Oil pressure guage.
I have a 1990 500SL with 74000 miles. The car is in excellent condition inside/out. The only problem is: While excellerating, the oil pressure guage will sometimes bottom-out and the red, warning light will come on. As soon as I take my foot of of the gas, the guage will go back up. I did listen for lifter and valve noises, but I can't hear anything. The oil level is fine. Any help would be appreciated.