Intermittent Engine Revving At Start Up

[neil the courier]

Hi folks I'm new here so please forgive me if I am covering old ground! Sometimes when I start my galaxy tdi the engine revs up higher than normal and throws out a cloud of black smoke. This coincides with the temperature gauge dropping to zero. It then drives fine but with a higher tickover. When the temperature gauge returns to normal, the tickover drops back down and the start up doesn't result in over revving and smoke cloud.

I would appreciate any thoughts on this. Cheers.

[GreenSharanTdi]

Could be a faulty temp sensor confusing the system

[traff]

classic temp sensor fault ...replace ...problem gone