My oil light came on while driving home this evening. This has happened before. Each time it comes on, it stays on for a minute or less (doesn't blink) and goes out. The oil pressure does not go down but remains at 3--as it should be when the car is in motion--when the light comes on. When I check the oil level, the oil reads either just below the midpoint or .25" above the red LOW mark. I should point out that I check it a few minutes after I pull to a stop, so the reading should be a little higher when all the oil has settled down. Usually I check the level again in the morning when the engine is cold and has settled down. The level then reads either at the midpoint or a little above it.

How low does the oil level go on the dipstick before the sensor comes on? I drove my car home for another 10 miles in stop-and-go traffic when my oil light came on because from experience, my oil level usually isn't on or below the red LOW mark when the oil light comes on (and doesn't stay on). And the oil pressure was high. Am I fine? Is this a sensor thing or a low oil issue? Car is a '90 190E. Thanks.

I have a similar problem... only it's the opposite.
My oil level light won't come unless there's almost NO oil in there. I know it works because when I change my oil, and if I turn the key to position 2, the oil light does come on. But one time I checked my oil, it barely even touched the dipstick! And no oil light.
I think maybe the sensors just get dirty? Or mis-aligned?

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2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)

The important thing is oil pressure. You are doing the right thing by keeping a close eye on oil pressure when the oil level light comes on. Just top it up, when the light comes on, and you'll be in good shape.

Good luck,

On almost MB after 1985 the oil level lamp should come on IF the oil level is 1.5 liters low for 45 (continuous) seconds of engine running. MOST people would not let the level get that low.
BTW MB cars starting with the C-class in 1994 no longer have oil pressure gauges!!!

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MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Some MB "purists" won't like this but, I used an engine flush and I changed my oil. Problem solved. Dirty sensor? Who knows...but, it worked for me.

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J.H.
'86 300E