thermostats OPEN at 88.cooling systems are pressurised,so boiling point of coolant is not 100 but closer to 114 dgr,so provided the fan cycling correctly i'd be happy with temp.max engine efficiency is when hot.make sure anti freeze is at correct strength and monitor temp.ps gagues are seldom accurate.indipendant temp test will check,but only if system is still pressurised.if still worried try flushing it.
caine, August 2008
