ok i have a 09 fit sport and ive been having a/c troubles, warm air out the vents at idle and on the highway ( i think it cycles to much) and a hissing noise under the hood at the a/c compressor ( like a leak). so its been at 2 dealerships and they both say its normal WTF its not my condenser cause i have done the wire mesh mod and their is no damage. anyone else with these problems? i'm trying a 3rd dealer thursday but this really makes me mad a 2 month old car with a/c issues already

 

peg, we had the first real warm spell of the season up here last week, and I noticed the excessive on/off cycling of the compressor on mine for the first time. I've never had an air conditioner on another car that cycled as rapidly as this. There are a number of threads about this, so it may be "normal", but it's still not good.

 

Mine hisses too.....

 

Uncle Gary: i know ive searched the threads i guess i needed to vent some, mine cycles every 55 seconds ive timed it and thats way to much imo thats why i think i have a problem with mine.
reako: how long does yours do it? mine hisses for almost 20 minutes and its not the drain tube its near the line at the compressor like a slow leak.
well hopefully the dealer i take it to today finds something wrong or i might start thinking about trading.

 

I hear a hissing noise when I accelerate the car and stops when I put my foot off the accelerator pedal. Is this the hissing noise ur talking about?

 

no mine does it after ive driven it with the a/c on and park it keys out and it not running.

 

Not enough air flow to the condenser due to you mod, Just another possibility?

 

edit: nevermind, my 07-08 fit is like that too so i was gonna say it's normal but i just realized yours is the newer gen fit

 

I haven't timed mine, but mine feels like it cycles on/off at least once a minute. That means it alternately blows warm and cold air. I've never had an air conditioned car do this before. As I said, it may be normal, but I'll agree that it blows (and not in a good way).

 

I get a hissing noise in my GD3 only when the AC is on and I'm accelerating around 4-5k rpm.

 

well i just got back from the dealer and of course they say its normal even with vent temps at 48-49 degrees which i think is bull shit. ive seen post where is supposed to be in the low 40's and that leads me to believe honda dealers don't care about anything so i guess i'll be calling hoa and hear their bullshit. this is the funny thing next door to the honda dealer is a toyota dealer so i drove a 09 corolla s sedan the a/c never blew warm any. then i drove a 09 prius < i figured a 98 hp hybrid would have awfull a/c nope 100 times better then my fit.i hate to say it but i might be trading soon and it won't be for another honda.

 

I hear it most often when I'm cruising the highway at night... I start to notice that faint hissing noise along with each AC condenser cycle. At some points it can get pretty noticeable, especially if you hit the accelerator, it hisses even louder.

 

Mine does cycle on and off a lot, but I have not noticed changes in temperature from the vents or the hissing sound. On the way home today I will pay more attention. I really dislike the cycling on and off though. At night I can see the headlights go dim and then brighter every time the AC cycles. Let us know what HOA says.

 

That sucks man! Everyone has a tipping point or "deal killer" when it comes to cars, and it looks like yours is AC vent temperatures. If the car were mine, I would try just a few other things before I gave up on it. Adding window tint all around, and a "sun strip" on the windshield to block out the sun's rays can aid in keeping the cabin cool, and some window visors and crack open those windows the first couple minutes you drive in the heat...even little things like experimenting with fan speed and vent direction and adjustments. Of course none of this will make your AC temperature lower, if you really wanted to do something like that, it's possible: Modify the A/C to give cooler temperatures

I hope you find what your looking for out there, even if it means trading in your Fit, just keep in mind that there are always compromises and some "give and take" with every vehicle.

 

A/C systems normally operate on a feedback loop from the thermostat. On the Fit the thermostat is the dial you set to adjust the cold. Let's say that you have it set for maximum cold.

IME, when there is rapid cycling like this, it is mainly due to the thermostat sensor being off its mounting and making direct contact with the evaporator coils themselves. Therefore, the thermostat is now measuring the temperature of the coils (which can get VERY cold, VERY quickly), not the air flow temperature. Thus, your compressor beings to cycle and your vent temperature doesn't get "cold."

Another cause for rapid cycling can be a clogged expansion valve. The expansion valve is a sort of safety value that regulates the flow of freon in order to keep the evaporator from freezing over. A frozen evaporator does not permit air to effectively pass through it. The ice clogs the coils.

Let's say that the expansion valve is clogged (or partially clogged). The high-side pressure (output of the compressor) would then go sky-high since the freon flow into the evaporator is being restricted. The low-side pressure (input to the compressor) would fall dramatically and the compressor may pull a vacuum. The system may have a safety sensor to avoid vacuums or over pressure that that will trigger the compressor to cycle off.

The big delta in pressure between the compressor high-side and compressor low-side could account for the hissing sound that peg_leg is experiencing. When the compressor turns off, the high-side and low-side pressures need to equalize. Otherwise, there would be too much head-pressure on the high-side that the compressor would not start back up!

So if your expansion valve is fully clogged, you will not get any "cold" air out of the vents (at all). Since peg_leg is reporting partially cold air, I'd venture a guess that the valve is not fully clogged.

If your expansion valve is even partially clogged, you will get "mildly cold" air out of the vents. This is because the freon is "boiling" at the wrong point in the system (ie before reaching the evaporator coils) due to the pressure issue from the clog. The "boiling" of the freon is the change in pressure that represents the heat transfer. A more simplistic explanation is that the right flow rate of freon is not reaching the evaporator coils and therefore can't transfer heat adequately.

The expansion valve clog could come from some metallic filings from the compressor. Everyone is concerned about engine oil and those metallic filings. At least the engine has an oil filter. A/C systems have oil but no good filter. Usually there's just a mesh screen in the compressor to catch any metallic filings.

Alternatively, peg_leg could simply be low in freon. That would explain the cycling (low pressure on the low-side triggers the low pressure safety). Low pressure also means less heat transfer (aka non-optimal vent temperatures). Low freon could also greate a large delta in pressure between the high and low sides of the compressor. That would cause hissing as that pressure is equalized when the compressor cycles off.

Clogged Expansion Valve: Low side is very low pressure or a vacuum while the high side pressure is sky high.

Low Freon: Low side is very low pressure or a vacuum while the high side pressure is also lower than normal. Look at the slight-glass on the receiver/dryer, you'll see bubbles. If the system is full, there will be no bubbles and you'll see clear or milky white (milky white is the oil being circulated). Unfortunately, newer cars usually don't include a sight glass on the receiver dryer.

The only way to check for sure is to hook up a set of freon gauges to measure the high-side and low-side pressures of the compressor. Older cars have two nipples. You add freon to the low-side and measure the low-side pressure there. You don't add freon to the high-side, but you do measure the pressure there to check if the system is "full."

The low-side tap is usually on the back of the compressor, and the high-side tap is usually near the receiver/dryer.

Newer cars usually only have one-nipple; the low-side to add freon. So all you can do is keep adding freon until the system no longer pulls a vacuum, the vent temperatures are appropriate, and you know the system is full.

Unfortunately I don't own a Fit....yet. But hopefully what I've posted above helps you out.

 

thanks warren, its not the expansion valve i had my dad's mechanic check this out and in the morning he is checking the freon charge. the 09 fit has two nipples so checking the freon level should be easy. if this mechanic finds the level low i'm going back to my dealer and raise some hell thanks for the help fellow freaks.

 

What as the verdict peg_leg? I'm having some AC issues with my Fit as well.

 

You should put a temperature gage or thermometer at the outlet vent and measure the exit cold air. If its more than 55F with coldest setting then the A/C isn't A/Cing. Hissing indeed could be a leak and your trouble may be a shortage of A/c fluid 131. And take at least 15 minutes driving around, not idling.

 

nothing yet i'm getting it put on gauges this next week.

the dealerships drove it around and got 47.6 from the vents i think that's to high. and i think honda knows its a problem the way the dealerships act about it.

 

I have had an S2000 for 7+ years, and the a/c on that Honda also cycles quite a bit, going between fairly cold and not-so-cold about every minute. The cure is to make use of the recirculate function on very hot days. There doesn't seem to be a problem with excessive humidity buildup inside the car, and it does radically increase the power of the a/c. On the good side, the vehicle has gone all these years never needing a recharge. I suspect it's just the way Honda builds its compressor systems.