Can anyone help, my MY99 with 43,000 miles has developed an odd wirring or wurring noise from the engine after it's been revved quite hard during a blast. Once the car has slowed to traffic/potter speed, the wurring noise is quite distinctive and rises and falls with the engine revs. After 3 or 4 mins the noise is gone. The power steering makes a similar noise when on full lock - are the two related? I also get the tickover knock that Otis was talking about, but it's done it from virtually new.

 

The powersteering is probably the relief valve opening on full lock.
The other ticking could be anything from a belt, to lifters etc..

Best to get it checked while under warrantee.