Hello forum members:

The tachometer on my 740gle has begun acting weird with the onset of the cold weather. Everytime I start from cold (say in the morning or after more than a few hours), it stays at 0 with engine running somewhat rough, but not much. About 10-15 minutes into the trip (when the engine reaches normal operating temp) it starts to rise slowly to the correct rpm. Thereafter, the engine runs smooth and fine. I have notice also that sometimes when starting the car from cold, the needle goes straight to 2000 and stays fixed there until the engine has reached operating temp. What could cause such a behavior and what needs to be changed? Thanks in advance for your responses.

Yona