S55 engine quickly gies to 120c when air con on.

[rooferboy1959]

This has just come out of mercedes two different indies, let's start from beginning with this, new radiator new condensers air con all done, radiator was done at njs solutions, air con is like like warm , temperature is holding in this hot weather at around 90c, air con is ****, then all of a sudden temperature will spike in say 10 seconds to 120c, no sign of immediate overheating, can be a loss of power. Was in keys at Bexleyheath last week for some routine maintenance and they ran a test no fault codes, did it today when temperature spiked quickly on my vode reader no faults, have done the bleeding bit , still happening. Completely baffled, any insight would be welcome

 

[alexanderfoti]

Must be sensor fault, it cannot move that quickly....