again a/c got me crazy

[jeepkiller]

o.k i am losing my mind ..new fan clutch new thermostat flushed rad. i can sit in driveway and have the air ice cold for hours on end but when i drive it loses it coolness after about 12 miles i know that because i work 14 miles from home and it does this every time at almost the exact same point in my drive. the freon looks good what else could it be....HELP ME PLEASE

 

[george_tlc]

... and if you pull over at 12 miles into your 14 miles and pop the hood is the compressor engaged and running, belt tightness adjusted? Does it cool down again if you sit there and let it idle for a bunch of minutes? Is your engine overheating (don't just believe the useless temp gauge unless you have modified it)?

cheers,
george.

 

[jeepkiller]

i have never pulled over to check if compressor is still going never thought of it considering i can let it idle in my drive for hours and it never shuts off and as far as overheating it dont seem to be ..what is that connector in front of the battery behind driverside headlite could that have anything to do with it...still learning the ins and outs of my 450

 

[george_tlc]

Well, you need to measure you actual coolant temp, the A/C system will shut down if the coolant is too hot (search the forum for actual numbers). Behind the headlight on the DS is the dryer and pressure switch stuff for the AC, at least on the 1FZ 80's given you say you have a lx450. OBD2 ready plugged in will give you coolant temp, it can be overheating as far as the AC system is concerned and the stock temp gauge won't even have moved...

AND... you REALLY SHOULD add some details in your signature area regarding your 80 so we know year/trim/any mods etc.

cheers,
george.

 

[jeepkiller]

i apoligize for that it is a 97 lx450 no engine mods only cosmetic except for the silicone hoses 137000 miles

 

[Tools R Us]

Need more info, what is running what is not. The A/C will turn off if the coolant temp reaches ~226F.

 

[jeepkiller]

if it is overheating as far as the a/c is concerned but not overheating as far as temperature wise on the truck what could be the problem like i said just getting to know the mechanical stuff on the lx what is obd2

 

[jeepkiller]

Need more info, what is running what is not. The A/C will turn off if the coolant temp reaches ~226F.

the truck will run at normal temp in idle and air will blow cold all day but as soon as i drive 12 miles it will lose coolness but temp stay the same right below half.. i got a fan clutch from autozone brand new thought it was that so i took it back and got a new one and it does the same autozone #2661

 

[Tools R Us]

If you're sure the motor isn't running hot, then it is likely the A/C. Does the interior fan keep running, just the output becomes warm? What are the charge pressure numbers, what is the high pressure number when it turns off? Can leave your location a secret, but it would help to know the conditions/ambient temp when this happens?

 

[jeepkiller]

If you're sure the motor isn't running hot, then it is likely the A/C. Does the interior fan keep running, just the output becomes warm? What are the charge pressure numbers, what is the high pressure number when it turns off? Can leave your location a secret, but it would help to know the conditions/ambient temp when this happens?

interior fan keeps running yes the output becomes warm dont know the pressure # i dont have any gauges and i am in florida and it was about 95 when this happened gonna see if i can find some one with gauges i just used the one on that a/c pro can to tell me when there was enough freon

 

[John McVicker]

As was suggested...and you've got to do this:

Next time it begins to blow only warm air, stop, pull over and see if your AC clutch is rotating, then let us know.

John

 

[jonheld]

You've already been told that the stock temperature gauge is inaccurate, so at this point you don't know if your engine is overheating.
There is an OBD2 port by the driver's left knee. You can purchase a $12 bluetooth OBD2 reader and download the TORQUE app and get a real temperature reading on your engine.
You're also using an aftermarket fan clutch which has been proven to be inferior to the OEM product.

The fact that you can sit at idle and have the AC blow cold and as soon as you start driving the AC stops, is SCREAMING engine temperature to me. At idle there is no load on the motor. You have a cooling system issue that you need to resolve.

 

[jeepkiller]

You've already been told that the stock temperature gauge is inaccurate, so at this point you don't know if your engine is overheating.
There is an OBD2 port by the driver's left knee. You can purchase a $12 bluetooth OBD2 reader and download the TORQUE app and get a real temperature reading on your engine.
You're also using an aftermarket fan clutch which has been proven to be inferior to the OEM product.

The fact that you can sit at idle and have the AC blow cold and as soon as you start driving the AC stops, is SCREAMING engine temperature to me. At idle there is no load on the motor. You have a cooling system issue that you need to resolve.

thank you for your imput that is kind of the answer i was waiting for just was not sure what an odb2 port was i will definitely give that a try as i stated never got into mechanics part of the lx just cosmetics still learning ...... thanks again

 

[jonheld]

thank you for your imput that is kind of the answer i was waiting for just was not sure what an odb2 port was i will definitely give that a try as i stated never got into mechanics part of the lx just cosmetics still learning ...... thanks again

The OBD2 port is in the fusebox by the driver's left knee. You will see the connector at the top. Have a look at the links below for the OBD2 adapter and the Android app. This combination is very powerful and will give you realtime measurements. Not sure if they make something similar for the iphone.

https://www.amazon.com/Scanner-Kitb...17&sr=1-4&keywords=obd2+bluetooth+for+android

Torque Pro (OBD 2 & Car) - Android Apps on Google Play

Once you've established what's going on as far as engine temps, you can move to the next step.

 

[FJ80HI]

The other thing it may be is the AC refrigerant expansion valve. The valve is located in the blower box behind the glove box. $30 part but a lot of work to replace. Need to vac the AC system of refrigerant. Remove the blower box and replace the expansion valve (and drier/filter). Then connect system and vac, and fill with refer. I did the job in a day with a vac pump I bought on line, as well as a set of AC gauges. Refer can be dangerous so best to fine a good, honest AC shop. I could not find such shop so did it myself. My ac would run fine for the firs 10 miles, then start blowing warm air (ac compressor on and rig not overheating). Sometimes, after the vehicle was parked with engine off, or after turning ac off while driving, when I turned the ac on it would run for a few minutes then get warm. So what was happening is the expansion valve was getting clogged, when the ac was off, it would unclogged and ac would work for a while, until the valve got clogged again. One ac shop told me the compressor needed to be replaced, but they said nothing about the expansion valve. If you hook up gages you can diagnose a clogged expansion valve- basically looking for very high pressure upstream of valve and very low pressure downsteam.

 

[jeepkiller]

Thanks guys gonna get after it this weekend

 

[flintknapper]

As already mentioned....IF the blower fan is still running and the vent temp suddenly goes warm, chances are your coolant temp has exceeded 226° F and the A/C will shut off. Your dash temp gauge is less than 'worthless' for monitoring engine temp. You will need to find some way to accurately measure the coolant temp.

Odds are good you have a cooling problem. The fan clutch (if not OEM) is almost certainly lacking.

IF it turns out your engine/coolant temps are not the cause, then it is possible you have blockage in the A/C system or moisture that freezes up. A set of gauges would allow you to take a reading and might tell us something.

I put a scangauge in my L/C so I can constantly monitor my temperature (real time). Didn't see any need to do the temp gauge mod.

I live in Deep East Texas where it is sweltering HOT and HUMID four months out of the year. I can't think that Florida would be much better. You need to have your cooling system working top notch all the time. The 80 series L/C....LX450 are bad about building up underhood temps IMO. You have GOT to have a good fan clutch. I even did the fluid mod on mine. Really helps.

Good luck to you, let us know.

Flint.

 

[Nonobeez]

Having the same issue described in post #15... low side very low and high side ok or high. I was suspecting too much oil in the system but bad expansion valve very possible... definitely an obstruction on the low side

 

[inkpot]

First order of business for most of us is get the fan clutch sorted out/upgraded. Get a new blue one from Rock Auto or Amazon. Replace the silicone fluid with 20-30,000 CST silicone and then go from there. Search on this forum for lots of info on this. John

 

[Rifleman]

Along with what all the other members are telling you to check, I'd also check out the condenser core. When i did the cooling system on my truck, what i found was after 22 years of use my trucks condenser was plugged full of bugs, leaves, and other crap. I spent a few hours using a small nylon wire tie to clean between the fins to remove all that crap. So first off, you need to check to make sure that you don't have any bent fins, if you do they can be combed out. Next, look to make sure that your core is not plugged with bugs, leaves and other crap, if it is you'll need to clean it. If the core has any oil on it, you need to clean that off too, because oil attracts dirt, and dirt will plug your core. Last, you can pick up a can of spray foam cleaner from an AC shop, use it to wash the condenser to finish your project. As a plus from doing all this work, you'll now be getting alot more air flowing through your radiator, and with these trucks, they can use all the cooling help they can get.