Not a silly question at all. At first I noticed a "puff" of what looked like steam comming out from under the bonnet. I put some "radweld" in the radiator to see if it would fix the leak. I left the car running for half an hour as directed by the "radweld" and it did seal the leak.
It was only when I drive the car that it started to leak again. I guess it was the additional pressure build up from the system. The leak is right at the top of the radiator in the middle. I am not an expert but I am not aware of any hoses running through this location?
I will try and do some more investigative work and possibly remove the radiator at the weekend to identify exactly where the leak is before I go and purchase a new radiator. In a way I am sort of hoping that it is a leak from something else like a fitting or a pipe as this will be easier to rectify.
E61 2.0D Auto
Last edited by white_lancer; 11-20-2012 at 05:02 AM.