My 1998 Ford Taurus LX did this and it was just low on engine coolant. My aunts 2001 Nissan Altima SE sedan did the same thing and it was also low on coolant. I thought that was quite strange for a 2001 car, with 28K miles.
1993 Mercedes 400SEL 4dr
2012 Honda Civic LX 4dr
1972 Chevrolet Caprice Kingswood Estate 9-passenger wagon
1973 Pontiac Grand Ville 4-dr hardtop sedan
1988 Mercedes 300SEL (was mine, now mothers)