right upon mild acceleration my turbo whistles then when i put my foot down it makes a hissing sound as if the boost escaping. then it loses power and is flat but will drive but takes longer to change up the gears and rev normal??
Check outlet hose from turbo you will need to raise front end then remove undercover to do this and while under there check intercooler hoses for splits/perishing.
right no splits and clips all tight the inter cooler looks fine, I have taken the air intake off and no play in the turbo!! ( the turbo was replaced this year) its all shinny not tarnished so i think this is true??
Could the cat fail and restrict the boost pressure when high?
You need to get it read for the fault code (the lack of power suggests its gone into limp home mode). You need to know if its an over or under boost issue.
it resets it self when i turn it off then start it?
Yup, that's going into LHM. Read the ECU memory for faults and you'll have either an over or under boost issue.
and is the cure exspensive??
Went to the garage today and had it on the diagnostics and the turbo is fine (should hope so its a brand new unit no even 6 months old), Monday hes going to smoke /pressure test all the system to find the leak!!!
all fixed just a failed intercooler pipe!!
Was it the turbo outlet pipe as I suggested? part number would be useful for future reference or pic.