这个老白也还算熟悉,3 z% Y; q; n. t, [" [* P
1. low coolant level1 L9 D) Q0 s% G4 v9 b4 l S8 f/ Y3 v: o
2. thermostat is stuck open" @3 F! I3 [ [ L6 j) B. m/ e
3. fan motor does not run well2 \" R, Q* f- V8 F' H
4. heater contorl valve blocked- Q: |! G o% O, _$ P
etc