The oil level in my '95 E300 Diesel, is 3/4 up on the dipstick (as measured overnight on level ground).

Occasionally while driving, the oil light would come on, yet the oil pressure gauge pegs at full pressure, and never drops below 1.5 while hot and idling. This can happen at any speed, and does not matter whether I am going up, or down a hill, or whether I am driving straight or making a turn. The engine runs fine otherwise. No unusual noises. No smoke. No leaks. No nothing.

Do I trust my oil light, or my oil gauge? Any ideas why the oil light comes on?


Thanks

Phil

The dipstick only measures the top quart or so of oil, so you would not even see any on the dipstick if you were seriously low. The light will come on intermittenly when it thinks you are getting a little low (reference your manual for details regarding this engine), maybe a quart or so.

Also, there is a 60 second delay built into the sensor so the light will not come on when you take a long, high speed curve.

Sorry I can't give you a definite answer, but someone will

__________________
'90 300SE 298k
-300K and it gets put into retirement.
'80 300D 255k Purchased new by family in 1980.

Had a:
1973 220 (gas)
1980 300SD
1992 400E

The oil level sensor to the light has a checkered history as far as reliability, so statistically that would be the culprit, given the fact that visual inspection confirms correct oil level.

__________________
The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)

I think both of you are right, and that it is my oil level sensor. Its seems to be very sensitive, and indicates that I am low on oil even though my dipstick is showing 3/4 full.

I topped up my oil to just below the Maximum mark on the dipstick and now the oil light seems to be happy.

Thanks for you feed back.

Phil