E60 Engine Overheat - Drive moderately

[Shiran]

Hi All

My car is 525i e60 2007
I recently changed the upper radiator hose. After 2 weeks of changing it, an error message came up as “Engine overheat - Drive moderately”. Once I have this message I have to stop the engine and start after couple of minutes. Error message comes in like every 20 minutes drive.

Mechanic said:
-Water pump is working fine (after checking)
-There is a coolant leak from the radiator ( which was there for a long time even before this error)
- coolant level message is not coming

After that he changed the drive belt and tensioner saying that the battery is not properly charging due to skipping of the belt. Also changed the radiator cap saying that cap is faulty.

Car ran well for one MONTH without an error after these fixes, but it came again.

-Coolant fan is working fine


What would be the problem and solution.

Thank you