There is a fix for a fluttering or trembling (as M-B calls it) oil gauge needle. Install part no. 123 542 00 74 into the oil pressure line at the gauge with the tip end going in first (see, M-B engine manual pg. 18.4 - 005/8). What this means is that a trembling oil gauge needle is normal and nothing is wrong. My needle would tremble at an idle after a run on the highway with 10W-40 oil (for winter driving, about 2 hours long in S. Tex.). I would switch to 20W-50 for the 11.999999 months of summer we have and the needle would not tremble. I now use 15W-40 Chevron Delo 400 oil and the needle does not tremble.

Good Luck!
Tom

__________________
America: Land of the Free!

1977 300D: 300,000+ miles

American Honda: Factory Trained Technician & Honor Grad.
Formerly:
Shop Foreman;
Technical Advisor to Am. Honda;
Supervisor of Maintenance largest tree care co. in US for offices in Tex.