my new wrx is great, but ever since I have had it (10 days & 700 miles) it has had a slight shake when Idling. its weird one second its smooth then there is a slight shudder through the car then smooth again, it seems to do it every other second, just like when the revs drop a little too low, but I have noticed it do it at 1500 revs when it first starts idling.

When I had first got it I just put it down to dealer putting 95ron fuel in, but it has had two tanks of optimax now and it still does it.

I thought it was a problem with it idling, but it seems to sit at a constant 600-700 rpm at idle once warm and doesn't wonder.

I have been driving it under 4000 rpm (except for the occasional blip) but like I said it has done it from new.

It hasn't had its first oil change yet, and its getting ppp'd at the same time, but is this something to be worried about, or will the first service sort it.

 

My week old wrx is exactly the same and also idling at 600 or so rpm

 

Thanks for the reply,

That makes me feel a bit better, hopefully its normal, but it had got me a little worried.

 

Mine do'es it sometime's (my03), turn the air con on it'll be even worse! Or have you left the air con on all the time?

 

thought about the aircon, I have tried it with the aircon off and it still does it, but not quite as noticeably.

 

They all do it, I guess flat fours aren't the smoothest engines in the world