Would you care to educate us as to why you would not replace the oil pressure sender so that you would know what kind of oil pressure you have instead of driving 60,000 miles with it inop?

Kind of boggles my mind. (Unless of course the car is a POS and you're just driving it until it quits).

Cheers,
Wes

Oil pressure per se isn't the issue. It's the amount of oil pressure and conditions under which it is being produced.

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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

This is a problem my son faced recently on his Euro 1985 190E 2.3-16. First, since you get an indication of oil pressure on the gage, you don't have a broken chain drive to the pump. Once that breaks you don't get any sign of oil pressure. Next, you have to look at what could cause the symptoms you see. To assume it is the gage/sender is potentially fatal, kind of like the Three Mile Island plant operators looking at gages telling them really bad things were going on and then deciding that couldn't be the case and ignoring them....

In my son's case one of the chain guides came loose and got ground up on its way down to the sump. The resulting wad of ground up composite material plugged the pump strainer. There were other things, like pumping small metal fragments from the backing, and obviously some of the ground up composite, that have damaged the pump and made the pump output noticeably lower than before the incident, but it still works fine. The guide was knocked loose by a failing chain tensioner, and this failure probably saved the engine. He replaced the faulty chain tensioner with a new, updated one, and the chain is no longer a liability. He drives with a cautious eye on the oil pressure gage though.

The electrical pressure sensor is relatively easy to replace - once you get a wrench in there. We bent up a Craftsman 17mm combination wrench to fit and it worked fine. We determined the electrical sensor was not the problem by hooking up a mechanical gage from the high school's auto shop. But, we replaced the sensor anyway as it had some audible parts rolling around inside, and a new one didn't.

His oil pressure never went to zero, it dropped to about 1.5 bar while idling once warm, and then, when you gave it gas it dropped further as the flow rate restriction on the inlet starved the pump. There was no way we would run the car this way, so we embarked on an investigation that resulted in the pan being dropped and the sump/pump strainer being cleaned out. We also replaced a relief valve at the pump, thinking it was possibly compromised. Now the car runs with a lower oil pressure at idle - 190E 2.3-16's idle at 3 bar, or the needle pegged, regardless of oil temperature, normally - around 2 bar - and about 2.5 bar when the engine is under load and the oil up to temperature. We only see 3 bar at start up, from cold iron. This car has an oil pressure and oil temperature gage set, so we can monitor them both. The fix is to replace the oil pump, and on this car, that easier said than done. Jim

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Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

On most cars the sendor just fatigues with age and use. It is the weakest link in the system. But you have to find out. They should be cheap or it might be faster to grab one off a wreck. The used one should be ok. But if the same identical results are present with it just do not drive the car until you find the true cause.

I have tried a hand held gauge and I have more pressure than you can shake a stick at!
So the sending unit is faulty...But what a scare!
Thanks again folks for your wisdom...
Best regards to all
Dan
Vancouver Canada

Just a foot note ....
I did get to changing my oil sending unit today while performing an oil change,and that oil pressure is back up to normal.
Regards
Dan Vancouver BC

Yup, really amazed that anyone would post a querry for help on a forum like this not not have the sense to list the make and model of the car. Yup, really amazed!

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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!

It still isn't in his signature, but you might want to reference post #9 and get back to us.....




Post #9

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Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John

If you would had read the first few posts,you would have noticed the type of Benz I was refering to! And you would not have been so Amazed! my friend!!

I think what is amazing is how easy it is to put in a signature file that lists things like vehicle types and how crazy we are, and also how many out here on this forum fail to do it.
John

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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!