revving up and down on startup

[fatfighter]

hello,i have owned my audi a4 1.9tdi se avant for 3 weeks now, on two occasions when i turn the key the car seems to "rev up and down" but then returns to normal tickover,it only happens for about 5 seconds but is really noticable,the first time it happened was when i had the car for about a week,then it happened yesterday,the car runs fine and fuel consumption is really good,any ideas?thanks in advance. p.s the car just doesnt rev up a little bit,but quite a lot and then back down and up then down and then to norm.:1zhelp:

[Col]

You need to get the car read for faults. Look in the vag-com sub-forum for someone who may be able to help.

There are a multitude of sensors on the engine and any one of them or combination of them could be causing the problem.

To hazard a guess though either,

water temp sensor
or
cam position sensor
or
needle lift sensor

[fatfighter]

thanks a lot for the reply,will get the car read by some audi software,cheers!:approve: