Mercedes AMG GT Hybrid Fuel Consumption and Hissing Sound

A hissing sound combined with increased fuel consumption and a check engine light definitely points to a potential air intake leak An intake hose leak is certainly a plausible cause Has the car been serviced recently Also are you able to pinpoint where the hissing sound is coming from Checking around the intake manifold could provide more clues

No it hasn't been serviced recently I'll try to pinpoint the hissing but honestly I'm not very mechanically inclined If it IS a leak in the air intake is it something that needs immediate attention or can I drive it for a bit I'm worried about causing further damage or engine misfire

Given the symptoms especially the increased fuel consumption and engine light it's best not to drive it more than necessary A leak in the air intake affects the air-fuel mixture potentially leading to engine damage The car's computer is likely trying to compensate hence the higher fuel consumption I would suggest having a professional perform a leak detection test and inspect the intake manifold It sounds like you should take it to a workshop

You were spot on Took it to a local workshop and it turned out to be a cracked intake hose exactly as suspected New hose installed for about 100€ and everything is running smoothly again No more hissing the check engine light is off and the fuel consumption is back to normal Thanks again for the help