Auto Repair in Newport News

What happened to my A/C?

Hi Everyone!

Well, it is that time of year again! The temps have been low 70s for a couple of weeks, and then all of a sudden, WOW! We have our first 85 degree day. Everyone hops in that car that has been sitting in the sun for 8 hours, turns the fan all the way up, sets the A/C to mx and….sweats in the boiling hot air pouring from the dash because the A/C is not working.

So you need your A/C fixed; what should you, as a consumer know?

Ok, here are the basics. The A/C in your car works by compressing and expanding a gas called a refrigerant. commonly known by the R-12 (which is no longer in use) brand name Freon, this gas ABSORBS heat (kinetic) energy from the air as it is expanded inside the A/C system.

Your A/C system is complex enough to defy a layman’s description in this short blog. However, there are some basics you should know as a consumer to better understand A/C repairs.

  1. The vast majority of A/C repairs are leak repairs. The system has components that can fail under the very high pressures and temperatures in the system. Usually a leak is very minor, and you don’t notice it for a long period of time. Then from November untill March, you do not use your A/C at all. During this time, the leak is progressively decreasing the amount of refridgerant in the system. Then, in April, when you turn on the A/C there is no longer enough in the system for correct operation and your car shuts down the system to prevent damage.
  2. The coolant in the engine (antifreeze) has nothing to do with the A/C. The A/C is a stand alone system using a gas called refrigerant,  and is not affected by engine coolant level. The onbard computer will shut down the A/C on a car that is overheating, but at that point your concern is with the overheating problem, NOT the A/C.
  3.  Do NOT simply charge up your A/C periodically. The oil that lubricates and protects the expensive A/C components is carried in suspension (in the mix, if you will) with the gaseos refrigerant in the A/C system. When the refrigerant leaks, so does the oil. The retail cost of the PART for a new automotive A/C compressor is typically 250-1000 dollars. Protect the enviornment AND your investment and have A/C leaks repaired correctly.
  4. The A/C system is turned on and off by the A/C control panel in the dash and by the vehicle’s onboard computer. Some A/C system problems are related to these parts of the system. These are actually electrical repairs to the A/C system. Good examples are the fan inside the dash, the door that mixes uncooled and cooled air inside the dash, the electric fan under the hood, and the system that selects which vents the air will exit from. Many of these parts of the system are computer controlled in modern cars, and thus, when diagnosing them, a computerized diagnosis will need to be done (this is where the scan tools that shops pay 7000.00 for must be used).

Ok, if your A/C doesn’t work, you need a professional. This is a system that typically cannot be repaired by a layman.

The GOOD NEWS: Most shops do an A/C inspection for free and provide an estimate for repairs. Keep in mind if the electrical control systems have problems, that is electrical work and will carry a diagnostic charge for troubleshooting.

Fianlly some Do’s and Dont’s

DO: Get a professional to diagnose and fix your A/C system.

DO: Your homework and be informed. Many auto A/C system last for 10+ years so odds are if you have a failure, you will not be familiar with the terminology and functions of the parts that need to be replaced.

DO: Get a second opinion if you are skeptical. These can be expensive repairs, and we want you to know where your money is going and why.

DON’T: Just buy the top-off can from the parts store and pack some extra refrigerant in the system. This could cause high system pressure and damage components that might currently function. A/C systems cannot work with air in them. Therefore, topping off ALWAYS creates a system with non-pure refrigerant that will cause incorrect pressures. Also, frequently incorrect or insufficient A/C oil levels result, which can cause additional failures.

DON’T: Use low quality re-manufactured or used parts. Every-time an A/C system must be opened, the refrigerant must be evacuated and at the completion of service, recharged. This part of the job usually costs around 110.00. Using cheap parts WILL result in a you spending additional money on your car!


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