I just got my car today and the oil pressure gauge is reading max at 3 (81 300 CD) is this correct??? is this not pressure and something else? ignorance is bliss but i plan on a rigid maintenence plan so this car will longer than me. any suggestions??

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Jeff SE PA
1981 300 CD 85K miles "Heidi"
84 El Camino (what an SS should have been in 84)
01 Jeep Cherokee lifted 3", goes anywhere

When started cold it should peg to 3 right away and stay there till warm, then once the engine is warm it should idle between 1 and 2 bar but instantly go up once accelerated.

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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

This is metric oil pressure, 3 bars. Idle oil pressure is usually somewhere around 1.5 to 2 bars, depending on operating temp and type of oil used. Engine should have maxed out oil pressure when running cold or anywhere above 1200 to 1500 RPM when running at operating temp. Operating temp is normal anywhere between 80C and 100C depending on load and ambient temps.

Also condition of engine clearances will affect all of the above.

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1961 190Db retired
1968 220D/8 325,000
1983 300D 164,150

If your oil pressure gauge pegs at 3 permanently, than the oil pressure sender unit, or the associated wires are defective.

Phil

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'95 E300 Diesel, 264,000 Miles. [Sold it]

Not to be a smart ass, but on the 123 the gauge is mechanical (oil line to the instrument) that will drip oil on your left knee if it fails like mine did.

Oops,

I should have read the year, and model more carefully

Phil

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'95 E300 Diesel, 264,000 Miles. [Sold it]

ok, update ... it's hangin around 2 and pegs even when slight pressure is on the gas. this is normal? she's getting her first check up and full fluid replacement this week, we are starting from scratch. Just got the Carfax report and nothing before 2003, is this right?

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Jeff SE PA
1981 300 CD 85K miles "Heidi"
84 El Camino (what an SS should have been in 84)
01 Jeep Cherokee lifted 3", goes anywhere

yes, your oil pressure gage is working ok. my old 300D (same motor as yours) did this, as does my 240D.

The worry point should be around 1 bar - Which it might do when the oil gets warm, if you search on here a bit you'll find the factory minimum (Which is like 0.7 or 0.5 bar at idle...), anything above that minimum is jsut fine. pegging out is okay, running the engine all day pegged out is ok too.

-John

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2009 Kia Sedona
2009 Honda Odyssey EX-L
12006 Jetta Pumpe Duse
(insert Mercedes here)

Husband, Father, sometimes friend =)

oil pressure - that is normal as the others have said. at 85k it must be in great shape! -- post pics !!

forget carfax- depend on your eyes and ears and the good folks here and all will be ok....

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

thanks for the advice guys you were absolutely right. I found the orig books in the glovebox all the way back to 2/81 when it was purchased in Oregon. Just got some fair pics ...... let me know what you think.
300cd side
300cd back
300cd int
300 cd int2
300cd side
300cd front

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Jeff SE PA
1981 300 CD 85K miles "Heidi"
84 El Camino (what an SS should have been in 84)
01 Jeep Cherokee lifted 3", goes anywhere

car looks good. remember, you have to floor it to get anywhere., and if it is slow off the line, look up a good indy mb mec to adjust alda for you.

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71 220D 169K wrecked
83 240D 118K sweet 4 speed
91 350SDL (one of the 60% good engines) 156K
84 300d (loaner to my sister) 189K
79 300SD (partswagen)
86 420SEL partswagen
70 220d (partswagen)
68 280s GASSER!!! under construction now
85 300sd 310K miles winter beater car retired
93 300d 2.5 turbo 168K wife's car
83 280SL euro 5 speed 155K
69 250S newest project 54K

going to meet him next week, been in biz since 1949 .. i remember the place as a kid .... he seems real upfront. gave me good advice over the phone before i bought the car.

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Jeff SE PA
1981 300 CD 85K miles "Heidi"
84 El Camino (what an SS should have been in 84)
01 Jeep Cherokee lifted 3", goes anywhere