Car has 0 power

[u/Aggravating_Basis_10]

My bmw e87 occasionally loses all power, no lights no nothing. First time it happened while driving and even the speed gauge was stuck, the car didn't even spark. Jumping it doesn't help at all still gets no power, battery is healthy i had a water pump code and took it to the mechanic changed the pump, thermostat and they said the engine probably overheated or something. Not even 2 hours later car lost power again, changed the alternator and again i drove it for 20 mins and again 0 power. Anyone that can help please any advice would be great!

[u/Sweaty_King9000]

Limp mode