Weak AC on idle, but gets back to normal when car is running

**dr. d** · May 10th, 2014 12:01 AM

Originally Posted by colt

I have the same problem. I had the following parts replaced: filter drier, condenser, evaporator to laminated, expansion valve. A/C cleaning done and flushed. Pressure reading on compressor is normal. Radiator fan is working fine. I also added a 3rd aux fan in front of the condenser.

Kindly advise po kung ano sa tingin ninyo ang pwede pang gawin.

BTW, when car is running at least 30KPH a/c temp can go down up 2-3 degrees C. But when car is idle, it can hardly reach 10-12 degrees C.

I am using a pen type thermoter to monitor the air coming out of the center a/c vent

i found out (the expensive way) that there are two types of evaporators.. the serpentine, and the laminated. one is much more expensive than the other, but i forget which.. when my evaporator sprung a large hole, i had it replaced. i was curious why the bill was much cheaper than i expected. and i also wondered why the shop added another thermostat.. yun pala, they installed the cheaper evaporator, which was not a match to the rest of my otherwise oem system. the aircon could never get cold enough.. i got fed up and simply told them to get me the more expensive evaporator. they installed it, and it was simply voila!
perhaps there is something in your system that is not a match..

**chookchakchenes** · May 10th, 2014 02:45 AM

^
serpentine yung mahal na evaporator and ang kotse mo civic?

**vvti2.0** · May 10th, 2014 05:00 AM

Di kaya idle up ang problema ng sasakyan mo?

**funkeemunkee** · May 10th, 2014 11:47 AM

Originally Posted by poorprince

yes, the aux fan turns on when the compressor engages, when it disengages or i think what they call "trip-off" (clicking sound), the aux fan goes off. Aux Fan Spins again when Compressor re-engages. Same thing with the radiator fan, only spins when reaching a desired temp, then turns off, to save energy perhaps? is my setup ok? thanks!

Ideally, dapat sabay na mag-actuate ang condenser at rad fan when you turn on your aircon. Maybe that's why bitin ang lamig pag idle. You can have the electricals hacked para magsabay na yung dalawang fan. Mas buo lamig pag ganun kesa dun sa rad fan na nag-actuate lang pag init na ang makina. Pa-check mo na lang entire AC system para wala nang tsambahan sa diagnosis.

**jakewise** · May 10th, 2014 12:44 PM

I think it is the other way around as far as I know, mas mahal and laminated sa serpentine evaporators

Originally Posted by chookchakchenes

^
serpentine yung mahal na evaporator and ang kotse mo civic?

**theshepherd** · May 10th, 2014 06:59 PM

Mas mahal laminated evap.

Peace out!

**vvti2.0** · May 11th, 2014 10:56 AM

Sa amin na naka direct ang radiator fan sa makina, meron tinatawag na idle up controller, kapag nagbukas ka ng aircon automatic tataaas ang idling hangang mareach nya desired temperature sa thermostat mo, then mag off ang idle up mag-on ulit ito kapag bumamba ang temperature ng ilang degrees from your target thermostat temp.

So most of the time kung weak ang aircon during idle, may problema ang idle up mo.

**non-vtec** · May 13th, 2014 07:22 PM

Originally Posted by poorprince

yes, the aux fan turns on when the compressor engages, when it disengages or i think what they call "trip-off" (clicking sound), the aux fan goes off. Aux Fan Spins again when Compressor re-engages. Same thing with the radiator fan, only spins when reaching a desired temp, then turns off, to save energy perhaps? is my setup ok? thanks!

Not sure with the Civic's fan setup. But the aux fan is triggered by the compressor, while the rad fan is by the temp sending unit. Or both fans should turn on when the water temp is high. So I think its normal.

First thing you should do is to visit a legit aircon shop. Get the readings from the high side and low side. If you are experiencing high pressure, even when the aux fan is on, it may need replacement na. If not, then maybe your compressor is no longer efficient. When you rev the engine, does the aircon get colder?

**poorprince** · May 14th, 2014 04:26 AM

Originally Posted by non-vtec

Not sure with the Civic's fan setup. But the aux fan is triggered by the compressor, while the rad fan is by the temp sending unit. Or both fans should turn on when the water temp is high. So I think its normal.

First thing you should do is to visit a legit aircon shop. Get the readings from the high side and low side. If you are experiencing high pressure, even when the aux fan is on, it may need replacement na. If not, then maybe your compressor is no longer efficient. When you rev the engine, does the aircon get colder?

yes it does, when i rev the engine, AC gets cooler. what you think it is? also, the summer heat is just different these days, might also be a factor. thanks sir.

**yapoy86** · May 14th, 2014 09:39 AM

Originally Posted by sirkosero

2-3 degrees ang binubuga ng AC mo?! lamig nun! 0 degrees C ang freezing poing of water eh

sarap naman sa kotse mo.. lamig!

BTT may mga kilala ako na naglalagay ng windshield washer na nakatutok sa condenser ng car. para kapag hirap na yung aircon nagsspray sila ng water sa condeser para tumulong palamigin ang cabin.

Sent from my Thrill 430x using Tapatalk 2

Actually, inside the evaporator the temperature can go as low as -5 degrees.. at the vents, air temp should reach as low as 0 degrees to 5 degrees, the "feel" temperature should be at 15 degrees to make the cabin temp at around 20 to 25 degrees..