Mazda MX-6 Forum banner

a/c iced over

3K views 12 replies 4 participants last post by  TwoPedalWarrior 
#1 ·
I have been posting some issues with my a/c. Now this is a new thing that came up, so thought I would start another thread.

I went on a trip this week. When I was coming back, it was hot enough to need the a/c. Turned it on, and it blew really cold, more cold than needed.
It was only blower position #2.

About 100 miles later, it seemed to be getting warmer in the cabin. There didn't seem to be much air blowing. Turned it up to position 3 and 4. The air was cold, but not much was blowing, it was much less than it should have been. I thought maybe the blower was malfunctioning.

Soon needed to stop for gas. When I opened the hood, the low pressure line
was completely covered in ice about 1/8" thick. I am only guessing the blower was iced or something too, so it stopped the air flow.

After knocking off the ice, the blower air flow felt like it returned to normal.

Any idea about these 2 problems - the icing, and the blower air amount ?
 
See less See more
#4 ·
expansion valve should be the issue. before changing it insure the sensing probe is making good contact with the low side return line
 
#6 · (Edited)
Went on another long trip this week. Low pressure pipe iced over again. I stopped, and chopped off
the ice. Then I turned on the heater, to take any ice off the evaporator. I didn't know there is a drain hose right next to the firewall. A lot of water poured out of that, then went to a trickle. The rest of the trip, there was condensation on the low pressure pipe, but it didn't freeze over again. Maybe just not long enough period for ice
to form.

[/URL][/IMG]
 
#7 ·
I finally finished up this project and got my air conditioning back, just in time for the Houston
summer.

It was not that difficult, and saves a lot of money from having the shops do this. I have heard it can go into the thousands of dollars. You need patience, though, and it will take time, so it won't get done in 1 or 2 settings. But you can drive the car while this is being done.

I put in a new condensor (leaked), new evaporator and expansion valve, new dryer, new low pressure hose. The a/c compressor works okay. Total cost was about $ 200. In terms of how the work went:

condensor - easy to take out and put it if you take your time
dryer - very easy
low pressure hose - very easy
evaporator and expansion valve - difficult to access, have to find the bolt way inside in order to be able to remove the box these are in. Have to take out all the panels around the glove box. Once accessed, easy to put in a new one, except it will take time to push it in and seat it properly against the fire wall.
 
#9 · (Edited)
[/URL] I don't know about a DIY, but here are a few photos if you ever need to recharge your system, and don't want to pay a shop to vacuum the a/c lines and put the refrigerant in.

I got these 2 inexpensive items at Harbor Freight - a 12v air compressor than runs off the cig lighter, and a vacuum pump. Surprisingly it pulls a pretty good vacuum. Total cost about $ 35, and you can do this whenever you need to. After I did this, it easily took in about 2 cans of refrigerant. And you can fix a flat on the road, if you have the patch !

[/URL][/IMG]
 
#11 · (Edited)
The photos above are just from when I was testing the pressure holding by using the air compressor. After that, I used the air compressor and vacuum pump to create a vacuum. After that was complete, refilled with refrigerant, 2 cans. Only drawback to this system is the hose with the gauge doesn't show negative pressure like the fancy manifold gauges. Seems to work though, as air
in the cabin is pretty cold now.




 
#12 · (Edited)
AC is working well. This seems like a good way to go, as total for all parts including hoses was about $ 450. That replaces everything except for the steel tubes. Much better than a shop doing endless testing. One thing I didn't know is that when the car is not running, the pressure will equalize, so there is a a much higher reading on the low pressure side then. If the car is running, the low pressure side will drop to normal range.

Low pressure side when running


Without ac



With ac
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top