Just a quick one if the majority of my intercooler fins are bent and damaged could this effect my cars performance quite badly and could it cause a boost leak? also can a dump valve cause a boost leak??

 

If most of the fins are bent down, this will reduce the amount of air passing through the intercooler, meaning it does not work to its full potential.

What year car do you have? Some more details usually helps, as classic intercoolers have a tendency to crack, and can produce boost leak... dump valves can also produce boost leak (depending on what dv you have fitted - yet more details required)

 

most of them are bent and my car is 1995 and the dump valve is a blitz dump valve ???

 

For the sake of 15-30 quid, get yourself a better replacement (small 'slanty') one... Loads on eBay:-

subaru intercooler