I have a 2013 Jetta with air conditioning not working very well. But I am not sure if it is really defective. For the last few days we have had temperatures in the nineties. My car air conditioning works for awhile but does not keep blowing cool air even in ninety degree weather with the air conditioning turned up to full. I have had the coolant filled and the last time I took it in to have it checked, he said it was full. But the problem persists. Do these units have some kind of thermostat on the compressor that can malfunction and be repaired?
The vehicle needs to be taken in so a set of manifold gauges can be connected to determine the state of charge of the system.
There are a number of things that can cause an A/C to provide insufficient cooling.
These problems are near impossible to diagnose without car in hand. What needs to be known are 3 things.
Static system pressure; meaning low and high side should be the same with the engine and A/C off.
The low and high side pressures at idle.
The low and high side pressures at elevated RPMs.
Without knowing those numbers it’s basically throwing mud at the wall and hoping something sticks.
It is common for cars to reach a certain age and refrigerant loss will occur with that age. Auto systems are not like home central units as the latter is pretty much metal lines soldered together. With autos, it’s rubber hoses, seals, O-rings, and so on.