It is unusual for the oil pump to go. I would try to verify that it really is a pressure problem. These cars have an electrical transducer to convert oil pressure to a proportional voltage output. You can replace the transducer. Mine cost $57 (part only). If you are mechanically inclined and can get ahold of a mechanical oil pressure gauge, then put a fitting where the transducer is and verify the pressure with the mechanical gauge. Otherwise have a shop verify it.

Meanwhile, while driving the car, don't let the pressure get below .5 to .7 bar. I kept one foot on the brake and one on the throttle and always added enough gas to keep the oil pressure up. I drove like this for about 6 months before the timing chain broke and I was forced to take everything apart. (the two were not related, the chain had 218k miles on it)

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)

Just curious. What was the outcome of your low oil pressure problem? I am having similar concerns. thanks Bill

SUBJECT
GROUP 18 - ENGINE M119 - w140

Is there a ticking noise from the valve area and/or low oil pressure, the cause could be a missing plug in the oil feed tube (part no. 119 180 02 66) between the camshafts. If one of these plugs is missing, the oil pressure to the valve elements / chain tensioner will drop causing this complaint.

The complaint can be repaired by exchanging the leaking oil pipe and checking if all other plugs are tight. The loose plug can usually be found in the valve area or in the oil pan, and should be removed.

After the repair, start the engine and check the oil pressure. The oil pressure must be within specifications (< approx. 6 Bar). Oil pressure which is too high can be the result of a faulty oil pressure relief valve (See Diagnostic Directory 18-121) which in turn can cause these plugs to be pushed out.

I use Mobil 1 0W-40 in my 300TE.
Wal-Mart and AutoZone carry it in this area. $4.77 a quart at WalMart, a few cents more at AutoZone.
My oil pressure has been dropping to 0 (right to the peg) since switching to synthetic.
This bottom end stuff is scary ... right now I'm fixing up my SD.

__________________
Bob Roe
Lehigh Valley PA USA
1973 Olds 88, 1972 MB 280SE, 1978 Datsun 280Z, 1971 Ford T-Bird, 1972 Olds 88, 1983 Nissan Sentra, 1985 Sentra, 1973 230.6, 1990 Acura Integra, 1991 Volvo 940GLE wagon, 1983 300SD, 1984 300SD, 1995 Subaru Legacy L wagon, 2002 Mountaineer, 1991 300TE wagon, 2008 Murano, 2007 R320CDI 4Matic 52K, some Hyundai, 2008 BMW 535xi wagon, all gone... currently
2007 Honda Odyssey Touring, 2014 E350 4matic

Before you do any major thing or even speculate major problems, do, as I should of done.

I replaced the oil tubes, about an $1800 job at the dealer only to find out that what I needed was an $80 oil pressure sender. It took me under 10 minutes to replace the old one. Mine attaches to the bottom of the oil filter housing.

If you are not experiencing any loss of power, I would start there.

The dealer recommended the Oil tube Job, not anyone on this site. People on this site actualy recommended the pressure sender. But I was too foolish to listen. I thought the dealer knows what they were doing, and they did, which was screwing me over. But I did the Oil tube stuff my self, so it ran me about 1/4 of that in parts.

Good luck.

__________________
1993 400SEL (W140) 281K
1999 S500 (W140) 163K (Sold)
2002 S500 (W220) 72K
1999 S500 (W140) 88K
You cannot simultaneously prevent and prepare for war.
Albert Einstein (1879 - 1955)

Power is good; although I do get a bit of lumpiness or rough idle sometimes.
I hear something going "tick tick tick" when I start it cold, but it goes away in about a second or so.
I want my oil pressure guage to read right, so I will very likely have my mechanic replace the sender.
He drove my car and didn't seem too concerned about it, but seeing zero oil pressure is not what I want to see.
Too bad I just had the oil changed ... I was running 15W50 M1 which didn't drop to zero quite as fast.
I assume the oil has to be drained in order to change the sender?
I have to rev the engine up to about 1500 rpm at idle to get the needle to budge from the peg.
I assume/hope that I don't really have "zero" oil pressure, or else I would have fried the engine months ago.
However, I don't want my car to be like one of those engines in the synthetic oil commercial where they drain the oil and run it for hours and it still runs... was that Castol Syntec?

__________________
Bob Roe
Lehigh Valley PA USA
1973 Olds 88, 1972 MB 280SE, 1978 Datsun 280Z, 1971 Ford T-Bird, 1972 Olds 88, 1983 Nissan Sentra, 1985 Sentra, 1973 230.6, 1990 Acura Integra, 1991 Volvo 940GLE wagon, 1983 300SD, 1984 300SD, 1995 Subaru Legacy L wagon, 2002 Mountaineer, 1991 300TE wagon, 2008 Murano, 2007 R320CDI 4Matic 52K, some Hyundai, 2008 BMW 535xi wagon, all gone... currently
2007 Honda Odyssey Touring, 2014 E350 4matic

I am not eh expert to say, but I believe the tick, tick is normal for initial starts since the oil is on the bottom or the pan. The oil did not have to be drained on mine, so I doubt it will need to be drained on yours, you can change the filter with out draining the oils since the filter housing sits higher than the pan and not on the bottom of it like most cars. The fact that you did not fried the engine or lost power tells you that your pressure is actually/probably good it is the sender or the gage. So in other words the delivery of what is actually the pressure is what you seem to have at fault here. I am not sure about that commercial and I am not daring enough to try that with my baby. I run synthetic in mine.

__________________
1993 400SEL (W140) 281K
1999 S500 (W140) 163K (Sold)
2002 S500 (W220) 72K
1999 S500 (W140) 88K
You cannot simultaneously prevent and prepare for war.
Albert Einstein (1879 - 1955)

Dear All,
I have similar problem like Pilot 2000
My 91-300E ( 156Km) measures 3 bar at starting up with idel at 1500rpm

As soon as it warms up to 80deg C. The oil pressure fluctuates with the rpm. It drops to zero when it idles ( 700 rpm). It jumps quickly to 3 bars on acceleration above 1200 rpm.

The Zero Oil pressure is measured with a mechanical gauge outside the engine block.

The car had been like that for the last two years.

two days ago, my mechanics installed a new oil pump and a new timing belt tensioner. but the problem is the same

The oil is changed regularly ( 3km) at the dealership
My mechanics gave up and is recommending buying a used engine or open the engine to check.

Any helpful ideas Please