this sounds like the self adjusting tappets that i have in mine,they will make a noise for about 5 mins until they have set themselves,this is quite normal and should be expected.with regards to the info centre it sounds like a duff,although some of the displays wont actually appear unless you are moving.i don't know about the heat/cooler system but i would imagine you will find something on here using the search facility,the sparkplugs must be the genuine volvo ones for your engine(t4's are very fussy!)hope this of some help,mike