Coolant Leak - Running Out of Ideas

[JFP in PA]

Originally Posted by blue2000s

If you open the bleed valve and let the car run, or drive around for more than 15 minutes, it gets circulated throughout the car.

You're right, without the bleed valve, it does just sit in the tank.

Actually, it will circulate if added to the tank; you might need to run it for a day or so to get full effect, but we have seen it disperse in as little as 30-45 min.

[blue2000s]

It took a long time but I finally found that the coolant is leaking out of the expansion valve at the top of the reservoir. It seems that it very rarely leaks since I've lost no coolant in a couple of months, but yesterday the blacklight showed drips around the valve and at the top of the trunk lid.

My valve is original so it doesn't have the o-ring, so I'll order a new one and hopefully the mystery is over.