I get the same thing on my TDV8 RRS, but only in really warm conditions. I run with the aircon almost 365 days of the year, but it seems that when the ambient temperature is above 30C, the compressor goes into overdrive immediately after starting the car. The revs die down again after about 20 secs and then all is good in the world again (although it does sound good when the TDV8 revs :twisted:)

