AC Compressor Growling at Me

Might be my imagination now that I'm tuned in to it, or it might be getting worse. When sitting at a light or parking lot (ie: when there is not a lot of road/wind noise), I'm getting a growling/vibration from the AC compressor when the truck is in gear. When I turn off the fan/AC it stops, so I know it's that. When the truck is in Park, it also does not do it. If I sit with the brake on and put the truck in drive or reverse, it does it as soon as the AC kicks on. Kind of a low reverberation type noise. Pulley? Clutch?

 

Most likely the pulley. But my trucks idle drops some whenever the clutch kicks on and get a little louder. So I really can't give you a straight foward answer without hearing the sound

 

Have you used mechanics ears to take a listen. Mine have a tube on one end to listen to air /noise right near a part and a solid rod for tracing noise through parts bodies. Always have to watch out for the running belts etc. of course.

 

Mine started doing this same thing a week ago and then it tuned in to a growl, then grenaded on me. At the shop now, $1k to replace as I don’t have the time this week to mess with it.

Mentally prepare yourself for that outcome.

 

Might want to not use it for now until can diagnose and hopefully might be able to swap some parts without grenading metal throughout the system. Had an AC compressor clutch go on a taco and was able to have refrigerant evac'd then swapped in a Denso compressor for $185 and a dryer for $22, then had it refilled all for <$275 including the AC service in 2016 IIRC.

 

Oh mine is 100% pulley. And not even the ac pulley. It's the PS pulley. There is obvious play. I'm just putting it off

 

unfortunetly. I will say this, if it's already started making that noise, the odds of contaminants in the system are high. And simply replacing the compressor will just delay the inevitable grenading of the ac compressor.

I'd take it to a shop, spend the shitty, pretty penny. Get the system flushed out and done up proper.

 

Didn't find a shop that didn't want to replace everything in the system including condenser as that was policy to stand behind repair. However, they were willing to evap and refill refrigerant, and could determine the failing parts did not impact the internals.

 

that's protocol in AC shops. My dad's shop was the same. Otherwise we can't and WON'T warranty anything, the threat of contaminants in the system is too risky.

your other option is to replace what you think is the faulty part and have them evac, vaccuum, and refill your system. They won't cover anything with that though. My dad's shop had a waiver for those scenarios.

you can try a ac system flush. That doesn't always work.

 

Exactly. Wasn't offered a waiver so never got a reduced cost quote. So since could determine AC compressor clutch failure not sending debris inside system, was able to swap in a $185 Denso compressor and new $22 dryer istead of swap condensor and hoses, etc. unecesarily.

 

Atleast do a flush to make sure

 

Hmm. Have to learn about how to do that. Remember adding the right amount of PAG oil to the compressor. So reattach and then flush? It been since 2016 and running strong.

 

It’s been a moment since HS shop class but I recall needing specialized machines to evacuate the system. The you have to remove the expansion valve and receiver dryer and use another specialized machine and compressed air to properly flush the components. The you pull a vacuum before adding refrigerant and oil.

 

Yeah I paid a shop maybe 50 IIRC for the evac and refill and didn't have to buy any refrigerant since hadn't lost any.

Looks like there's a video and tools at local parts stores for flushing the evaporator, condensor and hoses.

https://www.autozone.com/diy/climate-control/how-to-flush-your-cars-ac-system