Edes300

Hello I own a 2005 gx470 that I have owned since 2008. It currently has 141,000 miles on it and is in overall good condition except for on major thing. The AC system.

I have had a problem with poor ac performance for more than 5 years. When it was under warranty I would take it to the dealer and they would recharge the system and it would be ok for a year or two but now in the last 3 years it only lasts approximately 6 weeks.

last year I thought there was a leak in the rear evaporator using Dye. I replaced the evaporator and had to tap into the high and low pressure lines using a kit. There was so much corrosion I couldn’t disconnect the lines. When I was done the system held vacuum so I added 2 cans of refrigerant and I was ok for the rest of the summer and fall.

Now this spring just started to get warm and NO AC again. The first 2 pics enclosed are of my static pressures and the interior temp. Inside temp at this time was 90 once ac was turned on.


Static pressure

I then added some UV dye and one can of refrigerant and these are my numbers with engine running at 1500 rpm after 15 minutes


After one can added to system

After 2 weeks I fine no leaks with the dye except a light amount of dye from evaporator tube at end of fire wall. It’s in the dried condensation where it lands on the frame.

It looks to me like the leak is in the evaporator under the dash which is a huge job. Would like to take it to the dealer for their opinion but it’s closed due to Coronavirus.

I have done other complex repairs on this vehicle myself including secondary air injection system, plugs, center muffler, and rear shocks etc. may be a good time to replace my cracked up dash at the same time. Is there anything else I should check. I don’t have access to a Freon sniffer and the cheap one probably aren’t that useful anyway.

vwynn

iTrader: (4)

im no expert but GXs have a common problem where it leaks in the "expansion valve".

Edes300

Thanks for the reply. The expansion valve sits right next to the evaporator deep inside the dash I believe. No way to actually see it or change it without removing the dash.

I understand there is a upgraded expansion valve for hotter climate areas. I saw a tab about it somewhere but not sure if that means they are prone to failure.

Edes300

Corrosion present on bolt and expansion valve

Took it in to my local Lexus dealer to confirm my diagnosis. They agreed it’s in the evaporator core and possibly also the expansion valve. They quoted me a price of 6800 dollars if they put a new dash and 5800 dollars if they reinstalled my old dash but they advise me that I make get more cracks from the manipulation.

I declined the repair and to their credit they did not charge me for the diagnostic testing. They even gave me a discount on the parts. Approx 1100 dollars including a new dash.

so I’m almost done with this. I’m in the process of putting it all back together and here’s what I found.

campfire

WOW. I just charged mine, slow leak, one can got me through last summer. I hope it doesn't get as bad as yours!

Edes300

Mine was the same way a few years earlier but it had gotten so bad a recharge would only last about 6 weeks and there was a horrible smell presumably from the leaking PAG oil.