I had this problem ,it was the top sus mount bearing,I just bought the entire strut on ebay for £40,as the spriing is not very safe to compress,watch out for the sway bar nut as it has a torx bolt on it and it has a 18 mm nylon locking nut u may have to burn off as i found out.You can buy a new sway bar on ebay with the nuts for around £20.Thank god for ebay