这个老白也还算熟悉, ' ]- x% m! j6 w W, i1. low coolant level# n. k& v& A A8 s- U/ B
2. thermostat is stuck open : u* J' D! M% y: X1 U3 a) O7 H3. fan motor does not run well8 l% S4 _- q; H$ a0 _& e2 N( x
4. heater contorl valve blocked7 c6 i* x# c' c# m2 l5 ]& ^
etc