AC diagnosing looking for ideas

Ok so my ac blows around 60 degrees out the vents at best, which from what I understand it should blow around 40-50 degrees.

Ambient temp with gauges hooked up was around 95 degrees, which should produce a reading of
low: 50-55, high: 275-300.

The actual gauge readings were like this:
low: 38-53, high: 300-325.
So the low side is low, and the high side is high.

From the limited info I could find online, it says that there could be blockage in the system. Any ideas what could be the culprit, or what else I could test to help narrow it down?

 

Do you have a proper charge? Is your fan pulling air properly?

 

Fan is blowing plenty of air, not sure if it is charged properly. The last two years in a row I have taken it in to be recharged and really they didn't add much. There is UV dye in the system but I don't see leaks anywhere.

 

your system stiil has over 300psi when compressor is on, since the last time you serviced it, so doent sound like you have any leaks.
I would say your pressure are too high, likely still have air and moisture in your system or even overfilled with oil.
It is a closed system, its doesnt you leaks. If you had to get it recharged, that mean something had failure, like a o-ring or compressor failure or accidents condenser leak.
You could check the metal pipe in the engine bay. if the high side small pipe is too Hot to touch, and if the low side bigger pipe is cold with condensation.
I say you culprit is the technician that last worked on you a/c.
You should bring it to the dealer an get it properly serviced, at least dealer would have proper equipment, and at least they should be putting the correct parts in you truck. Ask them to change out the dryer element, everytime a/c needs service.
Saving money going somewhere else end up costing more, do it right one time and i should be good enough.
Summer in Socal with a not optimal a/c with ??? sucks..
And maybe before you do anything, try cleaning you condenser first, if you offroad.

 

Does it get cooler at highway speed?

 

Toyota dealer is the ones who recharged it both times. I would like to get this fixed under warranty, but it seems my dealer cannot find their ass with both hands so I am taking matters into my own hands to get it fixed the right way. Or if I can diagnose what is causing this issue, go to the toyota dealer and speak with the head tech to show him my findings and see if he can specifically work on my truck and not one of the lower level techs who mostly do oil changes all day. Not saying they are all bed, but wisdom comes with time if you know what I mean.

Edit: I also just cleaned the condenser last weekend with nu-brite. Nasty stuff but it cleaned it up really nice.

At idle it blows between 70-80 F depending on conditions, sometimes it blows at 62 idle also. Just depends on where the truck is and if it’s heatsoaked already.
Coldest I have seen it blow is 60 F. Wether that is from me reving 2k rpms while stopped, or going down the highway at 70 mph.

 

I would start with a proper evacuate and recharge and make sure the fan clutch is operating properly. Just because it spins doesn’t mean it’s pulling the proper amount of air.

 

I can feel the air being pulled through the condenser at idle, but I have a feeling a lot of the air may be coming in from the sides of my of my radiator instead of going through the condenser. Just a guess judging by how much air is getting blown around the engine bay compared to what I can feel going through the radiators. I plan on having a friend call the guy he knows at toyota to see if he can get my truck to someone who has a better idea about ac to look at it. If that doesn’t pan out I am going to test making some block off plates that will force the air through the condenser before the radiator. Just to see if it improves at all.

After that I will take it to a shop to have it evac’d out, then I will bring it home, change any parts if I need to, and pull a vacuum then charge the system.

 

^^^^ this. The thing is inadequate cooling complaints often appear along with statements that someone had done a DIY charge or had something added recently such as oil and another charge etc. and one simply does not know how much of what is in the system. The Tacoma system has a very narrow window of charge where proper cooling occurs and if it is either slightly overcharged or slightly undercharged it does not function very well and further experimentation can lead to damage.

IMHO trying to narrow things down using gauges is an art best left for the experienced as the external conditions have to be precisely met for monitoring temp, humidity, fan position, doors open, in shade, and so forth.

If this were mine, I would have it evacuated and the system put under a deep vacuum to make sure it is dried out. Then recharge by exact weight and weight only according to the label underhood.

 

Yes I understand the concerns, which is why I originally had toyota look at it. Their machine adds oil with the r134 which seems backwards to me because they did not replace any parts, so there should have still been plenty of oil in the system. I don’t know if their machine reads the mix of oil/r134 that came out when it evacuated the system since the paper just said:
Evac X lbs r134,
Added X lbs r134, Y lbs oil.

It seems both times I have gone to the dealer the techs didn’t bother diaging anything and instead chose to just evac and replace.

As far as anything else being put in the system I do not know, I purchased the truck used at 47,500 miles in the winter when I was not really using the ac much. Summer time is when these issues started arising. My friend is an auto/ marine tech so I may bring him a case of beer and see if he can “fix it” since I know he has done good ac work before.

 

My AC is also not working, blowing air and that’s it. After some diy trouble shooting, like check fuses and clutch relay I did notice a little compressor oil I assume, right at the high side sensor switch. It’s a very good chance it’s leaking at that o ring and the pressure switch is doing it’s job by shutting down the compressor when the r134a is low. I now have an apt. wed. at a independent shop. I want it done right.

Just to buy the manifold gauges, vacuum pump,scale, R134a, not to mention the parts and time and possibly my diagnosis would be wrong, I opted for a pro. But I feel I’m pretty well educated on the subject now. I also like the fact that the place has an automated machine that recovers not only the r134a but the pag oil. That’s one thing a diy never knows unless he is also replacing the condenser.

To much oil is also a no no. So if you have a leak and your replacing r134a your just guessing, unless you can extract it and replace it .


https://www.youtube.com/watch?v=IjLfyXCBw1k

 

I hear you and that is why I suppose so many of us simply do not trust the dealerships and seek to get the job done properly by learning things ourselves. Hats off to the good dealership techs, you know who you are, but the incompetent ones drove me to tackling many of the hard core issues myself.
I do not know anything about the machine Toy uses so its hard to comment about but I'm sort of wondering just how much oil you got in there? Oil takes up space that is supposed to be used for refrigerant and can drive the system pressure so high that a hose may burst. The FSM tells us approximately how much oil is retained in the major components and that is what I use for estimating, along with balancing oil with a compressor.
Also consider that a lot of DIYers end up putting a slug or many slugs of air into the system through the hoses and the gauges. Same problem, the air drives pressures high and does not cool.

 

After reading some of the FSM I think there may be air in my lines right now. The low pressure line is incredibly hot to the touch, I can only hold my finger there for a second or so. I am going to take it to Toyota one more time, and if they cannot get this thing blowing ice cold I will just have my friend charge the damn thing.

 

You sure it's the low side? The low side is the bigger line.

 

Yes, the High side is the one with the H marked on the cap inbetween the grill and radiator support, I touched the one with the other smaller cap.

 

@Murphinator
Let's do a quick check here.
The small diameter line going thru the firewall is the high pressure one coming from the condenser at the front.
The larger of the two lines from the firewall is the low pressure or suction line from the evaporator under the dash leading back to the compressor.
With the engine warmed up and the A/C going for a few minutes, you said one of the lines (I assume you really mean the smaller high pressure line) got real hot.
How about the other line, the larger one, coming out of the firewall, is it frosting up, cool, cold, barely cold, or what as near the firewall as possible but touching the alum tube.

 

Dont need to think about it anymore, just evacuate and charge it correctly. dont even worry if that is extra oil in there or not.
If after that it still not blow cold air than you can start your diagnostic.
You have pressure, your pressure sensors are working, and your compressor is kicks in and building pressure. Your system still holds pressure, should be no leaks.
What i would do is, go to oreilly's and rent a ac pressure gauge and a vacuum pump.
Buy 3 can of r134 and a charging hose with gauge. Buy a dryer element if you think you can change it out without make a new leak. if not, just pass on the dryer part for now.
Get a kitchen scale.
After you get all the tool and parts, i would just take you less than an hour.
Now you have a gauge, install to the low side with the truck off, sees what it reads. should be almost same as the ambient temperature.
After you find a way to evacuate and recover the system, install the gauges and vacuum pump. vacuum for 30min and close the valve and shut it off, and check if it hold vacuum for 5mins.
If it does then, go ahead a charge it with the r134.
But the very important part is what taco09 said, charge it by the exact weight to what it says under your hood. but you still have a +/- an oz or two of tolerance.
Use the kitchen scale and weight your cans of r134. (example, 12oz can with the can might comes out 16oz, so the can is 4oz. and 12oz of r134.)
see how much r134 your truck needs.
For example if its needs 30oz. Use the first can and put 6oz in the truck, disconnect from the charging hose, put that can aside.
now empty the other two cans all into the truck. you will get the total of 30oz.
Your charging hose have a gauge and its should read around 25psi to 40psi
now see how the compressor is running, and if the low pressure hose the bigger one is cold to touch.
If it colder than before, than just leave it and dont do anything else.
Don't put the long, rental a/c gauge on the truck and try to reading the pressure. If you try to do that you might suck up the air in those long hose into you system.
And if its not blowing cold air and you need to diagnose, than vacuum out the a/c gauge with the vacuum pump first. after you finish the diagnostic, open the low side and let the r134 back into the truck.

 

I am certain I was touching the low pressure side, it was the one we hooked the blue gauge to yesterday. Now I was not touching it where it comes out of the firewall, but near the condenser. And I was touching it after I drove home from work.

 

Huh, that's not right. I don't think I can internet help you.