There have been some issues on the MG forum about this very same thing - persistant leaks with alloy rads, which can't be easily repaired.
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I was wondering whether anyone can answer this question although it is not applicable to my MGRV8.
I also own a Rover 75 year 2000 which we use in the winter becasue of its superb traction in the snow.
Anyway we discovered a water leak coming from its Radiator. Bosch tell me that modern alu. radiators cannot be readily repaired at reasonable cost and that a new one is the sensible answer.
Don't mention aluminium radiators to me - my blood pressure will go through the roof! I bought a very expensive aluminium radiator for my MGB V8. From the very beginning it leaked, just a little bit, where the vertical tubes enter the bottom tank. The supplier took it back for repair and sent it back. It still leaked.
The supplier took it back and re-cored it. It still leaked. As it was now three years since I bought the thing, they agreed as a final offer to make me a brand new one. It leaked just the same as the original one did.
I took it to a reputable radiator shop in Glasgow and he was very rude about aluminium radiators. He said they are no more efficient than a copper and brass one, and they are almost impossible to repair. He sealed around the tubes with an epoxy resin but he said it was unlikely to last and he was right. Three months later the leak was back just as before. So I suspect you have been told the truth.
