Miasma:0 AC:1
 

Ok, I threw in the towel with my AC, i will fix it next summer.

6/15: Checked pressures at Infinity dealer, recommended recharge, recharged, said compressor had internal failure.

6/30: Ordered new remanufactured compresssor from courtesy and drier, o-rings, oil and nylog.

Installed compressor, recharged system, still crappy cooling.

Since then, i had to get hail damage removed and tranny rebuilt, so a week and a half ago i took my car to a specialized AC shop who said i need an expansion valve.

Expansion valve replaced, still ****ty cooling (low side pressure is too high). They told me compressor was bad, i replaced it under the nissan 12mo warranty.

2nd new compressor installed, still ****ty cooling, basically, since i have had the system flushed, recharged and all moving parts replaced with brand new properly working properly installed parts, the only thing it could be is the reman compressor.

I cant get a new (read: not reman) compressor from any nissan dealer let alone through the warranty. So, I give up until next summer since, i will not risk doing the install myself again and having to pay $100 for each recharge and $400 for the compressor.

Word to those with compressor failures: BUY A NEW compressor and have a shop do the work, it is cheaper in the long run, and they will make it work and you dont have to pay for each reinstall of the compressor or expansion valve or drier etc.

Did you check the Blower Motor? Maybe its on its last limb?

yes, i know that the compressor is at fault, my low pressure is at 65-70 psi and it should never be higher than 35-40psi.

and i know that the expansion valve is good, so the only other thing that affects the pressure is the compressor.

there are no blockages or leaks in the system.

What have the Infinity tech's had to say? Seems like if they can't give you a proper diagnosis then they wouldn't be able to fix it either.

Also are you sure that the low side pressures are affected by the compressor? Seems to me like the expansion valve would have control the low side pressures, but I'm not positive. I made a post on aircondition.com to try and get an answer to this. I have purchased my new compressor, drier, and expansion valve, but have not installed them yet. I moved on to another home project and haven't had time. Also was waiting for good news from you before I gave it a try. Looks like I will have to try it anyway. If I find anything that looks like it will help I'll let you know.

Well I finished my install a couple of weeks ago and it's working OK, but not as well as I would like. I replaced my compressor, reciever/drier, and expansion valve. Vent temps are in the 50's on 90+ degree days, and hitting mid 40's on 80 degree days. I'm not sure how good these temps are, it still takes a while to cool the car down on a hot day, probably has a lot to do with my black leather interior. Everything went pretty much by the book, with the exception of removing the evaporator housing. I couldn't find anywhere in the service manual where it described removing the evaporator box. I found that I had to cut a plastic strip that goes accross the bottom of the glove box opening (after the glove box is removed). The manual diagram does'nt show the strap accross the opening. The evaporator was very dirty and I think this hindered it's cooling ability.

I should also point out that I used 46 weight PAG oil (8 oz for approx $7 at parts store). I actually got one can at the dealer (parts guy said I should only need one) it was 1.75oz and ran $27 dollars. I went back and did some reading and found that our system should have 8 oz of oil.

Miasma - as a side note... I finally found my Haynes A/C manual and in it's diagnostics section it points to a bad expansion valve when the low side is high and the high side is normal. It could also be the compressor, but I'd start there.

From my limited experience...
 

It sounds like you put in a bad Expansion Valve. It really doesn't sound like the compressor is bad. Also, why don't you re-charge it yourself. It's simple, and cheap. Just buy a kit.

You need a vacuum pump and guages if you want to charge it yourself. It wouldn't pay to buy these if you're only working on one system. I know others say you don't need guages to charge, but I wouldn't recommend going without. The cheap low side guages are next to worthless, and you need to be concerned about high side pressures as well.

I've been successful without the vacuum
 

pump by simply "dumping" in the 1st can, and then bleed out most of it, and then "feed" in the next 2 cans via suction. You are right, if you have a probelm, you need gauges to diagnose what the problem is, but for $5 per can, it's worth a $15 gamble.

From my A/C knowledge, this points to a problem with your expansion valve. Your compressor is giving you pressure, it's doing it's job correctly. The expansion valve isn't holding it back enough to lower the low side correctly.

Is your high side within specs? If so, then definately hands down, you need a new expansion valve.

my expansion valve has already been replaced with a brand new unit, sorry guys, its the compressor, i too was getting ~53F temps on 90F+ days and 40's at night, so, it was not too bad, but the compressor is still crap