We were coming home from an 8 hour return trip and A/C wasn’t cooling right. We stopped and the A/C lines under hood frozen over. Probably evaporator as well. Shut off A/C for while and it melted off. Turned it on later and it was cooling again. Cooling last two days on shorter trips. I took it to great local shop today and freon was 9 ounces low. Evacuated system and added freon. He said possible leak, so they also put dye in system.

He checked vacuum and it held. He said that this doesn’t necessarily mean there isn’t a leak? He said to continue driving vehicle and if this happens again, just bring it in and they can find leak with dye. $83 out the door for the freon and service. Crossing fingers.

Edit: Just an update. We drove around town for about 1.5 hours. The A/C was running great and cold, no freeze up and compressor is cycling just fine. All well thus far.

 

I have a 09 Fit and I had this same thing happen a few years ago on a 800 mile trip. I later evacuated my system and recharged with 14 oz. using a digital scale. Vacuumed for about 45 minutes and watched gauges about another 45 minutes with no leaks. Problem solved after that. Charge range for my Fit is 13.1 min to 14.8 max ounces. I have seen other posts that mention replacing the thermistor on the evaporator coil that cycles the compressor. But it’s not easy to get to this part and evaporator must be removed and system naturally empty. Dirty cabin filter that is restricting airflow across the evaporator might be an issue but mechanic hopefully looked at this also. Hopefully you are good to go for now.

 

Thanks for the very informative post. Sounds like we had similar issue. Hoping for same results here. I checked the cabin filter myself and it was clean. On our long ride around town yesterday, the compressor was cycling fine as well.

 

Welp.. that didn’t last long. Bad news. Making clunking noises. Opened hood looks like the compressor was cycling very oddly. Stopping and starting very quickly (almost like a clunk). Heard thumping noise and could actually feel it under passenger side front seat when placing hand on evaporater. It doesn’t seem to be cooling anymore either. Have no idea what’s up.

Will have to call local shop tomorrow. What a bummer.

 

Sorry to hear that your repair did not last. If your compressor was just short cycling I would guess low on refrigerant charge, but a knocking noise from the compressor is not good. Sounds like a mechanical failure of the compressor. Pressure readings when gauges are connected will help diagnose this. Once the system is open and if you find metal particles in lines all lines will need to be flushed, condenser and expansion valve replaced. Otherwise new compressor will fail again. AC work can unfortunately get expensive quickly if the job is not done correctly. Report back with your outcome, good luck.

 

Thanks. I don’t understand, because they said they evacuated it and tested it, and it was fine. It wasn’t making this clunking noise before the service. Wife took car to work this morning and it was fine, but yesterday I test drove it for awhile and was able to replicate the noise. Once I turned off A/C it stopped. I’m calling them this morning. Earliest I can get it there is 4pm est.

 

Could be that the a/c relay is starting to weaken...have them check that as well!

 

I will.

Another member here, @Steve244, had this issue and Honda did his freon service, plus they changed the 4 prong relay: 39794-SDA-A05 and the Honda AC Dual Pressure Switch: 80440-SS0-901.

I know that 4 prong relay has been an issue, when searching the forum. Thank you so much for your suggestion!

 

I don't know why, but I prefer to think Honda replaced parts unnecessarily; maybe I was wrong. I don't think they tested the switch/sensor or relay, just replaced them because they were prone to failure and the added cost was low (under $150).

The pressure switch requires evacuating the system and recharging, so best you take it back to the original mechanic.

 

Thanks, Steve. Going to take it back to original mechanic this afternoon. Hoping the compressor wasn’t thrashed.

 

Its funny y'all mention relay failures. I just spent $115 on diagnosis, relay replacement and refrigerant fill/check on mine. I was convinced it was a dead compressor, turned out to be a dead relay. 10 years of cycling and that's all that dies. I'm astounded...

 

I failed to mention the AC relay earlier, that was a good suggestion. I replaced mine about 3 years ago along with the vacuum and recharge work. OEM relay was about $20 from Amazon. I did not test it at that time, these are prone to fail over time and relatively cheap and easy to replace. Still cooling good today.

 

A good news update. The Fit is blowing cold air again, without that loud thumping sound. Firstly the mechanic said nothing wrong with relays and such. System was still fully charged and compressor was fine. Everything was good, so that’s a plus. He did hear the thumping noise, thankfully. He said it was evaporator expansion valve sticking that was making the thump sound.

He evacuated and charged the system again. After this he was unable to replicate the thump sound again. I took it for extended drive, it was cold and compressor cycled fine and I couldn’t replicate the thump as well. Hopefully this got any remaining debris out of lines. Crossing my fingers... once again.

 

Hopefully you are good to go and no more problems. No ac in the south this time of year is pretty miserable. Thanks for the update.

 

Thanks @fit09 for checking up and yes the heat here in SC is kicking up a notch. I appreciate all your helpful posts and all the helpful posts by the other forum members. We’ll be riding around a bit more later today, so this should be another good test. Hopefully no issues and no more bad news updates.

 

I may have missed it but did the A/C tech check for a leak (UV light)?

 

Hi spike55_bmw,

He didn’t. He told me it held vacuum and if there was a leak, it was extremely slow? Said if it happened again, he could check then. When he checked it after the last incident, it still had all its refrigerant from the prior service.

We’ve driven the car extensively, including this morning, for 3 days and everything is working fine. No odd noises and blowing cold air. I wonder if there was still some debris or moisture left in the system, and the second service finally cleared it out? Going to trust the work for now and see how it goes.

 

Harbor Freight has a small but strong UV flashlight for $8. I got one for other purposes but you could check your system in a dark garage / at night.

 

When we travel again in the next month or two and have access to garage, I will try that.

I really appreciate the tip!

 

The dreaded freeze up happened to me today. 1.5-1.75 hr trip on the turnpike towards Philadelphia in 90 deg F weather and it felt like 80% relative humidity.

I have a dial type kitchen thermometer clipped into one of the air vents ('11 Sport AT), and about 1 hr into the trip the temp started to increase from ~40 deg F little by little up to 75-85 deg F. Also noticed that the fan wasn't blowing out any air although still making noise. When I stopped at the Phila end, left the engine run and the air discharge started to increase and get cooler over time, along with lots of condensate running out from beneath the car.

Hours later on trip home, about an hr into the trip same thing happened. Once home, I looked under the hood and saw that the low pressure A/C line had a thick coating of ice. Again, I left the engine running, let it sit in the driveway of our one erstwhile neighbors. It also rained, so 'the wet' is not all from the condensate coming out the of car but it was draining for a while. Part way through the thawing process, the fan slowly began to move air through the system and out the vents and then the air temps started to decrease.

So, this never happened before but I never drove that long in high humidity. Although I'm not an automotive HVAC tech, it seems to me that ice slowly forms on the evaporator / heat exchanger, in the dash, to the point that less and less air is getting moved even though the fan is making normal sounds (FITs aren't that quiet so hard to hear). As less air is treated / cooled, the air temp increases inside the car. Once it is allowed to sit still with or without the engine running, the hot engine / cabin heated by the Sun, melts the ice and things go back to normal.

To me, it doesn't seem like it is a relay problem or low Freon pressure. The in-dash evaporator / heat exchanger is freezing up under high humidity conditions after an hour of non-stop (70 mph) driving. Never had a problem when doing local driving since any ice buildup melts while the car sits between errands. Seems like 'stuck in traffic' might also melt any ice build up. Just odd that it never happened before.

That's my story.