Air conditioning working intermittently (1 Viewer)

[Razor One]

I have this issue on my '97 lx 450 with my air conditioning. It only works in cooler weather, or when I'm flying down the highway. When I'm stopped or when it's really hot outside, my AC doesn't work. I just replaced the fan clutch a few weeks ago, and I've already adjusted the hot water valve. My AC blows cold, just not when it's hot outside. It's like it's getting lazy.

Does that sound like a failing AC compressor, or maybe the system just needs a recharge?

 

[thedoughboy]

Can you see any green fluid in the peep hole next to the battery? If not, it sounds like a leak test should be performed. Low AC refrigerant can work in cool weather but fail in hot (weather). I chased this problem for a long time. If it's low it is leaking somewhere. Finding the leak is where the $ can come in. I was not up to this type of work so I took it to a reputable shop.

 

[Razor One]

Can you see any green fluid in the peep hole next to the battery? If not, it sounds like a leak test should be performed. Low AC refrigerant can work in cool weather but fail in hot (weather). I chased this problem for a long time. If it's low it is leaking somewhere. Finding the leak is where the $ can come in. I was not up to this type of work so I took it to a reputable shop.

I was afraid of this. I checked the refrigerant level and it's really low, but I looked around with a flashlight and couldn't tell where the leak was coming from. Any ideas or places to check?

 

[rubicondon53]

Good luck, I took mine to a very reputable shop, they dumped it, checked for leakage for over a half an hour, refilled it, and 3,000miles later, same results as you are describing.. I went to autozone, bought two cans of 134a and topped it off myself, and about every 3 to 4k miles I just top it off.... Sad part is, I wasted $95 paying a shop to do what I can do for 10 bucks.. I'll just keep topping it off myself.. I surmised from my experience that there is not a vacuum leak, but somehow there is a pressure leak...


...via IH8MUD app

 

[Rambrush]

Sounds like a possible bad compressor, Our Avalon would do great on the road but get slowed down in town with traffic and it would quit and the ac light blinked. Then shortly it would return. Tried the freon route but it was not to be. So hopefully you just have a bad "O" ring on the condensor

 

[Hornd]

Good luck, I took mine to a very reputable shop, they dumped it, checked for leakage for over a half an hour, refilled it, and 3,000miles later, same results as you are describing.. I went to autozone, bought two cans of 134a and topped it off myself, and about every 3 to 4k miles I just top it off.... Sad part is, I wasted $95 paying a shop to do what I can do for 10 bucks.. I'll just keep topping it off myself.. I surmised from my experience that there is not a vacuum leak, but somehow there is a pressure leak...


...via IH8MUD app

Maybe your unaware that PAG oil is Hyrdrophilic (water loving) and becomes acidic over time. With this mentality; why not just add oil instead of changing it? It's still running, so who can argue.
Pay the $75 and have it Evacuated, Checked for leaks, Receiver/Dryer changed and refilled then it will likely last forever (until compressor fails).
We are talking about less than one tank of gas in investment....

 

[akarilo]

Do you know what the actual temperature of the coolant is? The truck could be running hot and shutting the a/c off. The symptoms you described fit this scenario. I would add an accurate temp gauge for starters, as the stock gauge is worthless. I forget what temp the a/c cuts out, but there is a safety switch of some sort.

 

[CJF]

I checked the refrigerant level and it's really low

Checked how?

 

[CJF]

The truck could be running hot and shutting the a/c off.

This is absolutely the first thing to check and rule out.

 

[thedoughboy]

I was afraid of this. I checked the refrigerant level and it's really low, but I looked around with a flashlight and couldn't tell where the leak was coming from. Any ideas or places to check?

Like I said, I took it to a reputable shop. There are dozens of potential leak points. Mine ended up being the evaporator. Actually, twice now. The Denso replacement failed after 5 years.

 

[Tools R Us]

I was afraid of this. I checked the refrigerant level and it's really low, but I looked around with a flashlight and couldn't tell where the leak was coming from. Any ideas or places to check?

The leak could be anywhere, but the #1 leak point that we see is the manifold plate o-ring, where the lines connect to the compressor.

 

[Tools R Us]

Maybe your unaware that PAG oil is Hyrdrophilic (water loving) and becomes acidic over time. With this mentality; why not just add oil instead of changing it? It's still running, so who can argue.
Pay the $75 and have it Evacuated, Checked for leaks, Receiver/Dryer changed and refilled then it will likely last forever (until compressor fails).
We are talking about less than one tank of gas in investment....

Moisture gets in with air, so as long as the system hasn't been exposed to air, has some charge, there is no need to evacuate.

 

[Hornd]

I thought putting system under vacuum boils off all moisture and assures system is not hermetically sealed?

 

[rubicondon53]

Maybe your unaware that PAG oil is Hyrdrophilic (water loving) and becomes acidic over time. With this mentality; why not just add oil instead of changing it? It's still running, so who can argue.
Pay the $75 and have it Evacuated, Checked for leaks, Receiver/Dryer changed and refilled then it will likely last forever (until compressor fails).
We are talking about less than one tank of gas in investment....

It's obvious to me that you cannot read... Read my post again, word for word, and I dare you to repeat yourself, For if you read it, I did exactly as you recommend and lots of others, to no avail... A leak exists. I and my system can live with this very tiny leak... It was so tiny, that 1/2 hour on the machine detected no loss .. FNA,,, stop reading things between lines that just don't exist....


...via IH8MUD app

 

[Razor One]

Checked how?

I checked the peep hole, just like doughboy said. There is hardly any green fluid.

 

[Hornd]

It's obvious to me that you cannot read... Read my post again, word for word, and I dare you to repeat yourself, For if you read it, I did exactly as you recommend and lots of others, to no avail... A leak exists. I and my system can live with this very tiny leak... It was so tiny, that 1/2 hour on the machine detected no loss .. FNA,,, stop reading things between lines that just don't exist....


...via IH8MUD app

1/2 hr is no where near long enough. Mine sat 6 hrs at vacuum before they confirmed pressure was same and filled into Vacuum.
2nd if they put UV dye in refrigerant even a miniscule amount would show leak and most of system fittings are visible, only evaporator and expansion valve are not. It would take about 10 mins to check them all with a black light. They are known for a leak on the compressor. If they found no leak then I would proceed to fill.

Hope you are adding PAG oil every time you fill or in a short time PAG oil which will also cause a compressor failure. How do you know how much Refrigerant to add if you don't evacuate it....and the list goes on and on. Overfilling cuts performance as much as under-filling. Good Luck

 

[rubicondon53]

Friend, back in the early 90s I converted my Euro Sedan over to 134a myself.. The Car was an 89 and after I converted it drove it until 2004 and 220k miles, problem free. "Reputable" shop is sometimes an oxymoron.. Even those shops with great reputations will not do the proper job.. It would be really nice if, for 90 bucks, they would warrant their work.. Tell me there is no leak, then dammit there had better not be one or give me my money back... A/C shops don't do that, so, in the meantime I'll not be wasting another 95 bucks at another one, nor will I advise someone else to do the same.. A/C systems in cars,like plumbing or electrical work or HVAC in our homes is not rocket science.. When I have to add 134a more than once a season, then I might hire a " reputable " shop to fix it, if of course I could find one of these self professed reputable shops... I gave the OP a very easy and inexpensive way to diagnose his problem instead of hoping he can pick out a reputable shop to discover what he can discover on his own..


...via IH8MUD app

 

[1972FJ55]

I checked the peep hole, just like doughboy said. There is hardly any green fluid.

Realistically that's not a good way to check the refrigerant level. It would be better to hook up some gauges and see what pressures the system is producing. Better yet would be to have the refrigerant recovered so you know how much is in it.

 

[bajaphile]

Mine had an obvious leak coming from an o-ring on the side of the condenser...did the same thing you had mentioned.

Also just had my 95 M3 fixed by adding more coolant. Didn't see a leak, but its been fine since (+1yr).

Either put some UV dye in the system and look for leak, or have someone else do it.

 

[Razor One]

Bump!

Just got back from the Toyota dealership. After a diagnosis and a multi-point inspection, all it needed was a recharge, and a new condenser. Problem fixed and it's blowing ice cold, now!