Mercedes GLA hybrid hissing sound and fuel issue

Whoa, that sounds familiar I've got a Mercedes C-Class, and I had a similar thing happen last year Check engine light and a hissing sound too I never thought about fuel economy though, I should have Was the hissing sound constant, or only when the engine was under load It ended up being a cracked intake hose for me Made a world of difference once I got it sorted Is the hissing really loud

Thanks for the quick reply The hissing is definitely louder when I'm accelerating, so yeah, under load It's subtle at idle, but put your foot down, and it's like a snake is living under the hood So, it was the intake hose for you, huh Did you find it yourself, or did you have to take it in And how much did that set you back

I couldn't find the leak myself to be honest I took it to a workshop The mechanic used some kind of smoke machine for leak detection They found a small crack in the vacuum hose connected to the intake manifold I would recommend going to a workshop Good luck

Awesome, thanks a million Vacuum hose makes sense I'll bite the bullet and get it to the workshop I suspected as much, but having someone else confirm it helps They found a split in the intake hose New hose, labor, and diagnostics came to about 100€ Fuel economy is back to normal, hissing is gone, and the check engine light is off Appreciate the help