Check that the wire connected to the sensor is not loose. Cost $0 about 5min. Labor.

Also, check the engine-chassis ground strap if there is fluctuation.

__________________
Sam

84 300SD 350K+ miles ( Blue Belle )

i believe the book says down to 1/2 bar is ok.

i am betting on the sensor or wire too.

if it actually had zero pressure you would be seeing other problems like noise.
imho.

but dont fool around, fix it. true zero oil pressure is the kiss of death for an engine.

tom w

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

I'll give that a try, but where is the sensor?

On the back of the oil filter housing.

__________________
Sam

84 300SD 350K+ miles ( Blue Belle )

Would suggest connecting an aftermarket (mechanical) gauge...If symptoms confirmed, Shut Down immediately!

Yep lets here it for the new guy!

First confirm with mechanical guage, then take it from there.

__________________
2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200

I'm going to make the assumption that you did not pull the vehicle over to the side of the road when the pressure dropped below .5........correct?

And, you probably drove it at 60 mph for several miles with the gauge on "0".

If this is the situation, and the engine is still running, then you have successfully diagnosed your problem. Change the oil pressure sending unit and the problem will be cured.

If, however, none of the above occurred, then more analysis is needed to determine why you have low pressure on the guage.

Also if the oil pressure is really 0 you should hear it. Even with a 617. I know on a 603 the lifters would be going nuts!

__________________
2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200

The lifters and the upper end of a 603 starts to really offer a racket with full oil pressure on the gauge (3.0) and the oil level at three quarts below the full mark.

The logic of this escapes me, but, clearly, the gauge reading is not the oil pressure in the head.

Ever pull the oil cap and see if you are getting oil up there when its that low? The oil pressure guage must not be the most accurite.

__________________
2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200

I don't need to pull the cap........I can hear it clearly.........there's not enough oil in the head at that point.

The gauge is accurate for the point where it's sensing the pressure, however, the pressure in the head must be significantly less.

There is a wire right around the bottom of the transmission that just hangs there. Is this the chasis ground you are talking about? And if it's not attached will it cause the oil pressure sensor not to work properly?

O??? My vote if the car was running at that supposed pressure and not making any racket is the sensor. As has been said before open the oil cap when the gauge reads o and see if oil is flying about or just hook up a mechanical guage and see what it reads.

__________________
1981 300D 147k
1998 VW Jetta Tdi 320k
2001 Dodge Ram 2500 141k
1979 300D 234k (sold)
1984 300D "Astor" 262k(sold)
Mercedes How-To and Repair Pictorials
I love the smell of diesel smoke in my hair

As the title reads quite a bit of oil spurted out when i took off the cap at 0 oil pressure. I imagine this confirms that my sensor or wireing is shot.Thanks for all the responces.I'd be out a fine cent if it wasn't for all the advise i've gotten here on this site.Thanks everyone.your the ****.That last comment is good if some of you don't know btw.Dam censors.

Changed the sensor today and now I have 2 bar.Whew.not too bad for 300,000 miles. Btw did anyone see the 4.6 million mile 76 240D that mercedes has in their museum? Quite impressive! Lucky ****er got a new 200 cdi in exchange for it.