Air Conditioner Oil Slick on Windshield

lexus
oil
airconditioning
windshields

#1

In Florida. A/C runnning always. Grey oily film accumulates quickly on inside of windshield. Nobody can fix it or tell me what it’s from! I’ve already replaced the compressor. Am in the car breathing this stuff all the time! I’m not dead yet, but I’d like it to be stopped.


#2

Are you sure it’s not antifreeze from a leaking heater coil? Will a water-wet paper towel get any of it off?


#3

That’s probably not from the AC. Instead it’s outgassing from the vinyl in the car. This has been a problem with cars for decades, funny that nobody has solved this yet. The only thing you can do is keep cleaning the glass.


#4

Age and mileage of your ES 350? Are you losing coolant? A leaking heater core will put a greasy film on the windshield. If it’s coolant, breathing it is hazardous.

If the AC system is leaking the compressor will eventually shut down when the refrigerant level got low enough. How long have you had this problem?


#5

The best way o clear it thus far is rubbing it off with a large cotton towel. Wet does not help.


#6

Is there ever a sweet smell? If so, that’s probably coolant.

Do you use interior protectant products like Armor All? Those will put a film on the windows, especially in hot weather.


#7

'94 180,000 miles. Just had the compressor replaced. Slick was occurring before that and continues. Had hoped it might stop with the replacement, but it didn’t. Condition has worsened over a four year period


#8

I’d guess it’s not vinyl gassing because it accumulates much too quickly.


#9

Replacing the compressor would have no effect. If it’s not antifreeze (still my first guess), and it is oil from the air conditioner, the only way it would get on your windshield is if there is a leak in the evaporator coil. If it’s a big enough leak to cause this rapid of a problem, an AC shop should be able to detect it with a leak finder.


#10

I think perhaps you aren’t understanding here. They are asking about coolant, as in the anti-freeze in the radiator, not the R-134 in the air-conditioner.
Why was the compressor replaced? There is no way for it to be connected to a leak inside the cabin. Also, an R-134 leak would not fog the windows. You are looking at the wrong system for the problem.


#11

Thanks so much, folks. I really do know that we are speaking of two different ?coolants? here: the engine coolant in the radiator, and the refrigerant in the A/C system. I am not sure when the change from R-12 to R-134 happened or which is in the car. Have never had to have it topped up.
The compressor simply failed from old age I was told. It stopped turning, but the cooling did not diminish prior to its failure. Am I right in thinking that cooling would stop suddenly if there were an R-? leak in advance of a compressor failure that would follow as a result? I did not know that A/C oil suspended in the R-? had no color (grayish) so thanks for that. I?ll ask about the heater core leak possibility (although I should think my mechanic should have had some idea about that,) and have the evaporator coil checked for a leak. Thanks again.