eh294

thisguyaves

AC compressor clutch or related electronics are likely to blame. The clutch can be rebuilt, or the AC compressor simply replaced. I would start by making sure your freon is topped off, though.

Also, this would be more at home in the 2001-2005 honda civic model specific forum.

sumdewd

How high is a bit high? Water on the condenser dramatically lowers the high side pressures which may be why it works if it's bouncing off of the high pressure cutoff. Did he drain and charge the correct amount by weight? Are both cooling fans working? I believe the compressors on this year are variable displacement (correct me if I'm wrong) and the pressures mean basically nothing unless you charge by weight with a scale and you measure the ambient temperature and vent temperature.

Clutch air gap on the compressor is another factor. When the gap gets too big (which happens as it heats up) the electromagnetic clutch can't pull the hub in anymore to engage the compressor. You can test this by very carefully tapping the end of the compressor hub that isn't spinning to see if it pulls in and engages.

holmesnmanny

it sounds like the expansion valve is bad and the evaporator is frosting which is triggering the evaporator sensor to turn off the clutch

replace the expansion valve and the receiver drier

sumdewd

That can be checked with a multimeter. A manifold gauge would also reveal a low low-side or vacuum. No need to throw parts at the car without checking the easiest stuff first.

NDNV

Exactly the solution that worked for me. Mechanic removed AC clutch, removed a shim or 2, cleaned surface and voila - problem solved.


skip to 16 minutes

sumdewd

Yeah you just gotta make sure it can still cycle off lol. Great way to trigger the blowout plug or turn the system into a grenade if you remove too many shims since it will refuse to disengage. This defeats every electrical safety the car has on the unit if you mess up.

I bought a "rebuilt" compressor from ADV auto and the clutch slipped and looked worse than my girlfriend's 190k mile clutch on her old comp. I was livid and had to swap the whole clutch out when they refused to warranty it. Luckily I kept the old compressor but I had to play with the damn shims a few times. Sometimes they include 2-3 different sizes and you gotta play with them.

holmesnmanny

If the air gap was the issue it would never turn on. Humidity would make no difference.

holmesnmanny

As the evaporator freezes up refrigerant has a harder time getting through which causes pressure to build up,

sumdewd

Maybe you should watch that second video again at 11:00 where the A/C compressor was working and then kicks off as it warmed up. Then again at about 16:00 where he taps the clutch and it comes back on.

High humidity actually hurts A/C performance, but yes it may not affect the clutch directly. Water sprayed on the hot condenser will evaporate and rapidly cool the condenser. Same reason you get cold when you're soaking wet. If the A/C was shutting down by tripping the high pressure cutoff, or maybe even the air gap is now too big because the clutch warmed up, lowering the high pressure by spraying the condenser can help alleviate the situation.

The evaporator will never fully freeze (block of ice) externally thanks to the temperature cutoff if it works. Now if somebody accidentally brought air/moisture in the system by improper charging then yes, ice may block the expansion valve. But once again it would be reflected with a low low-side or vacuum, and excessive high-side pressure.

The OP needs to have gauges slapped on the car and to verify the compressor is running when the issue is present. And not one of those crappy walmart death kits.

holmesnmanny

The OP has an entirely different scenario than the scenario in that video.

sumdewd

k

holmesnmanny

explain in detail why the clutch gap is within spec until after the same exact amount of time of running the ac

what magically changes the gap ?

sumdewd

Thermal Expansion

tl;dr things expand when they heat up, and contract when cooled.

thisguyaves

And I imagine the simple wear and tear of parts leads to a decrease in performance and efficiency, even electromagnetic. If it's the original AC compressor, it's been in use for 17 years...

holmesnmanny

of course thats the concept but in this particular idea that you are trying to apply it to you have two pieces of metal that are facing each other, if they both expand towards each other then the gap is going to get smaller not larger which means they should not work and then after heating up the gap will get smaller, allowing the clutch to then work

thisguyaves

Heat also negatively effects magnetic strength... Pressure is easiest to check, then clutch I think.

holmesnmanny

if the gap was the issue then it would simply fail to work altogether unless tapped and not just work for a few minutes then stop

sumdewd

Pick one. They're only true if the gap was ridiculously out of spec.

Dude, an actual technician for South Main Auto in that Youtube video outlines the problem in golden detail and even shows the compressor shutting off ON VIDEO when it was already running, then turning back on when tapped, and yet you're still perpetuating this myth. Heat also raises resistance in the field coil like thisguyaves said. Let the OP get back to us and stop acting like Dr. House to get some random dude to spend several hundreds of dollars without helping diagnose the real issue. This is getting tiresome.

holmesnmanny

sure if the cluch shut off at random times and turned back on after tapping it then yes but the OP stated it runs fine and shuts off after the same general amount of minutes

what the OP is describing tells the story of exactly what I described and the OP can confirm by testing the evap sensor before and after it shuts off

sumdewd

Air gap does not shut off at random times. This isn't a roll of the lottery. It shuts off in response to a warmed up compressor or A/C unit.

And TXV icing still doesn't make sense. Rain would lower the overall system pressures which would provoke the evaporator icing condition even more. This is the opposite of what is experienced where he states it cools fantastic in the rain.

He also stated the system works great when it is on, which would really not be the case if there was enough moisture to provoke icing on a TXV. His pressures would skyrocket if this was the case and it would cool poorly in just about any condition.

OP has not reported back to us with at all. There can be no diagnosis at this point. The TXV clog condition is quite exotic compared to a clutch issue. Note he specifically says he does not hear the click of the compressor anymore when it warms up.

holmesnmanny

1. If the air gap was out of spec then it would be a sporadic turn on and turn off. Even in that video the compressor would sporadically still turn on even before he had to hit the clutch.

2. If the air gap was out of spec then the fans would turn on when it was commanding the clutch to turn on.

Civics are notorious for having bad expansion valves. My 06 and 10 civics both had the expansion valve going bad at around 95k-ish and even the evap sensor would not turn off the compressor. The evap lines would frost over and the evap would frost over and no air would be coming out of the vents as a result because it was blocked up with ice across the fins. After swapping out the expansion valve and the drier and not doing anything else the ac has worked perfectly ever since. The evap sensor should be shutting off the ac just like my 91 accord did when it reached 200k and the expansion valve went bad and it has worked perfectly as well after it.

All the OP would have to do is look at the fans when the compressor stops cycling, if the fans stay on then it could be the clutch gap. If the fans are off then it's likely the expansion valve.

sumdewd

I don't get how you don't understand that air gap is not completely random. It's also TOTALLY FREE to check and takes less than 30 minutes with the right tools. Nobody is telling the clutch to go pound sand---it's simply worn out. It is literally mechanically shutting off in response to being warmed up, and it warms up as the system runs. It runs just long enough to click back on for a little bit til it warms back up to disengage.

Your experience is with an entirely different generation with a different problem, on only two cars out of millions, and even then if you replace those parts you have a fresh dry refrigerant drain and fill (if done properly) which completely eliminates the potential air/moisture contamination issue. You had more than one issue since the temperature sensor did not shut the unit off.

My 91 DX (god rest that piece of junk) Had a bad evap temp sensor. It would ice at night in the rain on the freeway. I remember seeing my breath on the expressway then the air eventually stopped flowing as the vent thermometer crept to 20F. It also eventually read 0 psi and didn't cool when we accidentally swapped a bad junkyard evap/txv combo into it to try and rectify this issue.

Care to provide us with a source that states air gap causes 100% random issues? You won't find one. You've now changed your story from never working, to working when tapped, to sporadically working. Link us since we've given you several already on air gap inside of this thread. This is also assuming the A/C switch, blower switch, wiring, relays, fans, fuses, PCM, oil content, pressures, radiator/condenser condition, and charge are fine---none of which has been checked or compared yet against the ambient temperature or humidity of the OP's location.

You have some good posting history and you help a bunch of people out, but don't tell somebody to immediately replace parts because some obscure thing happened to you with a different car. There are dozens of variables that have to be analyzed with an A/C unit before tossing parts at a car. I've seen quite a few messed up situations on these Hondas and a bad TXV is not ruled out. Honda makes flowcharts for a reason.

eh294

eh294