Hi again,Any update?
Thanks for the reply and I'll do as you say as i will get a cooling flush and try that and see if any remnants of oil show themselves..Glad things are a lot better with the flushing.. Why are you changing the radiator? Is the car on the road yet? I would use it with correct coolant for a couple of weeks as is then reassess it after that. If still a little oily use a commercial radiator flush for aluminium and again replace the coolant afterwards. If it was accidental or deliberate oil in the expansion tank that should get the last of it out. In the warmer temperatures obviously the Webassto does not fire up but the coolant still flows through it the same way the coolant flows through the heater matrix. When you have time keep us updated as lots of members are watching this and hoping for this "cheap" remedy to clear the problem.