2016 CX-5 AC compressor cycles every 5 seconds?

[cdmain]

Dear Mazda forum members,

Need your help again please.

Noticed this on my Mazda CX-5 2016 GT , with AC on set at 18C , the car will vibrate every 5 seconds, can feel it when I am sitting at the lights , vibration through the brake pedal . Turns out the AC compressors is cycling on/off but it only happens when AC set to recirculate.

When the AC is set to take in outside air , the compressor stays on.

Is this normal? Video attached.

 

[cdmain]

Ok did some further tests and it seems even with recirculate off, if I raise the temperature setting to above outside temperature , the same cycling occurs.

In the video I don't show the AC compressors but it does switch on and off with the fans every 5 seconds.

 

[cadcamjim]

I would say that is likely normal. That's the way fixed-displacement a/c compressors work. The only way to keep the evaporator at a constant temperature is to cycle the compressor on and off as needed. My 2021 CX-5 will often act the same as yours; like you saw it depends on other factors; ambient temperature, HVAC settings, etc.

My previous car, a SAAB 9-3 had a variable displacement compressor, and the compressor would stay engaged anytime the A/C mode was selected and ambient temperature was above about 30 degrees F. Evaporator temperature was regulated by mechanically changing the displacement within the compressor. A much less annoying system.

 

[cdmain]

Hi Cadcamjim,

Thank you very much for the reply.

I'm starting to like the variable displacement compressor design.

I still don't understand why in the Mazda the compressor will stay on when the temp is set to lowest setting 18C and recirculate is turned off.

Since the evaporator freezing should still be an issue the compressor should cut out at the same frequency to maintain the temperature of 18C right? Instead I find the compressor is on for as long as I was watching it probably a minute before switching recirculate on and it started cutting in and out every 5 seconds again, temp still set at 18C.

Do you still think it's normal behaviour? Won't this rapid cycling cause damage to the compressor?

 

[cadcamjim]

With recirc off, the warmer outside air passing thru the evaporator forces the compressor to stay running longer. There is usually an "anti-icing" thermostat at the evaporator that opens and closes to signal whether or not the compressor should be running or not. I have a display on my phone using the OBD2 Fusion app that will show, along with hundreds of other parameters, if the compressor actually is running or not. The compressor cycling is usually more frequent at idle than while your moving so it's probably not cycling as much as you think it is all of the time.

Cars have been using this technology for decades. Yeah there is some wear and tear from all this cycling, but they are designed to withstand that for many years.

 

[cdmain]

That makes sense to me now. It's a relief to know this is normal. I guess I will use recirculate off more often now in order to avoid the annoying cycling .

Much appreciated . You guys are awesome and I'm really grateful to be part of this forum.

 

[N7turbo]

I use recirc most of the time because I don't like my interior smelling like exhaust gas. I guess I'm used to the way the car behaves.

 

[cdmain]

Hi N7turbo,

I understand what you mean. I have a hepa carbon cabin air filter that takes care of smells like that. But it sure does restrict air flow. I need to have the blower on max most of the time.

I never noticed the compressor cycling until recently. Used to drive another car and have just switch to the Mazda recently.

Seems like on the 2019 model Mazda switched to variable displacement compressor I read , but Cadcamjim has a 2021 model that does the same cycling so not really sure if that's true.

 

[HyFlyer]

... I have a hepa carbon cabin air filter that takes care of smells like that. But it sure does restrict air flow. I need to have the blower on max most of the time. ...

That could be a cause of the AC compressor cycling more often ... Airflow restriction due to the filter. Maybe a new filter is in order?

 

[cdmain]

Hi Hyflyer,

Thanks for the reply. I don't think that's it because it does not cycle when the recirculate is set to off and temp to 18C. Air filter should still interfere in this scenario, right?.

 

[cdmain]

Well I got a new cabin air filter installed. This time just a plain old pollen filter. None of that charcoal/carbon activated stuff. The old filter I had was quite restrictive to airflow, been that way since the day I installed it. So it turns out you were right HyFlyer!! Thanks very much for the tip.

The airflow was insufficient on every fan blower settings except the max, to keep the evaporater from freezing. This cause the compressor to short cycle more that anything else.

With the new filter the compressor still cycles on idle but takes much longer that 5 seconds , more like 1 min+, unless I have it on the lowest fan blower setting.

Thanks to all of you that responded cadcamjim, N7turbo and HyFlyer , much appreciated.

Unfortunately I'm back to smelling gasoline fumes from the blasted Mustangs screaming past

 

[hsdejong]

I use a MANN cabin air filter with activated carbon with polyphenol, antibacterial, fungicidal, particulate filter (PM 2.5) which does not restricts the airflow more than the standard Mazda cabin air filter.

I don't know about the Mazda CX-5 2016 GT, but in my CX-5 2023 Exclusive-Line I just use the climate control in the automatic mode. In my experience it knows best ;-)

Only while raining I will divert the air (partially) to the windscreen and the last minutes of the ride I switch off the AC to let the evaporator dry to prevent fungus and bad smell.
And depending on the weather, I temporarily use the defrost mode after getting in the car.

 

[HyFlyer]

@cdmain , glad to hear you have improvement. You could try the HEPA carbon filter again and see how a brand new one behaves and compares to the factory style (factory filter has carbon in it as well). It may just need changed more often than a factory style.

 

[hsdejong]

There was a very good explanation from "eugene_naz27" on Reddit in the thread "CX5 Hvac system set to auto?" about the automatic climate control.

CX5 Hvac system set to auto?

In brief: Just leave the climate control in the automatic mode...

 

[hsdejong]

factory filter has carbon in it as well

Not in my car...

 

[cdmain]

I’m just glad the car does not have a fault with the compressor.

Have other issues with this car that I am working out…..first time owning a DI engine and finding this car not as smooth as others I have owned on idle. Seems like I have a random cylinder misfire that is only detected on mode6 tests, but that’s another issue.

Will try the auto mode next time I need to use the AC , reading from that link it sounds like it’s quite sophisticated.

Thank you all for your assistance.

 

[cz5gt]

seems 2024 adds variable AC compressor.

 

[cz5gt]

I’m just glad the car does not have a fault with the compressor.

Have other issues with this car that I am working out…..first time owning a DI engine and finding this car not as smooth as others I have owned on idle. Seems like I have a random cylinder misfire that is only detected on mode6 tests, but that’s another issue.

Will try the auto mode next time I need to use the AC , reading from that link it sounds like it’s quite sophisticated.

Thank you all for your assistance.

try putting normal fuel in it and not the crappy 87.
Thats of course if everything else is in order with ignition/engine.

 

[cdmain]

Good to know Mazda went with variable compressor design in their latest model.

I have been to the mechanic and he told me the same after ruling out spark plugs, ignition coils etc. I had been using 91RON but now I have been asked to use 98RON for 3 tanks and drop a bottle of fuel cleaner in each time. Then bring it back to the mechanic if the issue persists.

I am on the second tank now and the issue is still present so I am not convinced its the fuel injector. Though the issue I have is random misfires across all cylinders but cylinder 4 is worst. Each time I start the engine its a different cylinder+ cylinder 4 that shows incrementing misfire counts but mainly on idle.

I concerned it is carbon build upon the intake valves.

 

[cz5gt]

oh you ar outside of US, so ignore the 87 comment then

carbon build up is a problem yes. One way is to look with a camera and see whats the condition.
and the DI injectors are though to clean with fluids. Good part is they can be removed and cleaned properly. There are also refurbished ones. if the problem is injectors of course.