When it’s a million degrees out and your AC isn’t working right, it’s about as aggravating as getting kicked in the head. The heat makes you feel so sticky and uncomfortable you can’t even think because your attention is focused on getting cool immediately. However, sometimes it’s focused on dodging ice particles flying at your face. I know you’re thinking, “what the heck, why is my car blowing ice?”

There are only a handful of reasons why you could find your car blowing ice particles when the AC is turned on. Low/ leaking refrigerant, a clogged cabin air filter, or a faulty evaporator temperature sensor. Chances are at least one of these issues, if not a combination, is the cause of your problem.

Table of Contents

How To Diagnose What The Actual Problem Is

Diagnosing and troubleshooting any car problem can be challenging. Getting it wrong means time wasted and potential money down the drain chasing the wrong solutions. However, when you do get it right it can be gratifying and empowering knowing you’ve correctly solved a problem all on your own.

So because of this, my system for solving any automotive issue including HVAC problems like this one involves systematically eliminating all potential issues before moving on to the next. It allows for the most thorough analysis without scrambling all over the place.

Start Step By Step From Easiest To Hardest

When solving any problem you want to start with the easiest and cheapest solutions first before working your way up. This insures that one you don’t waste unnecessary time on complex repairs and two, that you don’t waste precious hard-earned dollars on fixes that could have been done at a fraction.

For our ice problem, we want to attack it precisely in this order to make sure we’re being efficient with our time and money. For each step that doesn’t reach our desired result (no more ice chunks from vents) we move on.

Replace Cabin Air Filter

car blowing ice
Dirty Cabin Air Filter VS New

Cabin air filters control the amount of airflow that the blower can pump out. It can be a bottleneck in your HVAC system especially when it’s clogged because your blower motor has to work hard to pump the air.

When you turn your AC or heater on it sucks in outside air which then passes through your cabin filter before it enters the cabin. The cleaner the filter, the easier the air can pass through.

When obstructed, a cabin filter can cause moisture to develop on the blower fan blades and inside the HVAC ducts from unequal airflow.

When your AC is cranking on that hot summer day, the moisture will begin to condense and eventually freeze from inadequate air circulation. This leads to ice chunks being flung at you when you’re trying to cool down in your car.

Cabin Air filters are easily one of the most overlooked items in maintenance which is a shame because it’s one of the easiest items to do yourself. On most cars, it requires little to no tools and can be done by anyone even with no mechanical knowledge.

A cabin air filter is fairly inexpensive as well, ranging between $10-$30 for most cars. I recommend changing your filter at least once a year for milder climates, and once each season for high moisture/dust-prone areas.

Besides everything else, a cabin filter leads to better quality air within your vehicle’s cabin and removes lingering odors that can be trapped. It’s worth changing just for that even if it doesn’t fix the ice from the vents problem.

Replace Refrigerant/Fix Leaks

car blowing ice
AC refrigerant and recapture machine

The lack of refrigerant in an AC system alone generally won’t cause chunks to fly out of your vents because it generally wouldn’t get cold enough. Combined with a clogged cabin filter and lack of air circulation, low refrigerant however can exacerbate the issue by causing spots on your evaporator coil to freeze up.

If you want to continue to have cold air in the future fixing a refrigerant issue is a must. Low or leaking refrigerant is a problem that may not be readily apparent when first looking at your car’s AC system so some special steps are needed in order to accurately pinpoint the problem.

To detect a leak you need to inject a special color dye into your AC refrigerant that will allow you to track the source of the leak. This is because a typical r134a refrigerant is clear and won’t be readily visible to the naked eye.

You can purchase all the equipment necessary online to do this fix on your own but in this one instance, I would probably advise against it. Why do you say? Simply put, the cost.

Sure you could buy all the stuff but ask yourself how often will you use it again. Generally, AC leaks don’t happen that often, at least they shouldn’t. So you’ll have hundreds of dollars worth of specialized equipment to fix a problem that isn’t all that common.

My advice would be to find a reputable mechanic that handles AC repairs. They should be able to leak test, repair, and recharge your AC system all for about the same price you would pay to do it on your own.

If you want to save a little bit of money, you can purchase the leak test dye yourself and inject it into the high-pressure line and find the leak. This way you know what and where the leak is coming from and whether or not you can fix it yourself.

The problem is, old refrigerants can not be released into the atmosphere by law and must be recaptured. So unless all the refrigerant is completely leaked out you need to have the equipment to recapture it.

Change Evaporator Temperature Switch

If you’ve changed your cabin air filter, fixed all your refrigerant issues, and still get ice chunks blowing from your air vents, it might be time to change your evaporator temperature switch.

Your evaporator temperature switch or evap switch for short controls how often your ac compressor kicks in when you turn the knob in your car. Its job is to regulate the AC compressor to maintain the temperature you set in the cabin.

For instance, if you set your ac to 65 degrees on that sweltering hot day, the evap switch will continuously shut the ac compressor on and off as it sees fit to maintain that 65 degrees.

When an evap switch fails it can get stuck in one of two ways; open or closed. If the switch is stuck closed your ac compressor will not turn on and you’ll get hot air coming from the vents.

If the evap is stuck open the ac compressor will never turn off, even if it reaches the set temperature. With a continuously running ac compressor, the evaporator coil or air exchanger will begin to freeze up. This will likely result in our situation of blowing ice chunks.

The good news is that evaporator temperature switches are usually plug and play, meaning little to no effort to swap them out. Getting to the point where you actually can change them is another story.

Generally, evap switches are buried deep within your dashboard so complete disassembly is required. It’s doable if you’re mechanically savvy and have the right tools. Following a guide that shows the layout of clips and bolts is essential, as well as the order in which things should be removed.

Just check out this video by Amesie’s Corner for an idea of what it takes to switch one out.

Taking dashboard apart to change evaporator temperature switch

The entire process is tedious at best but if you do it yourself you can save substantial labor charges by only paying for the cost of the switch itself.

If you’re unable to manage this yourself you may be looking at a hefty bill. Depending on how intricate and complex your vehicle’s dashboard layout is it might take several hours of disassembly and removal to locate the switch. Unpleasant news in that case.

Preventing HVAC Problems

Adequate airflow is essential to maintaining your car’s HVAC system. Dust and other airborne pollutants can clog blower fans and ductwork, so maintaining clean airflow is essential. Replacing your cabin filter is a simple task that can prolong the life of your vehicle’s ac system and reduce the necessity for replacement components.

Also, use or lose it is a thing when it comes to ac systems in cars. Switching on the ac occasionally (in warmer months) will ensure that systems are functioning as they should and clue you in on potential weak points before major repairs are needed such as leaks or clogged filters.

In Sum

If you find your car blowing Ice chunks then it’s the result of failing HVAC components. When you follow the system of progressive troubleshooting, you can bet that your solving problems like this and any other, in the most effective way possible. So go get to fixing Automotivists, and be sure to check out the latest repair guides here for the best info on niche automotive fixes!

 
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