Ive had a new Cat on mine (under warrenty) as the blow sounds like it was coming from there, but it still makes the noise, so assume its normal. The first place I took it to told me it was induction noise!!! As for the suspension, mine isnt so much crashy (probably cause its got the stiffer setup), but mine groans when I pull away and the steering is heavy whilst it groans. Once if pulled away and the suspension settles, its fine for the rest of the journey. Dealer cant find any problems. Has replaced several parts but to no avail. It didnt do it when I bought it, it just started, thats the wierd thing. As I say, the steering goes heavy whilst the noise is occuring, I dont know whether its a suspension or steering issue. It only occurs of first pull away, as the nose rises. Other than that, nothing is affected during normal running. Wierd!!!