Hello again. I have been trying to read up on the issue I have been having with my A/C to no avail, because much like before, I do not even know where to start other then the commonly suggested add some refrigerant that I get when I ask people I know offhand.

The problem is that awhile back, before it started warming up, I depressed the A/C button and heard a sound that reminded very closely to what it sounds like when you stick a playing card in the spokes of a bicycle. I smacked the side of the dash and it stopped.

Now fast forward to present day, with it warming up in my area I needed to actually use the A/C for the first time in a long time. I pressed the button and now a sound (I do not know if it's the compressor, blower, or where it is originating from as of yet) that reminds me of "mystical" sounds that you hear at the end of songs. Kinda like one of those instruments where they drag a hand or stick across a bunch of windchimes (the name for it escapes me). The air also does not change in temperature whatsoever!

Where do I begin to examine the root cause of the issue. I have the Haynes book and have read through it once, but also wanted to know what expierenced people like yourself thought should be my plan of attack.

Should I dump some refrig in it (I know I may have a leak, but sheesh it's hot), and see what happens?

Just need some help getting started and pointed in the right direction, after narrowing down the potential causes, I'm hoping to lick this myself.

I know it's going to be a scorcher, but I want to try to do this myself if it's not to major because I need to save the money. I doubt I could afford what a mechanic or a/c specialist would charge currently.

Thank you for the help!

Happy Easter!!

Does it sound like there is trash/twig/stick/weed in your blower?

Does your compressor kick on with the A/C button pressed?

Does your compressor Kick on with the defroster set?

Is the temperature selector set to cold?

Is the vehicle running?

These can help us troubleshoot with you.

Does it sound like there is trash/twig/stick/weed in your blower?

No, I am having a hard time describing it, it kinda sounds like sand being whirled in a glass bottle or a bit like air leaking out of something, not a hiss though.


Does your compressor kick on with the A/C button pressed?

Yes.

Does your compressor Kick on with the defroster set?

No. If I am correct in assuming the defrost is the rightmost setting on how you want the air to come out. I turned the knob there and pressed the a/c button but did not hear the compressor engage.

Is the temperature selector set to cold?

Yes it is, there is no difference whatsoever in temp when pressing the a/c button.

Is the vehicle running?

Yes, I don't think my compressor engages when the car is not running and I press the a/c button.

FYI, in order to get the compressor to engage when you are in the defrost settings (knob all the way over to the right "windshield" settings), you have to turn the blower fan on. It doesn't matter whether or not you also have the AC button pushed in. The compressor should come on in defrost with fan on regardless of the position of the AC button.

I have no other advice for your problem though, sorry.

is the temperature HOT? or just not cool? does moving the slector hot/cold change the temperature? (is the temperature control on the head unit broken?)

Does the air flow change locations when you select vent/floor/defrost etc? (Is the vent selector broken?)

how long had the A/C been on before you decided it wasnt getting cool? on really hot days, it can take my truck a few minutes of driving to start to cool well.

Can you have your pressure checked? If all of the above is working, and the compressor is clicking on, then the only thing left I can think of is either the freon is low, or something is broken and its not pressurizing the system.

Run the A/C for a while, and you should notice condensation develop on one of the A/C lines under the hood. thats a good sign, things are working.

However, if no condensation, or has low pressure, or all else fails:
You could pour some more freon in, but if it leaked out once, chances are its gonna leak out again. May need to have it serviced if you cant find the leak.

Auto parts houses sell the refrigerant cans with a hose and an inline pressure gauge. I bought one to eliminate any guesswork when debating when I'm having A/C problems.

Can't remember I paid more than about $20 US for the kit.

is the temperature HOT? or just not cool?

It feels about the same as the outside air.

does moving the slector hot/cold change the temperature?

Yes, I can get the temp to rise by turning it to heat. I don't think the selector is broken.


Does the air flow change locations when you select vent/floor/defrost etc? (Is the vent selector broken?)

Yes it changes locations. I don't think the vent selector is broken.


how long had the A/C been on before you decided it wasnt getting cool?

I've given it plenty of time on multiple occassions. It's not getting cool.

Can you have your pressure checked?

I was considering getting a kit like Xorand mentions, but I wanted to be sure I to eliminate other factors.

I also watned to be sure it was an option. I understand it may leak out (and hopefully is envrinomentally friendly now like they say) but would like to try if it is an option.

1) If there is no leak, how does the refrigerant get low?

2) If I do recharge it some and there is a leak, could I try the leak fixer stuff they sell or should I seek professional help at that time?

Thanks for the help, I'm burning up during the days now but still trying to hold on to my wallet

Ps.

When I change the selector to defrost, the compressor is kicking on regardless of whether the a/c switch is pressed.

Also,

When purchasing the refrigerant, should I opt for one that is just refrigerant or one that refrigerant and includes oil? What about one that includes refrigerant, oil, and leak sealer? (I did see in another post a user with bad results with leak sealer so I'm skiddish of it already)

I don't understand what the oil is really and if there are any pitfalls to using leak sealer so any information would help immensely.

Also, what pressure should I recharge it to?

I could be mistaken, but looking at the High side of my ac tubing, I notice there is an oil like substance (I imagine that oil normally suspended in the refrigerant) on the black hosing that forms a connection.

I think I'm gonna try to recharge the refrigerant tomorrow and have it examined by a mechanic when I can. I'm hoping it's a really slow leak cause I'm not sure when I can get it in.

I'm hoping to avoid a costly visit and would appreciate any advice on specifing what I believe is wrong and ask him to check for other issues (but not take me for a ride).

I had this in mind "I believe there is a leak in the High side pressure hose, there is some oil residue on it, but would appreciate you checking out the other components and giving me an estimate for repairs".

Also, any guides on price? I've seen some far ranging numbers. I've seen the hose listed from around $6 to $100 (on forums) and labor ranging almost as wildly so any help on what to expect would be great.

I wanted to condense all the questions I still could use some help with.

1) If there is no leak, how does the refrigerant get low?

2)When purchasing the refrigerant, should I opt for one that is just refrigerant or one that refrigerant and includes oil? What about one that includes refrigerant, oil, and leak sealer?

3) What oil is used? PAG or Ester? If PAG, which viscosity (low,med,high)?

4) I had this in mind to say to the service rep "I believe there is a leak in the High side pressure hose, there is some oil residue on it, but would appreciate you checking out the other components and giving me an estimate for repairs". That sound reasonable without them thinking they can easily take advantage of me and also any guides on price of the high pressure hose I think might need to be replaced.

The high-side hose that tends to go is the short one from the compressor to the condenser. Part number for a 2000 model is 92490-7B411, list price is $83. When mine went I could clearly see where oil had leaked from the point where the metal portion joined the rubber portion and the rubber hose was dark with oil.

Replacing it was a piece of cake, I just released what little pressure was left in the system from the low side line using the Schrader valve near the brake vacuum booster, then did a quick swap of the high side line. The less time the system is open, the better. It's just a couple of bolts.
(Yes, I know, you're not supposed to vent the system to the open atmosphere, but it had done most of the venting on its own already).

The oil is Nissan A/C System Lubricant PAG Type R, part number KLH00–PAGR1, 6.8 oz total in the system. I added one of these just to be safe and replace any missing oil:
http://www.id-usa.com/product.asp?CID=34&PID=108

I did not draw a vacuum on the system when I recharged it, but you really should to remove the air from the system. Mine seems to be running fine though. I added the oil charge can (including 1 oz of R134A), then let it take what it wanted to of the refrigerant cans. It took about almost two 13 oz. cans, which jives with the 21.16-24.69 oz. capacity.
Just get refrigerant only, NOT the kind with the oil and refrigerant together. I don't think I even saw any of the combo type that had the PAG oil in them, they were all ester.

Brent

Thanks a ton! I might end up doing this myself and even evac it I can find a friend with a vac pump and a little know-how.

Just so I'm clear, you said the oil is Nissan A/C System Lubricant PAG Type R and that 6.8 oz total in the system and you added one to be safe. You link to a 2oz bottle. Was that just for example purposes or did you only use 2oz for a specific reason?

Also is all PAG oil Type R compatiable? Just curious.

Thanks again, that should help alot.

I used one 2 oz. can of oil, which also added 1 oz. of R-134A (3 oz. total in the can).

Compatible? Should be, PAG oil is PAG oil. I don't know what "type R" means where Nissan is concerned with regards to PAG oil, probably means "refrigerant" or may refer to the weight.
Odds are that I really didn't lose enough oil to warrant adding more, but I figured better safe than sorry. Might have more like 8 oz. total in the system now for all I know.

Yeah, I wasn't sure how much oil I should consider adding if I end up replacing the hose myself.

I figured since I've had this leak for awhile I should add more than just 2oz but still am unsure how much to add.

If I end up vac sucking it, would that require the full amount to be replaced?

Sorry I have so many questions.

The vacuum should not draw out much if any of the oil.
I highly doubt you've lost much if any oil. You would see evidence of it if you had. As I recall, I didn't see any anywhere but on the hose itself.