2008 Altima Not Cooling

[jtupper]

Please recall that you do not have to have a full charge to find your leak. One can will do

Understood. The last can I added had a dye in it so hopefully that will aid in finding the source of the leak. The sniffer shows that it has been delivered so I should have more data to report tonight. Appreciate all the help.

[JohnHere]

Not only can you not get out all the refrigerant contained in a can, as tbirdtbird mentioned, but some cans also don't contain a full 12 ounces to begin with. So it's really difficult to gauge a correct charge by putting in one full can and just a little bit more out of a second can. You can't properly gauge a charge by pressures alone, either.

The best way, of course, is to weigh-in the charge using a precise refrigerant scale or an RRR machine. It's especially important to get the right amount in there, particularly with the system in your car that holds so little refrigerant, as you noted. With systems like this one, an ounce or two too little or too much can make a profound difference in cooling performance.

[jtupper]

Well, pressures are not at zero. The static pressure with the car off is 80 low/ 100 high. With the car running and AC on max (compressor engaged) is 102 low/ 37 high. I'm unable to find a leak with the sniffer. Thoughts?

***EDIT*** Fun Fact: There is dye and what I can only assume is compressor oil all over the bottom of the compressor.

[JohnHere]

Did you have an approximate full charge in the system when you recorded these pressures? If so, it looks to me like the compressor is shot.

[jtupper]

Did you have an approximate full charge in the system when you recorded these pressures? If so, it looks to me like the compressor is shot.

I honestly have no clue. The AC was working great for the first couple of weeks, then quit cooling. I added probably a can and a half of freon with dye and it cooled again for a couple of days, then quit cooling again. With there being dye on the compressor, I assume that freon must have leaked out as well, no?

I still have a half can of freon. Should I add it and see if it cools. Wouldn't that rule out the compressor or not?

[JohnHere]

Yes, where refrigerant has leaked out, you'll usually find oil and, in this instance, UV dye. From what you said, it looks like the compressor is your culprit. I wouldn't bother with adding any more refrigerant.

If you replace the existing compressor with a new unit rather than a rebuilt, which I strongly suggest, the manufacturer will probably require replacing the condenser and receiver/dryer at the same time to maintain the new-compressor warranty.

[jtupper]

okay, I might be kind of a dummy. I had the hoses hooked up backwards, but in my defense, the instructions on the case are clearly wrong. It states to hook the red hose to the low side and blue to the high. I knew it didn't make sense. I switched them and now I'm getting 40/low and 100/high with the engine running and AC on max. compressor appears to be running.

[JohnHere]

Tim, the Forum sponsor, can get you whatever you might need at a good price.

[JohnHere]

Those instructions with the gauges are wrong, all right. The quick connectors are different sizes, too, so I wonder how they even hooked up to the car...unless the manufacturer switched those as well.

With 100 PSI on the high side and oil and dye all over the compressor, it's not only not pumping very much but also leaking like a sieve from who-knows-where. It could be a bad front seal or even a cracked case.

[jtupper]

Okay, so it looks like I need a compressor, condenser, drier and o-rings. I'm also replacing the discharge line because I found some dye pretty high up on that line. It could be blow back, but I'd rather be safe than sorry.

Is it necessary to replace the TXV? It's mounted in the firewall and looks like a PITA to change out.