This is an odd question, but something I have noticed since we have already hit the triple digits here in the desert.

When I turn my A/C on recently I noticed that the compressor seems to be cycling on and off intermittently. It is almost as if when the engine overheats and cycles the A/C to keep the heat down. I know how this is becuase I have actually had an overheat to 4 bars when I got a newspaper stuck in my grill last year and the A/C did the same thing.

However, with that in mind, I do not have any obstruction to airflow now - no grill, radiator plate - just normal stock airflow.
And I do not have 4 bars of heat. When I pop the hood after a long drive, the engine is not any hotter than usual, and the aftercooler casing is lukewarm so I know the engine is getting cooler air in the intake.

My question is this - I recently had my injectors changed by the dealer, and was wondering is there a sensor or plug or something that the mechanic could have loosened or removed that would make the compressor cycle if it wasn't getting a proper signal, or is this a sign that the compressor itself may be bad?

Give me your thoughts.

JJ

 

Anyone?

It blows really cold air, warmer air, really cold air, warmer air...it does this at any RPM and even idle and has a cycle of about 1-2 minutes.

Puzzled.

JJ

 

I had a similar problem with my WRX. Supposedly it was due to excessive pressure in the A/C system. Was your A/C recently recharged??

 

all A/C compresors cycle - there is an in-car sensor that helps determine the heat in the car, and the compressor cycles to increase fuel economy, wear on the compressor, excessive icing, etc. There is nothing wrong with your car - if you still think there is, take it to a respected HVAC shop for them to check it out. There is a high pressure switch that cuts off the compressor if it gets so high it could damage the compressor, but it does not cycle in 1-2 minute cycles. Also, make sure wour temp switch is turned counterclockwise as far as it can go into the blue.

 

Hey Doc,

Mine was running the same way the other day. I think it is normal.

-Lee

 

It just seems much more noticable these last few times. I know it normally will cycle, but the temp difference seems to be much more drastic than I remembered it from last year. And of course the temp setting is as far in the blue as it goes.

No, the A/C hasn't been touched since I have owned the car (30+k miles)

I will keep an eye on it to see what happens, and the car seems to run fine otherwise.

Thanks for the input..

JJ

 

Turn the car and AC on and open the hood. Near the passenger side headlight are some AC hoses. One of them contains a little metal cube with a circular window in it. If you see lots of air bubbles flowing around in there, the refrigerant could be contaminated with air and need recharging.

///Robin

 

As mentioned before when the A/C senses hi pressure it will cut out, but also generally when the refrigerant is low in the system, it will have the same effect of shutting on and off to prevent damage to the pump since there is not enough refrigerant/oil to lube the pump. Refrigerant does come with some oil when pumped into the system.

 

Great! I will check that out tomorrow.

Thanks guys.

JJ