Quote Originally Posted by llandro View Post
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But what does arouse my concern is that I noticed after the first timing belt change (prolonged bleeding of the cooling system, bah!) that when the engine was revved to around 1500 a string of bubbles appear in the header tank.
They dont ever get more, never less, the tank has no more than a normal hiss if I take the cap off when hot.
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llandro
Normal.

It concerned me after a belt change, exhaust gas tested the coolant innumerable times (OK, about 6 ) and always negative.
Travelled 72,000km since.