golf overheating

[jacra1721]

i have a 2003 1.8t 180bhp that overheats when the turbo is on boost ! on idle ,in traffic ,and under normal driving its ok . the temp sender unit has been changed as i'd heard that was a common fault with vw's !!!! it does not lose any coolant , the top rad hose is hot the bottom one is cooler as usual , the coolant has been checked and was found to have hydrocarbons in it any ideas ???

[simonruss]

any problems with the turbo venting off?