We have a 2014 Subaru Forrester whose AC Compressor clutch operation is unlike other cars I've ever owned. The video linked is from when the car is cold and AC is engaged. It appears that the clutch is slipping for the first few seconds, but the loud buzzing and noise accompanying engagement remain until warm. The clutch engages fully once warm as well.

According to the dealership this is all normal and refuse to replace the compressor until it completely fails and don't care that the noise makes the vehicle sound like a junker. Careless; considering a slipping clutch will eventually lead to bearing failure, a break of the serpentine belt, and overheating of the engine leaving us stranded.

I know that others have had this fixed under warranty, so I'm wondering how to have this repaired without voiding the warranty by bringing it to a shop other than the dealership. Perhaps another dealership is my only option?

Edit: After visiting the dealer to pick up the car and debating things with the tech who reviewed the operation, he claimed that this vehicle's compressor clutch needs to warm up to engage fully, and again the buzzing is normal until warm. My question would be, what magnetic clutch which is properly gapped, needs to have its friction surfaces heated before it'll catch completely? As far as I'm aware, the clutch is either engaged fully, or disengaged fully. There is no gradual application of pressure. If this was normal operation, would it not be expected to occur every time, and not intermittently depending upon engine, pulley and, ambient temperatures?

I can only guess the buzzing noise is a symptom of the slippage.

I believe I'm being lead on, but would like a professional to weigh in.


  • First thing to do is take it to a different dealership without telling them you've already taken it to a dealership already. You may check with other Subie owners in your area if they have a preference for the better dealerships which may be more willing to help. If the second dealership doesn't want to repair it, you have recourse to take it up the Subaru chain. Area Subaru management may be willing to help you. I don't understand why they aren't willing to help you, mainly because the local dealership doesn't incur the cost of warranty repairs. Commented Aug 29, 2015 at 15:51
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    After viewing the video and looking at the compressor in person, they claim that the noise and slippage is normal. "The pulley has to warm up first" they say. I had to cry a little. I'll try that, but ended up getting on the phone with Subaru Corporate. They'll be contacting them to find why they considering this normal.
    – ethesx
    Commented Aug 29, 2015 at 16:46
  • Completely slipped my mind, much appreciated. I'll have to attach an after video/pics as well.
    – ethesx
    Commented Jan 6, 2016 at 1:36

1 Answer 1


Ultimately, I had to make enough of a stink with the original dealer citing the operation of other compressors to have the component replaced. Subaru America was of no help as they weren't even able to get the service manager to call them back.

Addition Info: The dealership claimed they were only doing this for customer satisfaction and at no point agreed that the compressor or parts were malfunctioning. They opted not to review the video and made the claim that this vehicle's clutch operated as designed (gradually engaging magnetic clutch), but considering the replacement's operation, see this is not the case.

The compressor has since been replaced, and has been working with no issues (so far). The pulley is engaged fully when the clutch is energized and there is no extended buzzing.

The compressor, its clutch, and pulley look a bit different then the original.

Pictures, video to follow.

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