jgrooms

I purchased a 1997 ES300 in July and in August I had the dash replaced by the Lexus service dept. Since that time I have noticed an annoying hissing sound whenever the a/c is running. It is loud enough to be heard over the radio at a normal volume. It happens every minute or two and lasts for about 10 seconds.

I brought it to the attention of the service dept. and they said it was normal. I have never heard this type of sound from any other car that I have owned.

My question: do any ES owners out there notice a hissing when their a/c is running?

Thanks

ramsee1

no. i mean you can hear the pressure build if you hit the ac on high, but that's it. i don't think that is "normal". But I've never known a dealer to turn down money, so that is just as odd.

Steve Barnes

I also get the hissing sound... the A/C comes on intermitantly and every time it hisses... but not that loud though. I had it re-gassed six months ago and now the gas is gone. When i first had it gassed it did not hiss.

I would expect your AC gas is low. Thats what is making it hiss.

My 92 model runs on the old type gas.. not sure of the name of the old type gas but apparently it is illegal to use it here now as it has something to do with the enviroment laws.

The old type gas used to rot the rubber seals apprently. I am going to have a conversion done next spring so i can use the newer gas and also fix the leak i have in the A/C

The funny thing was that the air conditioning specialists tested the AC system for leaks and there were no leaks found so i guess the seals where re-openedwhen it was gassed up.

benm024

I have this same problem except it is on a brand new '02 IS300. Did you ever find a fix for this very annoying hissing sound?

Thanks,

Ben

jgrooms

I brought my 97 ES300 to my dealer twice for this problem. Both times a mechanic rode with me while I pointed out the hissing sound. Both times they said it was caused by the expansion valve and that it was normal. What finally convinced me though was when I was given a 2001 RX300 as a loaner and it made the same noise.

It appears that this is an imperfection Lexus still needs to pursue.

benm024

I think I know something that might quite the problem down a little.

when I got the car back from the dealer yesterday he said that the noise was greatly reduced and he could not even here it anymore, but he was not sure how he did it. He said it went away after he completly flushed the freon and refilled it. Apparently it was 2/10ths below full when I brought it in. He says he has no clue why just topping this off would fix the problem.

It seems after a day that it is 90% better then when I brought it in. Now I heard it for about a minute this morning but it was alot quiter than before. Ever since this morning I have not heard it at all. I got to believe a full load of freon is what did the trick.

If you are still having the problem suggest to your dealer to check the freon and fill it up completly full. That should at least make it occur less and quite it down a little.

Anyway props to Dave Mungenast Lexus of St. Louis for taking the time to try things even if they were not sure it was going to fix anything. Plaza Lexus (where I bought the car from) was not willing to put forth this effort.

-Ben

supwithyou

BTW for all you guys with the old A/C Refrigerent R34, Discount Auto parts has a conversion kit for like $40. I did it myself and converted to the new cheaper gas, and it has a self-leak fixing gas. It is very easy and comes with simple instructions on how to convert it. DONT PAY $600 dealer costs for a 20 minute job! Just thought u all would like to kno that.

Steve Barnes

thats interesting... i thought my local Air Con Gas dealer was cheap for the conversion. They said they would convert the air con to the new type gas for £150 ($200) which i thought was cheap... but $40 is even cheaper.. Hooray

Now i just have to find the conversion kit over here. Any idea what consists in this conversion kit? I want to go and hunt for the kit... Is the kit universal?

thanks

Tecknician

The conversion itself is not expensive, its the extraction/recycling of the old freon that costs a pretty penny.

If you are doing it yourself at home and have old refrigerant in your lines please for gods sake where a respirator if you insist of releasing it into the air (illegal).

Stay safe