Q: Engine surging on 2008 audi a4 Quattro

asked by on December 27, 2016

Hello, I have a 2008 audi a4 Quattro and my issue with the car right now is engine surging. The problem is bad when engine is cold but the problem persists even after the vehicle is at optimum running temperature. I have brand new spark plugs and coils, changed oil, new fuel filter. Not sure what the problem could be at this point but it is annoying as I can't figure out what it might be. Definitelt not the transmission as I have gotten that checked out recently. Feeling a vibration everytime the RPM drops and goes back up while driving. Another issue I'm having is when I have my vehicle in Sport mode, I hear and loud growling type sound around 2500 rpm on every gear, not sure if it's a driveshaft issue or something else. Turbo is brand new and I can hear the sound when in park and reviews he engine also.

My car has 112,213miles.
My car has an automatic transmission.

Mass Airflow Sensor Replacement $188.36 - $786.53 Get a Quote

Hi There, What you are describing is a common problem with a dirty or faulty mass air flow sensor. The mass air flow sensor monitors air intake as it is mixed with fuel prior to being injected into the motor. This sensor relays vital information to the ECM which uses this to make adjustments to fuel supply to the motor. A dirty or faulty sensor can cause an imbalanced air/fuel load to be supplied to the motor which results in an over fueling or under fueling situation depending on the conditions. This type of inconsistent fuel supply to the motor may cause a hesitation, loss of power, a jerking reaction, potentially a bit of black exhaust smoke and typically a strong smell of fuel when this sensor is malfunctioning. I would suggest having a professional from Your Mechanic come to your home to diagnose your mass air flow sensor.

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