# Passat A/C freezing



## 75XJC (Oct 14, 2003)

Hi,
Our 2001 Passat V6 wagon has suffered from what appears to be freezing of the air conditioning evaporator since it was about six months old. The VW dealer has been unsuccessful in correcting the situation and claims no knowledge of any similar problem in other Passats.Has anyone on this forum had any similar experience and was a cure identified?
Symptoms: After approximately 45 minutes driving with the A/C on in hot weather, the air flow from the HVAC ducts dwindles to essentially no air flow. If the A/C is turned off (leaving temperature on coolest setting and leaving fan on) nothing much happens for two or three minutes, but then a small amount of cool air starts to flow, quickly becoming very cold and rapidly increasing to a very strong airflow, which slowly warms to match the outside air temperature. Frequently small bits of frosty ice spit out of the ventillation ducts as the airflow rises to the maximum flow. After several minutes of warm airflow, it is possible to turn the A/C back on and it will operate normally for another 45 minutes before repeating the cycle.
This can occur on warm days even without excessively high humidity (in New England). The dealer claimed to have attempted to blow the A/C drain line clear, but I suspect it was not done well if the mechanic really even tried to clear it. At least some condensate does appear under the car when the system is operaing properly.


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## TWOFOR1 (Apr 2, 2003)

*Re: Passat A/C freezing (75XJC)*

My first thought is that your system may have never been charged correctly to begin with. I'm no VW expert but I've owned them for over 30 years straight, but I do know air conditioning. Usually the condition you have mentioned, is either from improper charge of refrigerant (which VW recommends to recover the charge & then carefully measure in the exact amount required by VW for that specific vehicle), or improper air flow across the coils (could be either a dirty condenser or evaporator coils fins), or some sort of other blockage, i.e. even improper or malfunctioning air flap/diverters, etc. Any of these can cause the evaporator coil to frost over & as it thaws by using fan only, those are the bits ice that are being blown out. The cleaning of the evaporator drain line in my opinion, would only need to be considered, if the system, & when working correctly you make a hard turn & water drips inside, as on your feet from under the dash.
All of this said, I still would start by first recovering the refrigerant & throughly evacuating the system & then the proper refrigerant charge to the exact ounce.
I also welcome any comments in the event I may have missed something.
I hope this helps.


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