2017 Nissan Quest A/C issue

[mjk1967]

Hello.
It's been a long time since I've had an AC issue, so I'll try to fill you in.

Today -- ungodly hot - real feel 97. I'm sure the Southerners will laugh. Work out of my van, so I'm in it a good portion of the day. Yesterday, similar temps, my AC was working completely normally -- I usually have it at 70.

Today, its barely blowing cool air at 63. Compressor is kicking on, I do not have HVAC gauges. Typically a leak (from past old cars) doesn't seem to show up this rapidly. Obviously, something is going on -- just have not seen this happen this rapidly.

Any thoughts? Is the system bogging down due to our conditions, or more likely, I am losing refrigerant.

Thanks...

 

[michaelluscher]

Cabin filter clean?
Condenser unobstructed/fans working on all speeds?
Ambient air temp reading on dash within realm of reality?

Compressor short cycling?
Rear A/C functional?

If simple checks get you no where, time to either get a gauge set or have someone with an appropriate machine evacuate and weigh in the appropriate charge
Or, you could try topping off using A/C gauge readings as a guide
IME, doing that on Nissan variable displacement compressors is difficult

Some workflows if you're interested
https://lemon-manuals.la/Nissan-Dat... Air Conditioning System/Diagnosis Procedure/
https://lemon-manuals.la/Nissan-Dat.../Refrigeration System Symptoms/Symptom Table/

 

[mjk1967]

Cabin filter clean?
Condenser unobstructed/fans working on all speeds?
Ambient air temp reading on dash within realm of reality?

Compressor short cycling?
Rear A/C functional?

If simple checks get you no where, time to either get a gauge set or have someone with an appropriate machine evacuate and weigh in the appropriate charge
Or, you could try topping off using A/C gauge readings as a guide
IME, doing that on Nissan variable displacement compressors is difficult

Some workflows if you're interested
https://lemon-manuals.la/Nissan-Datsun/2017/Quest SL/Repair and Diagnosis/Heating, Ventilation & A/C (HVAC)/HVAC Control Systems/Heater & Air Conditioning Control System (Automatic Air Conditioning)/Symptom Diagnosis/Insufficient Cooling/Front Automatic Air Conditioning System/Diagnosis Procedure/
https://lemon-manuals.la/Nissan-Datsun/2017/Quest SL/Repair and Diagnosis/Heating, Ventilation & A/C (HVAC)/HVAC Control Systems/Heater & Air Conditioning System/Symptom Diagnosis/Refrigeration System Symptoms/Symptom Table/

Cabin filter clean, rear a/c working up until Sunday. Don't have evidence of any short-cycling..
I took the easy way off, and dumped some refrigerant in. It's working, if it gets me through the summer, I was planning on trading in next spring/summer. Else, it will go to my mechanic.

 

[JavierH19]

Did you hear any hissing coming out of the Schrader valves when you took the caps off.