May 13

2007 Mazda MX5 Miata, AC Repairs



Mark: Hello there internet people, it's Mark from Remarkable Speaking. I'm here with Bernie Pawlik Pawlik Automotive in Vancouver. Vancouver's best auto service experience and 24 times, they've won best auto repair in Vancouver as voted by their customers. We're talking cars. How are you doing Bernie? 

Bernie: Doing good.

Mark: So today's victim is a 2007 Mazda Miata. It had some AC problems. What was going on with this vehicle? 

Bernie: Yeah, so the owner had you know, found his air conditioning, wasn't blowing cold air. So it was time to repair it. We're in Vancouver. There's a certain season for air conditioning in Vancouver. Although, as we've talked about in the past, it's always good to have air conditioning, working year round for safety reasons. It defrosts your windshield and windows faster. So it's good to have air conditioning working in the winter, even though people don't think about it. But anyways, it is getting into the warmer season and the air conditioning isn't working. So this is when we do a lot of our repairs around the Vancouver area. So that's what was going on with this car.

Mark: So what kind of inspections and diagnosis do you have to do with an AC system? 

Bernie: So there's sort of two main areas with air conditioning. It's a pretty complicated system. I mean, it's a system in and of itself. It's basically the same as your refrigerator. So it's kind of cool part about being a good auto mechanic, your auto service technicians, you've got to know how to fix refrigerators too. Automotive refrigerator. So anyways there's really two areas where problems happen.

One is in the electrical side of the system and the other is in the gas side, the refrigerant, the chemical that causes the cooling. Most of the issues with our air conditioning are caused by the chemical coolant, it leaks out. You know, the thing with the car is, it's kind of a hostile environment as opposed to your fridge which just sits in a corner. Cars bounced around it's twisted. It's under a hot hood. It's heat, cool, freezing temperatures. So it's under a lot more strain than you get on a house refrigerator. So anyways, electrical faults do occur and that can cause a system not to switch on, but most often it's a leak.

So we start with a visual inspection. Is the system turning on? In the case of this car, it wasn't and it will not turn on, on most cars. The compressor that is, if the refrigerant level is too low. So usually the first place to start is, is there refrigerant in the system. And that's where we kind of start our diagnosis. 

Mark: So you mentioned a compressor. How does the, and it's a gas, what actually is happening? What's causing the cooling. 

Bernie: Yeah. So it's kind of neat how air conditioning works. So this gas in this vehicle, it's called R134A, that's the refrigerant. So it's a chemical that is liquid or gaseous, depending on the temperature and the pressure and the way air conditioning works is it has a compressor which will compress the gas, or is it the liquid? Depending on what state it's in, but basically the compressor will compress the gas. It goes into the condenser, that's the piece of the front of the vehicle. And as it changes state, it will disperse the heat out to the outside environment. And that turns into a liquid goes back to the evaporator, which is like a little, it's like a heater core.

So like another radiator inside your car. And that piece, as the gas changes state, it causes it to get very cold. And so that cools your car down inside, but at that picks up the heat inside the vehicle, it goes back out of the evaporator into the compressor gets recompressed. It goes out to the condenser, which as the word implies, condenses, it condenses it into a liquid. That disperses as heat. So it's just a heat transfer system, basically how it works. 

Mark: So it sounds very complicated. How do you find a refrigerant leak in such a complicated system?

Bernie: Yeah, so this is the other thing, not making excuses for work, but it's very complicated to find. It can often be complicated to find leaks in air conditioning systems because so many of the components are hidden. The evaporator core is under your dash. Sometimes it takes five to eight hours just to actually take the dash out and the heater and the box to actually access the evaporator core.

So it's a lot of work. If there's a leak in that thing, it's hidden. Unless it's a massive leak, it's often difficult to find. There are pipes and hoses that run throughout the vehicle, through the engine compartment, into the firewall. They can leak from number of sources.

We can usually see most of those leaks and hoses, but sometimes they're hidden it. It's tricky to find. The condenser, which was located at the front by the radiator. Again, depends on the car. Sometimes they're easy to see, sometimes they're not. And even when they're easy to see, sometimes a leak is hard to find.

So we have methods of finding leaks and the best one is, there's a UV dye that's usually installed in the air conditioning system. If it's not in there we put it in, and that dye will, even a slightest amount of a leak, we can look with a special ultraviolet light with yellow glasses and you can usually see a lime green glow where there's a leak. 

So the good news about this car is the leak was very evident when we found it. So it gives us a good example for this podcast to show what was going on. So as you can ascertain, the electrical system of the air conditioning was fine. The problem was actually a refrigerant leak. So I'll get into some pictures right now. 

2007 Mazda MX5 Miata, AC Repairs


So there's are a Miata. Okay. So the leak which we found was coming from in front of the condenser. So we actually replaced the condenser a few years ago for this customer. Now you can kind of see this greenie colour and it's oily here. This is a beautiful, when we find this, we go, excellent. We found the leak. This is nice to find because so often when we look at an AC system, we go through it. Oh, we look everywhere and we can't find the leak. Is it in the evaporator? We know if the refrigerants out, it's got to have leaked somewhere, but we don't want to just recommend, Hey, let's take the dash apart for, you know, the $2,000 job only to find that there's nothing leaking. We want to be sure before we do that. 

2007 Mazda MX5 Miata, AC Repairs

So anyways, there's really good evidence here. There's a seal that goes where this pipe, this is called the liquid line. There's a seal where this pipe goes in. And I figured it was probably the seal, but just to be extra cautious, I employed a couple of our other leak detection methods.

We charged the vehicle with nitrogen gas. We can add high pressure nitrogen gas, and that can often flush out a leak that isn't evident. So what I did, I sprayed some tire leak detector foam, it's like a little liquid that that'll bubble on this particular area here where the leak was just to see if I could see any bubbles, interestingly enough, nothing showed up.

And this is where, it's obvious that it's leaking, but sometimes it can leak so minutely that it won't even show up or they'll only show up under certain temperature or pressure condition. So even 300 PSI of nitrogen gas pushing it wouldn't cause it to leak at this moment. I also used a, we call them a sniffer, but it's basically an electronic leak detector.

And if there's any refrigerant molecules in the air, it'll start beeping. Again, it didn't beep either. There was enough refrigerant in the system with the nitrogen that it should've caused beeps and it didn't so again, very minor leak. So this may have taken a couple of years to leak out or a year. You know, it depends.

 I know it was at the end of the day, concluded it was a seal, there was some corrosion that had developed. This is a very low point in the car and water can get in here. There's some corrosion that developed between the aluminum here and the steel bolt and that probably caused a slight amount of shifting in the fitting and caused a leak. So put a new seal in, cleaned everything up and it was good.

Mark: So that was the repair. You didn't have to change the condenser, you just changed the fitting?

Bernie: Yeah. It was pretty simple actually, in this case. Then we put the system into a deep vacuum. It's really important to remove any moisture from the system. And how we do that, we have equipment that will actually put the system into a deep vacuum. So we do that for about a half an hour or longer. And then we actually vacuum test assistant and make sure it holds the vacuum. That's not a foolproof method of finding out whether there's any further leaks, but sometimes it's helpful. If you do a 10 in a vacuum test and it fails the test, that's usually a sign that there's a leak somewhere. But we did that and passed, filled it with refrigerant, worked fine. 

Mark: So I guess this kind of, a lot of people would look at this problem, Hey, I'm low on refrigerant, I'm just going to refill the refrigerant and it's just continue with the problem, perhaps even getting worse. Is that right?

Bernie: Absolutely. This is why it's really important to diagnose the issue. And I mean, we have cars where we do a diagnosis and we can't find a leak, at least nothing obvious. And of course we don't want to, as I said earlier, you know, sometimes to take the dash apart could be 8 or 10 hours worth of work. It's a huge amount of money to spend on something that we don't know.

So it's sometimes better if we can't find a leak anywhere, we do the best we can to use a number of methods. If we can't find a leak to recharge it and see what happens. And sometimes a leak can be so small and so minor that it could take several years for the refrigerant to leak out. I mean, you don't want it to leak at all, but it's not really the worst situation. Sometimes you just gotta do that. 

Mark: And any environmental concerns around handling AC refrigerants? 

Bernie: There is. So these AC refrigerants are restricted items. You 're supposed to have a refrigerant handling certificate to buy any refrigerants, to be honest, no one at any auto parts place I've ever bought refrigerant from has ever asked me if I have one. Which is interesting. I guess they assume I'm honest and decent, but you know, you are supposed to have a refrigerant handling certificate to buy it. 

There are also some alternative refrigerants on the market, which I'm not really a big fan of cause they use hydrocarbons for the refrigerant. They're actually cheap and actually very effective. There's just a slight risk that if these leak into the vehicle, like if you have an evaporator core leak, and suppose you were a smoker and you lit a cigarette and there happened to be a leak, your car could explode. Very rare, not too many people smoke anymore.

You know, and it's obviously not something of an issue, otherwise they wouldn't allow these refrigerants on the market, but these are good alternatives if you have an old car that used to use R12 refrigerant. You don't want to retrofit it. But we don't use them. We use the proper refrigerants. 

I'll just show another picture of what we do to test refrigerant before we actually hook it up to our equipment because we're supposed to recover these refrigerants. We don't just let it vent to the atmosphere.

2007 Mazda MX5 Miata, AC Repairs

And so it's really important that we have the pure refrigerant that we suck into our machine because it's reused. And if we could put contaminated refrigerant in, it will foul up all the refrigerant we put in subsequent vehicles. So this is a refrigerant identifier tool.

And basically this is the first thing we hook up, it tests and lets us know that this is pure R134A. There's no air in the system and there's another screen. I didn't take a picture of it, but it shows it shows if there's R12 or R22, different refrigerants in the system. And so we can see if it's contaminated.

We actually had another vehicle yesterday that I worked on. It was contaminated hydrocarbon refrigerants, and then this machine just started beeping and went, you know, highly contaminated refrigerant. So so it's a good thing to have because otherwise you end up wrecking your equipment. And then contaminating other people's systems down the line.

Mark: So back to the Mazda, how did it run after the repairs and how are Miatas for reliability? 

Yeah, well, okay. So the air conditioning blew nice and cold. The compressor switched on and off, like it's supposed to, we test the system pressures. There's there's pressure gauges we hook up that we can test how it's working, all worked fine.

Bernie: I'm assuming, you know, this was the only leak that we found. That doesn't mean there isn't other leaks in the system and we all tell people, Hey, this is what we found. There could be more. Because you know, sometimes you can get a little disappointed when you have your repairs done. And then it leaks somewhere else. Anyways, ran great. And these are really reliable cars. I like these. I've often thought for many years that this is the Japanese reliability solution to the English sports car, the small little English sports car. 

So, yeah, they're really good. There's not a lot on the road, but we even work on many really old ones because it's a kind of car that people want to keep. Their kind of classic and they'll just spend money on fixing. We did it did a head gasket on an older one, not too long ago, which is a pretty major job and the customer put a new top on it. And so, you know, there it's a nice car and definitely worth keeping and a reliable. Unlike your English car, where if you have a MG, not many of those around you know, it needs a lot of tinkering, but Miatas do not need tinkering.

Mark: If you're looking for service for your Mazda in Vancouver, the guys to see are Pawlik Automotive. You can reach them on their website You can book ahead. You have to book ahead. They're busy and they'll call you back. They'll get ready for your appointment. They'll be inquiring about what is actually going on with your vehicle and let you know what the next step should be. You can call them at (604) 327-7112. Of course, they're busy. So be patient, there is humans to answer. They're not always available, but they'll be there soon. They'll get back to you. And of course you can check out our YouTube channel, Pawlik Auto Repair, close to a thousand videos on there of all makes and models and types of repairs. The blog on, same story, lots of videos, lots of stories. Thank you so much for watching and listening. We appreciate it. Thanks Bernie. 

Bernie: Thank you, Mark. Thanks for watching.

About the author 

Bernie Pawlik

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