Would replace the stat too, sounds like it is stuck "open" possibly from having some unwanted junk in the system. Mine did athat and ran at 160-180 degrees(too cool) The stat should be where the top radiator hose connects to the block. Remove the two bolts and pull the hose and metal cover off. Clean the area and replace. Pick up a Haynes manual for 12-15 bucks at Advance to guide you through it. Not a hard procedure. The only problem is what to do with the used anti freeze. In our area we have no way to dispose of used anti freeze without paying someone to take it.