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Volkswagen Jetta A/C Does Not Blow Cold Air
Volkswagen Jetta A/C Doesn't Blow Cold Air
A busted A/C on a Volkswagen Jetta is the problem of the day. We just solved an A/C problem on a Chevy Equinox, so let's see what we can find on the Volkswagen Jetta GLS.
This is the vehicle:
VEHICLE: 2003 Volkswagen Jetta GLS 1.8L, L4, MFI, DOHC, VIN -, Eng Desg AWP
The Volkswagen Jetta is a great car and with a little bit of maintenance will last you a long time. But there are some issues with the A/C. Since this is an import service center, we see a lot of different makes and models of the Volkswagen and A/C issues seem to be the #1 complaint from Volkswagen owners. So, let's get to the original complaint:
Customer Concern: The A/C system does not blow cold air. There is a vibration and/or noise in the A/C lines that can be felt inside the passenger compartment of the vehicle.
And once again we will start with some basic tests to see if we can find any obvious problems.
1. Install a gauge set on the Jetta and look at what the gauges say. Some possible examples are:
A. If the high side pressure is high and the low side pressure is high, that would indicate an A/C compressor overcharge situation (this could be refrigerant or oil overcharge).
B. If the high side pressure is high and the low side pressure is low, this could indicate that the a/c compressor is stuck at its maximum displacement or that there is an other-than-specified restriction in the system. Signs of frost on the lines indicate the point of restriction.
Some simple things to check when your a/c fails
2. Flush the A/C system with nitrogen or refrigerant. This requires using a "dummy" restrictor that is a straight opening at the flush point. DO NOT under any circumstances use air to flush or blow out the lines. This will introduce moisture to the system that will be difficult to get rid of.
Flushing the A/C ensures that all the refrigerant and oil is out of the system so that when the charge procedure is performed, one can be as accurate as possible about the amount of refrigerant and oil in the system.
3. Inspect the restrictor for signs of damage. Look to see if the restrictor is completely plugged. On expansion-type restrictors, look to see if anything is blocking the movement of the valve.
4. Inspect the A/C lines for evidence of desiccant coming apart. This will typically look like a gray sludge paste (think valve-lapping compound). If the desiccant has come apart, flush the A/C system. The desiccant can plug up the restrictor or cause damage to the compressor.
5. When replacing the Volkswagen Jetta's compressor it is recommend to drain all the oil out of the compressor (if pre-filled) and measure the amount of oil. This way, the actual amount of oil in the A/C system can be known and accounted for.
After running these tests on the Volkswagen Jetta A/C, here are the conclusions that we came to:
Potential Causes: Incorrect Refrigerant Charge: Overfilled
Incorrect A/C Refrigerant Oil Charge: Overfilled
Failed Air Conditioning (A/C) Drier/Filter: Desiccant came apart
Plugged A/C Restriction: Either the expansion valve or the fixed orifice tube
Sticking A/C Compressor: Variable displacement compressor stuck in the maximum displacement position
And this was our confirmed fix:
Confirmed Fix: Replaced Expansion Valve
Replaced Air Conditioning (A/C) Drier/Filter
Tech Tips: VW/Audi recommends replacing the drier unit along with the compressor. It may be worth consideration quoting out the restrictor (expansion valve or FOR depending on system) and a system flush to make sure that the system starts fresh and new and to reduce the chances of an overcharge situation