"Silent Jackhammer" Sound When AC Running

[HapaHaole]

Originally Posted by aagun

Test your frs

Test for what? using the tech stream I can see the fuel trim move based on the A/F , MAF and even post CAT O2 inputs.

When a car is in open loop, the fuel trim does NOT deviate / move until the ECU sees the ECT at a certain temp. This is text book training for automotive diagnostics.

[vfrqqq]

Originally Posted by cpnslow

I caught it again this morning, and you can hear the "jackhammer" much clearer in this video. It seems to happen when the car is cold, then dissipates over time. I never hear it while moving. I do have quite a few mods, but nothing near the engine that would make this sound.

Boy I'm glad someone else has noticed this too. I thought I was going crazy. My 2014 is bone stock and the only time I would hear it was when coasting at lower speeds withe the clutch disengaged.

[cpnslow]

Update: Stevens Creek Subaru now has my car until they could figure this all out. It's driving me crazy. My coworker seems to think there's a vacuum leak that's causing the engine to run rough, and therefore the AC upsets it. We'll find out on Monday.

[Sookainian]

any update as I've having the same problem

[Sookainian]

no update ?