Anybody tell me why when I first start the car up from cold it revs to about 1500-2000 rpm?, it only stays at these levels for a couple of seconds. I don't touch the accelerator at all but it still does it, once the car is warm it will just start normaly. This doesn't always happen but mostly it does!, I'm also worried about the damage that could be being done when it revs like this straight from startup with little or no oil circulation, as there is usually a little tingle of sound just as it fires up, kinda like the old tappet noise, is this perhaps the hydraulic tappets pumping up from cold?