Couple Of Issues With My Focus

[dahardy58]

Hi there a few weeks ago my 2007 ford focus zetec 1,6 started making a slight grinding type noise. it is now more frequent. it tents to occur more at lower speeds. brakes still seem to stop me as usuall. It sound like it comes from the rear of the car and nothing can be felt through the Teering wheel.

second issue is when car is sat ideling there is a slight dip in the engine noise. its like the revs slightly drop. this only lasts for a second or 2. it has never cut out but still seems not right.

any ideas at what i am looking at and rough idea of cost i could be looking at