For the longest time, the tach on my 300sd has simply just not worked. I've read the threads on tweaking the tach amplifier and such. My tachometer has begun to work sporadically without even touching anything to do with the tach at all. It will go to 4000k under hard accellleration while shifting and then drop down to zero. Sometimes it will hover between 500k and 1500k while cruising. It obviously isn't very accurate. I'm not really interested in fixing the tach immediately, I was just wondering if anyone els has experienced this with their cars.

Thanks