freelander 1 intercooler

Hi everyone.I am new to all this so would appreciate some advice.Can anybody tell me if i can clean my intercooler out while its still on the car or do i have to get it off to flush it out?Ive done most of the mods ive read about but still have oil in the intercooler pipes.Have no lack of performance so would like to clean out the whole system before i go down the route of new turbo.Is there any way i can check the turbo while its still on the car-cant even see it from under the bonnet.Be glad of any advice because i love the freelander,bought it new on a 56 plate and its imaculate so would like to keep it many more years.Serviced regular but it think main dealer didnt change crankcase filter,ive changed it twice though and just ordere BMW mod,just hope its not to late for the turbo.

flush it thru with petrol usually 1 gallon will do fill the intercooler with petrol,take turbo pipe off and look down the pipe using a ciggarette lighter this should show up any blockages