Hi jfh,

Thanks for all the information. I will check out the info about the comp board, but I plan to drop it off Sunday to have the Volvo mechanic look at it (it's a shop that works mostly on Volvo, and they've worked on it before). The thermostat that was replaced was purchased at Auto Zone, and I don't have a clue if it's the correct one.

Gotta say I was so excited to finally see that gauge at the midway point, yet only a few miles later to be so disappointed. I also thought the post about the "solve" with the antifoam might help others. Who knows, though, maybe it will.

I will post again after I hear what the shop has to say. I'll write them a detailed note about the problem. I was told that a gauge replacement would cost about $100, and I'm not sure if that's a good price or not. It just might be a combination of a gunked-up radiator and a bad gauge.

Thanks again!

Susan