Thank you to all and particularly Spook for the very clear and helpful explanation of how to remove the engine temp sensor. The warm day I was waiting for finally came this weekend (Boston). I was able to locate the sensor and with minor difficulty remove it without moving any other component. On my 1995 940 Turbo it was accessible with a 17 mm open end wrench - just barely. My wrench was a rather short length as it came out of my BMW OEM tool kit, so I would recommend something a little more like 12 to 14 inches so you have some leverage. The sensor comes out easily because its brass in the iron.

I called my local Volvo dealer and they had the replacement for $66. I purchased one on line for $14 and $5 shipping. It should arrive this week and I'll update on the success I am anticipating.

Bob Franklin