So the AC died on my 2015, and when I went to look and see if the compressor clutch was engaging, it was not. That's when I noticed a weird, low, clunking noise that came and went in the engine (proceeded to drive 100ish more miles). Kinda sounds like this, but louder: . Mechanic said it was a bit low on oil (no oil on the dipstick that I can't ever seem to read... why is it plastic?) so we're changing that despite the MM reading 20%, but his advice was to see if the clunking noise goes away before investing in the AC repair, since the clunking could be real bad.

I'm thinking it could be the bearing on the AC compressor pulley, given the timing, and the fact that the oil light has never come on. In order to test that I need to pull the serpentine belt, run the engine for 15 seconds at idle, and then put the belt back on... Has anyone done it on a '15 or newer? I can't find a belt routing diagram or a video of one anywhere. Could I do it from the top of the engine only, or do I need to get under it because of how small the space is? And is it a 3/8" drive hole, or do I need a socket on the end of one of the tensioner arm tool thingies? I suppose I could pull it off the drive pulley and try to run it with the belt still wrapped around all the other pulleys, but that seems dangerous.

I also had the VTC actuator replaced last year under warranty if that could have anything to do with any of this, but I'm assuming it's unrelated.

Not real excited about replacing the AC compressor at 5 years and 61K miles. Should I replace anything else while they're doing that (water pump, tensioner, belt, etc.)?

Also I don't have my manual in front of me, but I remember it saying to change the oil when the maintenance minder says to, and I don't remember it saying to change yearly if the maintenance minder doesn't pop up. When I looked up a manual online though, there was an asterisk and a bit at the bottom saying to replace the oil if it's been a year+ and the minder hasn't popped? I've been doing mine when the wrench comes on, which has been roughly every 15K miles, at times between 9 months and 2 years. Should I start doing it annually if the wrench doesn't pop up?

 

First, spray some WD40 all over to see if the noise goes away. If you assessment is that the compressor clutch is not kicking in, you shouldn't have cold air. Sometimes, rust will hold up the clutch. In my BMW, I used a hammer to give the compressor a wack, and that resolved the clutch not kicking in. Safe bet is change the oil/filter when the mm displays 20%. I would have gone about 9000+ at that point. I am surprised that your oil so low that you can't read it. Try hard, plastic or metal you should be able to read the dip stick!

 

... What? I'm absolutely not spraying WD40 all over my engine bay lol.

I have "outside temperature" air, but it's not cold, because without the compressor, the AC can't cool the air.

I got the car back today with a quote for $800ish to replace the AC compressor, and $4K for a new engine if I want to go that route. Going to take the belt off and see if the noise goes away. For anyone else who's curious, it's a 17mm wrench point, not a 3/8" socket hole like my other cars, and it seems designed to be operated from below, given that there's an engine mount right above it. Going to try using a short wrench and pulling it from the top, but I don't know if I'll be able to get enough torque. I'll update here later.

 

I made the correction from should to shouldn't have cold air. Well, it seems like you have a plan to find the root cause of the noise you are getting. Keep us updated.

 

Gotcha, was confused, makes more sense now. After listening to it more it does sound a lot more like that video than I previously thought. Should know if the issue is the compressor bearing/wheel or whatever it's called by tomorrow morning. I will keep updates coming.

 

This thread got moved hard lol... Anyway, I took the belt off, noise went away. Put it back on, noise is back. Took it off again, noise went away. Pretty sure it's the AC compressor wheel.