mind if the low fuel light works different as long as it reads well enough that I don't run out when it says 1/2 tank. The price is real attractive on this car and I want to have a idea of how much it will take to fix this up. Thanks in advance and I look forward to introducing myself here with a new car.

Whole gauge cluster should be around $20 at a P & P. Any 123 diesel cluster should work.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

It could be as simple as a loose fitting from the oil line to the back of the guage. 10mm fitting could be loose causing the leak. You'll have to pull the cluster to examine the back of it, self explanatory once you're in there. Plenty of instructions on how to remove the cluster on this forum, but it's easiest to just push it out from behind, once you remove the panels under the dash. The dash lights probably don't work either, so you'll have to get it there anyway. Just buy the car and add these little jobs to the many you should do to get the car sorted out. They're "mostly" all fun and easy.

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'82 240D automatic to manual (sold)
'84 300D (sold)
'12 MINI CooperS Coupe
'71 Triumph Stag
'76 MGB
'08 BMW 535XI wagon
'12 VW Golf TDI

Thanks everyone. I plan to buy the car no matter what. The guy I am buying it from is the second owner and has all of his service records dating back to 1986 when he bought it from the original owner.
One last question. Will the gauges (except speedo) from a 85 to 96 190 or E320 work? I expect the tach and speedo to be car specific but the fuel, amp, and oil could be interchangeable. I also thing that the gas 190's had a vacuum economy gauge as well. It might be cool to hook that up to the trans vacuum signal that is designed to mimic the throttle position signal even though a diesel has no manifold vacuum.

I wouldn't worry about that, its an easy fix, he's probably going too let the car go a little cheaper if its not perfect, right?

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1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

To my knowledge, you need an instrument cluster from a W123. Other gauge clusters do NOT interchange.

Sincerely,

Packman

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83 240D - 4 speed manual - Manilla Beige
189K miles, Tachometer mod, cool wooden shift knob from PeachParts, CocoMats, Original factory paint, manual windows, manual sunroof. Starting to add AudioWrap to this car too!

So cheap that I can not mention the price here for fear of causing a riot

82-85 300D's are showing up in the junkyards regularly now, making once high dollar parts real cheap now. It is a simple plastic tube to the gage from the bottom of the oil filter. I wish they had made it 4" longer so one could pull the cluster out a little more when working on it. Do so, if you replace the tube.

Why do you think it is the pressure gage/tubing that is leaking? Usually, when oil drips on your right foot it is because the vacuum "stop valve" on the injection pump is leaking and sucks oil up to the vacuum switch on the side of the key switch. A new stop valve costs $50 to $150 and is fairly easy to change if you have a ratcheting box wrench (10 mm, I recall).

123 guages are not necessarily interchangeable between certain years, either. There are differences in the tach. and speedo. connections.

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'83 300D, 126K miles.

But the oil pressure gauge is the same right?

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

I have a 123 F-O-T gauge available if you need it. $20 plus shipping. Pm me if you want it.

It works, you will need to transfer the rheostat and a couple bulbs over from your other module.

It is from a pre 1980 123, the units are American instead of Metric but it works right either way.

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The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech

One saying we use highly, there is no such thing as a cheap Mercedes!

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True so true! Repair techniques are rather straightforward and well documented though.

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Codifex
1981 240D ChinaBlue (Got her running with a donor engine.)
1983 300DTurbo w/sunroof.
1984 300TD manual sunroof. (Electrical Gremlins)

Fortunatly you usually can control the cost of replacement parts at this time. Pick and pulls, discount parts houses etc. The actual personal labour involved remains pretty much a constant though.

The oil/temp/fuel gauge is all one unit, not three seperate pieces that can be installed seperately.

From my experience, any 123 gauge will fit into another 123.
Gauges from another chassis model will not fit into a W123 chassis.

The gauge up to 79 was in psi and ferenheit. then 80 - 85 on Bar and "C".
the early low level fuel light is red in the early gage and the later one in orange.

As mentioned the gauge from PNP is about $20, the whole cluster with spedo
and clock and or clock/tach is around $35.

It would be best to remove the whole inst cluster to replace the gauge, and then would be easy to access and clean up the oily mess behind the dash.
Use a 13mm on the gauge and a 10mm open end for the oil line. yes it would be nice if any of the wires/cable or oil line were a bit longer for better access getting my hand behind the clister.

I had a leaky oil gauge back in 97 when I was getting baptized into the MB world. It was leaking on the left shoe/sock. took it to a shop to see what was going on???? easy fix, picked up the car in the afternoon with a new gauge. then it was sticker shock when I saw the bill. $344 for just the Gauge

Wish I knew about this Forum way back then.


Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works