Symptoms of a bad ac Condenser in Car: Diagnose and Fixes

The car condenser is a vital component of the AC system that converts refrigerant from gas to liquid state so it can travel through the air conditioning system. The condenser works as a heat exchanger, and during the conversion state, a tremendous amount of heat is forced out of the refrigerant. Suppose the AC condenser clogs or is damaged; it will lose the proficiency of converting refrigerant into liquid state needed to generate cold air.

However, the car ac condenser does not carry out the converting process alone. The condenser fan and the radiator fan are designed to keep the condenser coil during the heat exchanging process to effectively convert refrigerant into liquid form to provide peak performance. Usually, when the condenser starts to deteriorate or fails, it will show symptoms of a bad ac condenser in the car to notify the driver of a potential issue with the AC system.

What does the AC condenser do?

What is an AC condenser in a car, and what does it do? The AC condenser is in the front of a vehicle. It’s typically placed close to other heat exchangers in the engine bay, such as the radiator or the intercooler, and its operation is usually supported by an electric fan. Making sure the condenser is operating properly is super important because it affects the operation of the entire AC system. The AC condenser is an essential Ac system component typically found on all newer vehicles. It converts the high-pressure refrigerant coming from the compressor to a high-pressure liquid form, through a condensation process.  This happens in a heat exchange process where the refrigerant heat is expelled and exchanged with the outside air.

how to check car ac condenser

Now, if your condenser isn’t the par, this will make the AC system unable to produce cold air. But what’s even more important is that a malfunctioning condenser can expose other system components to accelerated, premature, and extensive wear. Specifically, the AC compressor will overheat if the condenser is malfunctioning.

Symptoms of a bad AC condenser in a car

Since all the refrigerant in the AC system passes through the condenser, any problem with it will negatively affect the entire system operation.

  • Noticeable leaks
  • Lukewarm Air from Vent
  • Burning smell
  • Overheating on idle
  • Warning light

Lukewarm Air from Vent:  The common and first sign you will notice when your AC condenser fails, is warm air from the dashboard air vent. When you turn ON your air to the minimum degree and expect cold air but instead notice ac not blowing cold air, you should diagnose the condenser for missing fins, leaks, and blockage, affecting optimum system operation. If the flow of refrigerant or conversion process is interrupted, the system will lack peak performance.

Overheating on idle:  You might wonder, can a bad ac condenser cause overheat? Of course, yes. For some reason, and as you know, the car ac condenser is known as a heat exchanger because it expels heat out of the system. When your AC condenser deteriorates or has inner clogs, it won’t successfully force out heat from the AC system. Typically, the AC condenser fan cools the condenser when you start your engine, but if too much heat is built up by a lousy condenser, then the Fans won’t be enough cooling.

Burning smell: when the car can’t release the built-up heat in the air-con system, then the pressure of some components in the engine compartment will start rising to the state of burning and emitting a smell when you switch ON the AC.

Noticeable leaks: A more obvious car AC condenser problem is noticeable leaks, which sometimes appear as oil residues on the condenser. Over time, you will notice leaks on the condenser either due to improper installation, age, or bent tubes. If the condenser has critical leaks, depending on where and the cause of the leak, all the refrigerant on the high-pressure line will eventually leak out and cause low Freon in the car, disabling the entire air conditioning system.

Check engine light: Most newer cars are equipped with a warning system that detects the air conditioning unit’s issues and triggers a warning light on the dashboard. Check your owner’s booklet and see if your car is equipped with these features and if it’s something you should always watch out for.

How to diagnose car ac condenser

Let’s look at how to check the car ac condenser. Not only checking the condenser is easy and effective, it’s also a priority for a periodic inspection of the AC system. Diagnosing your AC condenser periodically can save you a lot of expenses and headaches. A lot of people don’t priorities the condenser during system inspection but are focused on system charge, leakage, or compressor operation and what they don’t realize is that a lot of times, the system problems have their root cause in the condenser problems.

Since the condenser is exposed to extreme wear and tear, it’s made of fin aluminum and works with highly pressurized refrigerant, and it’s pretty fragile, It doesn’t take much to leak or break. Now, one of the tools you need for this inspection will be your eyes, that’s right. I recommend a regular visual inspection of the condenser surface and that you replace it whenever you find a severe problem. It can save you from system and compressor repairs – and having the car already in the garage; it won’t take too much time to perform a simple visual inspection.

The only way you’ll be able to tell if there are any potential signs of failure is if you have unhindered access to the condenser and its entire surface.

Corrosion: One of the things you want to keep an eye on is corrosion – especially underneath the condenser where tubes and fins are exposed to humidity softening the most. The corrosion often starts with the fins between the channels. Even if they still look tight, the deteriorated fins will always lead to deficiency in the AC system.

Missing fins: One row of missing fins can decrease the condenser capacity by 5%, and an ineffective condenser will increase the workload on other system components, especially the compressor. And in a worst-case scenario, an ineffective condenser can become overheated and have a complete seizure. Now, without the fins, the entire construction of the condenser gets loosen and destabilize. In a shaky environment like the engine compartment, it might now be normal for the condenser to have a severe leakage as the tubes disconnect from the sidetracks.

Refrigerant leaks: The next common problem of the condenser is leakage. Leaks can also be spotted on the condenser surface and should be considered a threat to the system.

Remember: Leaking leads to a lack of refrigerant which means the system gets exposed to abnormal conditions without proper pressure and limited lubrication.

Oil residues in the condenser indicate leaks. As the oil travels along with the refrigerant, once there is a leak, the gaseous, the refrigerant escapes through it, and the oil leaves tracks. Now, the leak could be caused by corrosion or mechanical damages. The range of root causes can be pretty wide and difficult to avoid. Pressure cleaners, improper installation, insects, rocks, or even fender benders can damage the fragile condenser surface and cause critical leaks.

Using UV lamp: Most of the condenser leaks can be spotted using UV lamp by sparking the dial and tracking the tubes or using other tube detecting tools. This visual inspection method can also help you spot other failures that are no leaks. You should always replace the condenser if it’s leaking, has missing fins or deteriorated fins, bent tubes, or inner clogs.

So remember, always include a visual inspection on the condenser whenever servicing a car. Potential leaks and severe damages can be prevented

How do you change an AC condenser?

After noticing one or more of the symptoms above, and an inspection proves the AC condenser is the culprit, the next thing you want to do is find out how to replace the ac condenser or take it to an HVAC expert for replacement. The good news is, I’m going to show you how to change the car ac condenser.

can a bad ac condenser cause overheating

Materials Needed:

  • Common socket set
  • Wrench set
  • Vacuum pump
  • Eye protection
  • AC manifold toolset
  • AC line O rings
  • Condenser
  • Refrigerant R134
  • AC refrigerant Recovery tank

Discharging and recovering the air-conditioning refrigerant: Connect the AC manifold toolset. Ensure the connections are tight and there are no leaks. The manifold toolset has three lines; yellow, red, and blue. Connect the yellow line to the recovering machine. Then, connect the red hose to the high-pressure line and the blue hose to the low-pressure line. Start the engine and check all the pressure. Wait for about 30 minutes for the machine to recover all the refrigerant. Once the recovery process is complete, the gauge should read zero.

Removing components blocking access to the condenser: You have to remove every component blocking your access to the ac condenser. This might include; front bumper, headlights, mounting brackets, radiators, condenser fan, or grill. Do not remove the condenser yet.

Remove the Air-conditioning lines: Before removing the condenser, you have to disconnect and remove the AC lines. Ensure you put on your eye protection when disconnecting the AC lines in case of refrigerant pressure remains in the system. Also, you want to take off the O rings as well.

Remove the condenser: Now, lose the condenser mounting bolts. In some vehicles, the condenser is attached to the radiator. Once you have loosened the bolts, gently take off the condenser unit to ensure no bolts remain so it won’t snag on any wiring or hoses.

Install the new condenser and the AC lines: Evaluate and compare both condensers. Ensure both condensers match precisely and have the same fitting location, especially if the new condenser is aftermarket parts. Carefully check all mounts and dimensions; if you find any discrepancies, do not mount them. However, if both condensers are the same, install the new condenser with the installation brackets. Coat the o rings with oil and install them to ensure proper seals. Reinstall all the components you removed early.

Place the AC system into a vacuum: Before recharging the AC unit, you have to place the system in a vacuum for around 30-45 minutes using a recovering machine or vacuum gauge and a manifold gauge set. Make sure there are no leaks before recharging the AC system.

Recharging the AC unit: Ensure you use the correct refrigerant for your car, usually R134 for most modern cars. You can find the recommended refrigerant on a service tag underside of the hood, or in your owner’s booklet. The charging is typically done with the engine idling at 1500RPM or more.

Check the AC performance:  After all diagnosis and repair, you want to check the AC performance to see if you did a superb and smooth job. You need to turn on the AC and allow it to run for 5-10 minutes. If you have done an excellent job, the condenser will provide peak cooling performance.

How to Check the A/C Condenser of a Car YouTube

Final word

Tracing the symptoms of a bad ac condenser in a car, diagnosing, and changing air conditioning system components such as the condenser may look like a difficult job. But, it can be done with little assistance. This article pays off as not only did you save car ac condenser replacement cost, it also gives you an insight into what’s under the hood.

Osuagwu Solomon

Osuagwu Solomon is a seasoned automotive technician for the past 9 years, and a technical writer. He loves writing about auto professional repair guides, DIY repair guides, and buyer’s guide. After spending six years in the automotive workshop, he decided to impact his knowledge to people aside his domain, and he has achieved this by centering his Automotive writing skills on REPAIRS.

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