这个老白也还算熟悉,; I: s# ?( k6 E, ?; z$ A% F
1. low coolant level. S' y% A1 k' G+ y6 C% Z
2. thermostat is stuck open4 G6 n7 W1 ?2 d9 I# N. ]( v3 Y
3. fan motor does not run well * k; Y( T, Y* }8 T2 z! W8 k0 e6 u! ]4. heater contorl valve blocked # L w( c! N! u' vetc