> A4 2.8 1996 - 46,000Km
>
> Coolant is slowly decreasing. About 1 month from max to min.
> No leaks, smokes or smells.
> Temperature - oil & coolant - Ok.
>
> Curiously, when I topped the coolant to Max I noticed a few hours
> later some coolant in the floor. (engine cold - not turned on in any
> moment)
>
> Can it be just a minimum fracture in the higher part of the reservoir
> or should I be looking at somethng else?
> I imagine that the coolant works under pressure - cannot understand
> leaking with the engine cold and no pressure at all.
> BTW: after the mentioned leak - no more than 12 hours later - no leaks
> at all. (and reservoir at MAX level)
> Thanks in advance for your help.
> Jorge

I think you could use a UV lamp to detect small traces of coolant. On
alt.lasers, they had a discussion some time ago about using UV LEDs
for that purpose. Apperently, it works quite well and the UV LED
shouldn't be expensive. You might have to clean your engine first,
since they said those thing detect extremely small quantities.

I also saw somewhere mentioned that you could fit a tyre valve (e.g.
from a bycicle tube) to the cap of the reservoir (best get a spare cap
for this) and then pump it up to some pressure to detect leaks.

Good luck,

Christoph

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