[Christien]

Technical, but non Porsche-related. Last night I noticed the temperature gauge in our 2005 Honda Odyssey was at full, after about 15 minutes of highway driving. I immediately pulled over and stopped and let the engine cool down. I didn't notice any signs of a leak, and I put 2 L of tap water in there. I continued driving for another 2 hours at highway speeds, and the temperature gauge read normal the entire way, even with the a/c on.

Not knowing anything about coolant (I've only done serious wrenching on 911s), how urgent is it that I flush the water and replace with proper coolant? Doing some Google research while waiting for the engine to cool down, I learned that it's not uncommon for cars to have a slow leak of coolant over time that doesn't really need to be repaired, just topped up. The van has 177k km, and judging by other maintenance items I found (or lack thereof) when we bought it at 125k, it wouldn't surprise me if the coolant system had never been addressed. So I don't think we have any imminent failure of either hoses or the water pump. But from what I understand, I can't just leave the water in there permanently.