Posting this for a friend.

Last Thursday 2011 Honda Accord AC stopped cooling all of a sudden.

The service center found the system low on refrigerant, topped it up and ran some dye through the system. The friend used the car for a few more days before the AC stopped cooling again. The service center revisited it and determined that the evaporator had sprung a leak.

So they replaced the evaporator, receiver and expansion valve and refilled the system with refrigerant.


The AC system works for some time before giving up. According to the owner it cycles on and off at random, less likely to work at night.

The low pressure side was encased in ice when he looked under the hood.

Iced up low pressure side


What could explain these symptoms?

  • It is low on refrigerant. Have the shop that replaced all those parts find and fix the leak.
    – agentp
    Commented Aug 28, 2017 at 17:28
  • Low refrigerant is one of my prime suspects as well. I'm told that the shop has had a look at it but they're perplexed as to what's happening. In case the amount of refrigerant turns out to be ok, would anything else explain these symptoms? I'm inclined to think a bad expansion valve could do this as well
    – Zaid
    Commented Aug 28, 2017 at 17:50
  • 2
    It is possible that the shop did not get the evaporator temperature probe installed properly. this would cause the system to keep running past the freezing point. Commented Aug 28, 2017 at 18:39
  • It is normal for the suction ( gas) line to be covered with frost ( with AC on) , depending on the weather conditions. Commented Feb 22, 2018 at 0:49

2 Answers 2


Try changing the cabin air filter. A clogged filter will restrict the flow of air around the evaporator core causing it to freeze up. This would probably explain why it cycles on and off at random times maybe due to a partial core defrost then it kicks and stops again when the core freezes up. At night time when the ambient temperature drops could also be a factor as well. After changing the cabin filter run the heat up to max to melt the ice. If you see a heck of a lot gushing out of the drain tube then voila-I was right :)

  • And if the drain tube is blocked, check your carpet mats for being soaking
    – Caius Jard
    Commented Aug 29, 2017 at 7:33
  • Drain pipe is on the firewall facing the engine and will be thawed by the exhaust manifold heat. It doesn't drain inside the vehicle and therefore would not soak the carpets in any way.
    – Old_Fossil
    Commented Aug 29, 2017 at 17:00
  • I meant if it was blocked with mould/crap/dust/slime rather than ice..
    – Caius Jard
    Commented Aug 29, 2017 at 19:03
  • Either way it wouldn't drench your carpet. If the drain is blocked use a thick pipe cleaner and poke a hole through the crud... One thing that like to hide there are spiders..I guess they get thirsty too.
    – Old_Fossil
    Commented Aug 30, 2017 at 6:13
  • Where will the condensate go if it cannot escape down the drain hole?
    – Caius Jard
    Commented Aug 30, 2017 at 6:22

As mentioned by others, the primary reason for Icing are as follows:

  1. Dust and other debris clogging the HVAC system.
  2. Leaks in the system causing it to have less amount of coolant or gas.
  3. Issues with the thermostat/temperature regulator.

and for the Air condition cycling on and off the primary reason is lack of coolant/gas and in some rare cases, overfilling.

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