A/C Is Killing My Car!?

[SoundsLikeStang]

Hey guys! I own a black 2015 V6 Ford Mustang (base model) and I currently have 6,500 miles.


Whenever I first got my car, I would rarely turn on the A/C. I'm more of a "windows down" kind of guy. Only time I would run it would be whenever I have griping passengers that complain that it's "too hot." The car would act fine whenever I would turn on the A/C. Now that July has rolled over and Miami is getting up to 95 degrees, I have rolled up the windows and turned on the air conditioner three times.

I'm not sure if this is normal or not (sucks if it is), but my car has been performing very weirdly here recently-- and it's only whenever I switch on my A/C. Whenever it's running, I feel a sudden jerk and the car is sounding like it can barely stay at idle. No exaggeration, but the tachometer drops heavily and my Mustang sounds like it's about to go dead. It's freaked me out a couple of times to where I have to rev the engine until my light can turn green. Speaking of the engine, my cars performance SUCKS whenever the A/C is running. It takes forever for it to shift into a higher gear and it lags to hell and back. You can even hear every 10-15 seconds some type of noise coming from the passenger compartment that sounds like the A/C is kicking in-- Every car I've owned, I could never hear the A/C component on.

Why is it so bad for the engine whenever you run the A/C? I mean, I do know it's puts strain on the engine-- but how much? I don't want to run the A/C anymore until I know it's not something that will wear fast and/or will put too much strain on my engine.

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[bluebeastsrt]

Oh no....Poor Car turn the AC on and enjoy your not hurting anything but if your worried pop the hood and make sure your AC compressor is turning freely,

 

[XDsm]

AC does put a parasitic drain on your engine. So it's normal for the RPMs to dip briefly and for performance to suffer when running AC. Like bluebeastsrt said, you can make sure your AC compressor is spinning freely but outside of that it's probably normal AC operation.

When I use the AC in my WRX it's like I added 700 lbs to the car. The turbo lag is much worse and shifting can be tricky as the RPMs drop faster with the drain on the engine. Subaru even programs the AC compressor to turn off when you go full throttle so that you will have all power available.

 

[Highwayman]

It's not specific to Subies. All of em will cut out the AC for various reasons. Including rapid throttle apps or WOT.

 

[willmkent]

Oh no....Poor Car turn the AC on and enjoy your not hurting anything but if your worried pop the hood and make sure your AC compressor is turning freely,

lol damn dude you are rough sometimes lol

anyways man, if your car literally feels like its going so low in the rams that it will die then that is not right. You are NOT hurting anything by running the AC at all but the car should properly sustain itself at an appropriate RPM while using the AC... you should feel like the car is about to fall apart and leave you stranded. I would take a video of your concerns, post them here and then take the car to the dealer so that they can diagnose under warranty in case you may have an issue

 

[Hack]

Go to the dealer. They will fix any problem. There shouldn't be a noticeable RPM drop when you turn the air on. The engine computer automatically compensates for the drag.

 

[Anthony 05 GT]

A/C running robs a little power, but usually not that noticeable. You should hear a little change in idle or slight noise, but nothing crazy. I think I would take it in and let a tech or service adviser have a look if it's that bad.

 

[Chameleon]

It definitely robs power but I'll have it on during the day to not roast.

 

[bluebeastsrt]

LOL the second half of my response was serious. Have your wife, girlfriend, buddy sit in the car while you watch The air conditioner compressor. Have them raise the RPMs. Listen for squeaks. Watch the belt to make sure it's not jumping around. And make sure the compressor idler is spinning freely. The compressor is the only part of the AC system that could effect RPMs. If you don't see anything but the problem persists and can be duplicated. Have the dealer fix it under warranty. Good luck.

 

[Anthony 05 GT]

It could also be a software glitch. When the a/c is on the PCM changes fuel delivery especially for idle speed.

 

[asd123321]

If the compressor is bad it could create excessive drag just as I had one at home that wouldn't turn.

 

[wildsailor]

* Snip

Have your wife, girlfriend, buddy sit in the car while you...

* Snip

At the same time? That's a lot of people in a Mustang especially for the two that really hate each other... :lol:

 

[zackmd1]

Hey guys! I own a black 2015 V6 Ford Mustang (base model) and I currently have 6,500 miles.


Whenever I first got my car, I would rarely turn on the A/C. I'm more of a "windows down" kind of guy. Only time I would run it would be whenever I have griping passengers that complain that it's "too hot." The car would act fine whenever I would turn on the A/C. Now that July has rolled over and Miami is getting up to 95 degrees, I have rolled up the windows and turned on the air conditioner three times.

I'm not sure if this is normal or not (sucks if it is), but my car has been performing very weirdly here recently-- and it's only whenever I switch on my A/C. Whenever it's running, I feel a sudden jerk and the car is sounding like it can barely stay at idle. No exaggeration, but the tachometer drops heavily and my Mustang sounds like it's about to go dead. It's freaked me out a couple of times to where I have to rev the engine until my light can turn green. Speaking of the engine, my cars performance SUCKS whenever the A/C is running. It takes forever for it to shift into a higher gear and it lags to hell and back. You can even hear every 10-15 seconds some type of noise coming from the passenger compartment that sounds like the A/C is kicking in-- Every car I've owned, I could never hear the A/C component on.

Why is it so bad for the engine whenever you run the A/C? I mean, I do know it's puts strain on the engine-- but how much? I don't want to run the A/C anymore until I know it's not something that will wear fast and/or will put too much strain on my engine.

What you described in terms of sound from the passenger seat and operation while in drive sounds pretty normal to me. It is amazing how much strain the ac puts on the engine. That being said I have NEVER had the engine come anywhere close to quitting on me at idle. It does dip in the rpm range when the compressor kits in but it is only a 100 rpm drop and then its right back to normal.

Your car could be having an issue with the compressor. The compressor might not be operating correctly which could cause increased load on the engine. I would take it to a dealer and have them check it out. Make sure you can replicate the problem when you go.

 

[jrt6]

I'm going to take a guess at the compressor too. Yes they do have a parasitic drag on the engine but it shouldn't be enough to affect idle THAT much or suck that much power out of your engine.

Like someone said before, have someone cycle the A/C on and off while you watch the compressor. See if its spinning freely and activating properly. Try and see if you can get it on video too, because we all know that somehow cars love to work perfectly the moment you roll into the dealership.

The only car I've ever had issues with the A/C affecting idle was my 4 banger camry i traded the mustang for. Every time the A/C compressor came on the car would vibrate, you could see it in any water bottles you had in the car, and if you added a electrical drag (like using the power windows) at idle the vibration got worse.

 

[GT Pony]

Doesn't sound quite right ... the AC shouldn't drag the engine down that much. Have the dealer check it out.

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