yellowdragon

I've had my DX for 11 months now and I can say I'm very happy with it. The only thing kind of funky was that I felt the air conditioner wasn't cooling like I thought it should... Somehow it didn't seemed 'right'. But then I assumed it was normal for such a small car, auto tranny, high heat of the tropics and comments from other people around here.

Well, last saturday I took it to it's oil/filter change and commented that to the dealer. He said he would check it and after a couple of hours, told me the evaporator has a small leak. He topped the system and made an appointment for next saturday to have it replaced under warranty.

Well now the AC really, really cools! Even under the noon sun, it can cool the cabin in a few minutes of normal driving with the blower at full blast, something it never did before.

My previous rides have had compressors seized, failed blower bearings, loose belts and leaky hoses... But never a condenser fan failure, condenser or evaporator leak.

What could had caused the evaporator to spring a leak? Is this normal? Maybe I've been redlining with the compressor on and raising too much pressure in the system? The car has no tach, but when the engine begins to sound like a bee I assume I should back up a little

Just in case, the car has 45,500 miles...

Ideas, opinions?

Hawkeye

It could be something as simple as the cap that covers the schraeder valve for testing/filling. I've seen systems in homes that are otherwise sound, but have lost some of their charge through a slow leak in the valves.

yellowdragon

Hello Hawkeye... Thanks for your input... After having the system fixed, I'll unscrew the caps a bit and put a dab of silicone so they'll not get lost...

carguycw

I'm not sure what system is used in Puerto Rico, but all U.S. and Canadian Proteges have R-134a systems. AFAIK no R-134a auto air conditioners have Schrader valves, and the type of valves they use look like they are VERY unlikely to leak. I'm not sure if applying silicone to the valves will accomplish anything.

FWIW I recently replaced my evaporator- unfortunately not under warranty because it cost me almost $300 in parts WITH the Team Support racer discount. Unfortunately, I think the leak was caused by the design of the evaporator. It consists of a "sandwich" of stacked pieces, and the leak occured between two of the elements (look at a Protege evaporator and you'll see what I mean). Now that G3 Proteges are getting older, I'll be interested to see if this evolves into a common problem.

Hawkeye

The valves that I'm referring to are on the passenger side of the engine bay. The high side is near the radiator and the low side by the passenger side strut tower. When I removed the cap, I did hear a slight hiss which indicates a slow leak in that valve. Therefore, the caps prevent the leak. There's an O-ring in the top of the cap. Applying silicon to that (grease type, not adhesive type) ensures a good seal between the O-ring and the housing of the valve, thus (hopefully) preventing the leak.

UHZT

I live in Barranquilla (Colombia caribean) and i got the evaporator replaced by warranty at 22000Kms, because some minor leaks. The dealer said to me Mazda has a recurrent problems with the Protege evaporators in cars running at high ambient temperatures (here abouth 88F) sea level with agressive enviroments (salt) due to some design problems and bad welding procedures. The new one is a new design under test.

regards
UHZT

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Silver Y2K Allegro (Protege) 1.6L
K&N drop in air filter
Custom side sills kit
Hiperground wiring
Bosch anti fog
900 Watts audio power

carguycw

That's interesting. My evaporator appears to have failed at one of the welds just like your dealer described. I suspected that it has something to do with heat cycling during summer in hot climates (like North Texas)- i.e. the evaporator sits under a hot dashboard in the summer sun, gets heated to 120-130 degrees F, then drops to 32-35 degrees F when the a/c is switched on. After a few years of being suddenly cooled by ~90-100 degrees F multiple times per day, the thermal stress pops the welds and the refrigerant starts to leak. The evaporator consists of a "sandwich" of skinny elements that are stacked up and welded together, providing plenty of potential failure spots if the welds aren't perfect.

Again, I'll be interested to see if this becomes a common problem as G3 Proteges get older.

yellowdragon

Carguycw;

We have the same system as in the states... R134a

Anyway on saturday I'll ask the dealer if he has seen that problem frequently in the Protege. I believe he has as he had to order a new evaporator because they didn't had any in the shop.

I'll also warn my sister as she has a 2002 DX... We're becoming a Mazda family...

yellowdragon

Well, my car had the evaporator replaced today. Interestingly, the job was done somewhere else...

The A/C cools very nice now, even when standing still without having to shift to 'N' while accelerating a bit... And also I can really tell when the compressor engages, especially when taking off from a traffic light. The engine loses some power but regains it quickly. This is surprising because my SO used to have a '96 Hyundai Excel which had a nice feature that I thought Mazda had too... His compressor would disengage while accelerating and reengage a few seconds after reaching the desired speed.

Now I have a question, can the evaporator be replaced without taking apart the console? I'm asking because my radio was not disconnected.

Mach 1

The valve leaking and the evaporater leaking are two different things. He asked how his evaporator could be leaking, not how his valves could be leaking. the valves are no where near the evaporator.

Yelowdragon- you said in your first post that the car was fixed already, but now your last post...? whats up?

carguycw

It's remarkably easy to remove, and no, you don't need to remove the console. You just remove the panel around the glovebox, drop the glovebox, undo the refrigerant lines, then remove two nuts at the top and bottom of the evaporator unit and viola! you can pull it out. It's cake.

Hawkeye

The valve leaking and the evaporator leaking are two different things, but the result is the same, loss of refrigerant. Therefore I was trying to help him knock out the easy stuff before condemning his evaporator. Without a leak detector it's difficult to determine where the leak is, so he couldn't say for sure it was his evaporator leaking. It doesn't matter if the valves and evaporator aren't near one another, a loss of refrigerant is a loss of refrigerant.

I guess that's what I get for trying to help. I suppose the fact that I'm a licensed HVAC tech means nothing.

yellowdragon

Mach 1; thanks for your concern. What I mean is that you can tell when the compressor engages because the engine loses some power. But it could be because the system wasn't completely full since the day I bought the car. Anyway I'm just getting used to it...

carguycw; thanks for the information. It seemed to me that the whole dash had to be removed to gain access to the core. Guess that's a testament to the good engineering practices at Mazda... Unlike my old 2.5 TBI Chevy S10, in which I would *always* break the #1 spark plug (the one closest to the front) because the air conditioner compressor was in the way...

Hawkeye; thanks for your comments. The dealer had diagnosed a leaking core and it was replaced. But before that, I did took off the valve covers and applied soapy water to see if the problem was there. Also applied silicone grease to the O seals.

Mach 1

I suppose the fact that he mentioned in his first post that the dealer already diagnosed his evaporator as leaking, and therefore there was no reason to "knock out the easy stuff" first means nothing?

djs2571

I have an 07 M3 GT and I looked at the A/C lines, removing the caps I heard the little hiss of pressure escaping. Looking further I could see small bubbles coming from the valve seat, so there's definitely a leak on the high and low side.
I checked the pressure on the low side, and when it's all off and cool there was 100PSI, when it was on, just for a minute, it was fluctuating between 25 and 30 PSI.
Figure this may come in handy if someone is checking thier system for leaks, apparently the caps can hold this pressure back when they are working properly.