What's the stock thermostat for a 1987 Volvo 240DL? I see multiple temps, though since our car is older, I may need to go with a lower temp, and I live in Southern California.

Also, what's the best way to drain the coolant to perform this job?

http://www.ipdusa.com/Volvo-200/Heating-&-.../p-69-261-1261/

I'd go with the 88C unit. There is a drain plug on the block somewhere but I'd just remove the lower hose and stick it in a catch pan, and remove the upper hose for a vent. Consider replacing the hoses if the are old. Take the coolant to the proper waste collection center.

I agree with robert240, there is a drain plug but I’ve never used it, the thermostat opening temperatures are dependant on the engine size and type could you give me more info. Of course you can select a different thermostat if you live in a particularly cold or hot area.

I'm having doubts as to it being the thermostat, as if she downshifts and makes the engine work harder, it cools it down, like as if the water pump spinning faster makesi t cool down better, which may just be it, the water pump impeller.

or does that still sound like the thermostat?