I had to drive about 10min with the low coolant light on (city traffic). During that time, the engine temp gauge stayed at 1/2 and did not rise.
I think it was a coolant leak at pressure, I saw steam coming out on the passenger side, and it smelled like coolant. The next morning I poured about 1.5L of G13 in the expansion tank and the level remained steady while the engine is off.
Today, I finally had a chance to take it to the nearest garage (Courbevoie outside of Paris). The engine seemed to emit steam after 2m–before the temp gauge even reached 1/4. It was coming from below cyl2/3, from the gap by the passenger air filter.
I was hoping that the leak was from a hose or clamp that popped loose from heavy, cobblestone-induced vibration (an ill-advised Eiffel Tower joyride). But the (non-Audi) garage mechanic said they spent 3h searching for the leak and couldn’t find it.
Now it seems to me a pressurized coolant leak should be easy to find, right? But they said it seemed to be engine exhaust, not coolant. (Of course, I don’t speak French, and my friend translating doesn’t speak car.)
Is there any way that I could have warped an engine block/seal/gasket by driving it on low coolant when the engine temp gauge does not move? Am I DOA, or should I find an Audi mechanic who speaks English?
(There is so much more to this crazy story, but I’ll leave it for another time. However, this is a real pain cause I’m 300km from home and there is nowhere to park a disabled car in Paris…)