Yes, sounds like crankshaft position sensor. If the problem is the same as with my 2000 C280, your next symptom will be SSS, sudden stall syndrome where your car will just randomly turn off. Check with the dealer for the cost of the repair, then go to Fastlane and buy the part. You'll need a tool not in your average garage, IIRC an E8 torx socket, DIY and figure all the money you saved!

glenmore
1991 300CE
2000 C280
1990 LS400