Poor Air Conditioner Performance

Only Human

Well-Known Member
24
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So I couldn't find a thread where people were complaining about their AC.

I have 14 Si and the air conditioner performs very poorly. In 90F weather, I get only like 55-60F at the vent for 30-45 minutes before I really feel the cold at the vent. It happens quicker if on the highway as expected.

The dealer did an evac and recharge but no change if not worse.

How is everybody's AC?

Do I just accept that its crappy or make the dealer figure out if something is wrong.
 

webby

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Take it back to the dealer. 55-60 degree air is not normal, and they cannot argue that. If they say it needs charged again you obviously have a problem.
 

Nomar06

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I have a 15 Si with 20k miles. It takes maybe 5 mins in 90-100 degree weather before it get super cold. The whole inside cabin gets cold in 10 mins.

Never measured the temp of the air coming out.
 

Only Human

Well-Known Member
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OK, so, maybe my thermometer wasn't seated correctly but, while driving, cooling is actually good in 92 degree weather with sun (~50F) , but I have the following concerns.

1. When idling at a red light for example, the AC air goes up a few degrees. While this is expected, it is significant enough to notice and worry about it. However, both the compressor and the condenser fans are on (low speed) as normal.

Is this commonly experienced with our Si's that the vent temperature swing is very noticeable?

2. Now that I'm really "listening" to the system, I feel a light jolt of power when the compressor clutch disengages. I know that this is normal as compressor stops sucking power, but its quite noticeable.

Is this commonly experienced too?
 

webby

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I've never had a car that was any different. Are you using the recirculation?
 

Only Human

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I've never had a car that was any different. Are you using the recirculation?

You never owned a car that didn't get super cold in 5 minutes or never owned a car that didn't do what I'm describing?

My AC gets cold fast too, but the cold isn't consistent, especially in the first 15 minutes. When the compressor cycles off, the rise in vent temperature quite noticeable. Happens every 3-5 seconds. Like, makes you say, something wrong? and then it gets to really cold again.

Is this normal?
 

webby

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2. Now that I'm really "listening" to the system, I feel a light jolt of power when the compressor clutch disengages. I know that this is normal as compressor stops sucking power, but its quite noticeable.
I've never had a car where I didn't feel the ac engage. I've had v8's, v6's, turbo 4's, and 4cyl and they all did it.
 

Loppysaurusrex

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I have the same problem and sometime feels like the compressor is going out as sometimes instead of cold air it blows hot air
Eh maybe not lol, I live in the south and it gets into the 90's regularly, I have to have max AC on quite a lot to get any cold

I think the real culprit is that my car is black and the seats

The seats hug your body heat in and hold it against you.

I feel like my 5% tint on all sides except for front should help but I guess not lol
 

PR k24

Well-Known Member
17
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Eh maybe not lol, I live in the south and it gets into the 90's regularly, I have to have max AC on quite a lot to get any cold

I think the real culprit is that my car is black and the seats

The seats hug your body heat in and hold it against you.

I feel like my 5% tint on all sides except for front should help but I guess not lol
I feel you I live in Puerto Rico 95+ weather all year round and to make it worse i have a black 4dr Si but i know my ac has something wrong because I have had 2000 black civic si and on the contrary the car had freezing cold air. I guess I'm going to take it in to the shop to check the ac system.
 

Darkout

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They may just say your a/c is working within specs. Every manufacture has different "standards" but the general rule of thumb that I was taught and go by is if the vent temp is 40 degrees's colder or more your system is ok. 45-50 vent temp in a 95 degree heat with high humidity is pretty solid of a number, the fluctuations with the compressor cycling sounds some what normal and mine does it but only noticed it since the heat's been really high. You may notice a 5 degree temp swing from driving vs not moving at a stop light due to compressor speed and air flow over the condenser. Ultimately though if you feel it an issue bring it in but don't be caught off guard if they can't find anything wrong and say it's fine.

These new systems are also way smaller of a charge than older models. Some are less than 1lb while most older systems had 1 1/2 to 2 1/2 lbs. Also could be a factor
 

Only Human

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24
11
Just as a recap though - My AC was "underperforming." It was cycling between like cold to warm to back to cold - I've heard this complaint on other forums as well. But at the same time, there were people saying their A/C was ice cold.

I messed with the system. Too much. Even though it was doing better with a little bit more charge, I ended up putting too much just like any other idiot out there. So in the end, I took it to the dealer and had to pay out of pocket to evac and recharge the system.

BUT, and a major BUT. Right after the recharge, there wasn't a difference. But the next day, and for a month now, the A/C has been "ice cold" with minimal temperature fluctuations. The car did need to sit like over night to equalize or something.

So, in the end, I'm happy that I messed with it, which finally got me the results I was looking for.

For anybody complaining about A/C performance, it may be worthwhile to take it to the dealer, let them do the "A/C performance evaluation" and evac and recharge the system on warranty. Give it a couple of days if you don't feel a difference.
 

alaudin.tamoor

Active Member
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0
My Civic A/C working very fine when car is idle, or at low speed (or may be at lower gears ratio)

But it stop working at high speed (around 80 km/h) or on higher gear ratio

when outside temperature is fine/lower. it works fine on higher speed/ high gear ration like in the evening/night its freezing chilly

Troubleshooting steps taken so for

  1. Gas refilled, compressor oil refilled
  2. AC expansion valve changed
  3. Radiator and evaporator leakage testing and cleaning
  4. Cabin filter and radiator filter replaced with new one
    Nothing worked
  5. generator voltages are checked and found normal
What could be the possible cause and how to resolve it

Thank you !
 

aZnCdn

Well-Known Member
21
27
My Civic A/C working very fine when car is idle, or at low speed (or may be at lower gears ratio)

But it stop working at high speed (around 80 km/h) or on higher gear ratio

when outside temperature is fine/lower. it works fine on higher speed/ high gear ration like in the evening/night its freezing chilly

Troubleshooting steps taken so for

  1. Gas refilled, compressor oil refilled
  2. AC expansion valve changed
  3. Radiator and evaporator leakage testing and cleaning
  4. Cabin filter and radiator filter replaced with new one
    Nothing worked
  5. generator voltages are checked and found normal
What could be the possible cause and how to resolve it

Thank you !
I have same issue. Started about three years ago. Did you ever find a solution?
 

Only Human

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@Janz3n @aZnCdn - so, saga of my AC issues, I had the same problem last year. AC would cut of if driving with high revs for a bit, and too hot outside.

On another forum, people said, "that's normal - ECU shuts AC down" so that the compressor doesn't spin too fast for too long. I didn't believe it, because it was happening way too often and too quickly.

My observation and solution:

I would walk around parking lots and notice that people's cars' condenser fans would be running at full speed full-time. Mine, would turn on and off as if it weren't very hot outside.

In summer of 2021, I bought a full set of AC gauges, high and low monitor, hooked them up and monitored the pressures in 95F weather (in the shade). The high side was below 200 PSI. I hooked up a bottle of refrigerant on the low side and gave it a couple of bursts. The high pressure went up slightly, and noticed the fans would come on more frequently and stay on longer. This is consistent with increased condenser pressure and thus temperature. It was also blowing colder inside.

I gave a few more bursts to bring the high pressure up to 225 PSI. It was blowing "ice cold" inside (not literally - more like how it should be). Fans were staying on as well.

Ever since then, the AC system did not shut off once. And started behaving a lot more like the way it should. Fans would cycle just fine when it is not THAT hot outside (80-85F). Blow nice and cold air.

The compressor relies on the refrigerant to cool itself too. If there wasn't enough refrigerant, at high revs, it may have been overheating. Now that it has "enough" refrigerant, it never shuts off.

Now, summer of 2022, the AC is back to working wonderfully - ice cold inside, never shutting off. And I haven't touched it since last summer.

When I had mine recharged at a shop, maybe they only put in the minimum required amount, or less (off-calibration weight scale) and it simply wasn't enough refrigerant.
 

Janz3n

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I'm confused. You said it was fixed by taking it to the dealer in 2016 as well. Sounds like it's leaking.
 

Only Human

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11
I'm confused. You said it was fixed by taking it to the dealer in 2016 as well. Sounds like it's leaking.
Maybe, but very very slow if so, but I don't think so. I see that I had described the AC back then as "ice cold" as well, but it is a very relative term. It was colder than it used to be after the recharge, but still not "amazing." And one year after that, the compressor started shutting off if I drove hard for a little bit in very hot weather. Now, the AC is amazing even in 95-100F weather and it never shuts off.
 
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