hi, my jazz leaking coolant from reservoir tank, engine temperature hot, already replace thermostat, radiator cap, and water pump.... the odd thing is when drive downhill temperatur become normal..... any idea?

 

Your engine is under less load when going downhill, so that may be why the temperature decreases when going downhill.

There's any number of reasons why the car could be overheating. The most common is probably the thermostat.

You said you replaced it, but with what brand? Honda or aftermarket? Aftermarket ones can sometimes cause problems because they don't always meet the necessary specifications...

 

thermostat orignal honda

 

did you put it in backwards?

 

we install in correct position, same position from the old one.