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I have a Honda Odyssey 2019. The a/c blows ice cold… as long as I am actively driving. Once I come to a stop and begin idling, the air is no longer cold. Of note, I can get the air to be a bit cooler if I rev my engine while idling… but it’s only coolER, definitely not ice cold like it is when actively driving.

Dealership doesn’t have a clue what could be wrong and wants $500+ to do an evac and recharge w/ UV dye to look for leaks. I guess this is their starting point in their diagnostic process.

I am very aware that my knowledge base on engines and a/cs, etc is extremely limited, but I am a very logical thinker and it just seems that gathering more data first is warranted… like measuring the ??coolant?? ??level?? (I don’t know if I’m using correct terms) and comparing current measurements to what should be expected might reduce some variables when it comes to narrowing down potential causes. Especially considering the issue seems (to me, at least) to be fairly specific (compared to just a vague “air not cold” complaint).

Any guidance, advice, knowledge, recommendations, etc etc is greatly appreciated! Thank you for your time! :) :)

VioletHeart
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3 Answers3

14

The AC often relies on the the electric fan near the radiator at the front of the engine bay running to cool the refrigerant. If the fan isn’t running while stationary there won’t be sufficient air flow to keep the AC working correctly. Do you ever hear this fan running?

Please be careful with your fingers when working around this area, because the fan could switch on unexpectedly, even when the engine is off.

Community
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HandyHowie
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You are right to ask questions about this. The very first thing a mechanic should do is a pressure check of the AC system, if the pressure is low then it makes sense to look for leaks. If the pressure is good then there's no leak and an evac-refill is a waste of your money.

In any case $500 for an evac and refill on your AC system sounds like a massive overcharge to me, I'd expect to pay half that at most. I suggest you take it to a reputable independent mechanic instead.

GdD
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Poor AC performance when idling could be caused by the compressor not performing well at low RPM, or by heat buildup around the condensor due to lack of air flow when the vehicle is not moving. You can roughly distinguish these two conditions by revving the engine in park/neutral and seeing if the air gets cooler.

If it does get cooler, you have a problem with cooling performance which may be caused by insufficient charge of refrigerant (possibly due to a leak) but might also have other causes.

If it does not get cooler, you have a problem shedding heat from the condenser. This could be due to a failing fan, the fan not switching on when it should, severe dirt on the condenser fins, general engine compartment overheating possibly from poor engine cooling system performance, or a number of other things.

Before even considering spending money on evac and refill, you need to figure out if it's plausible that doing so could fix anything.

R.. GitHub STOP HELPING ICE
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