What is wrong with my AC?

nissan
altima

#1

Before I spend money on an AC compressor, which has been recommended (sort of), I would like to see if anyone has any suggestions about what could be going on with it:

It’s a 2015 with 34K miles on it and it appears to be working fine during the first hour or so of operation (cooling at all times although it appears to take longer to do so when it’s hot outside) but then after driving an extended amount of time and going idle, it blows hot muggy air but then cools back down the minute I start driving. Everything has been checked and the evaporator coil has been replaced and so far the consensus is that the pressures are off and not where they should be and that the compressor has a valve seal leak, which I’ve been told can be fixed without replacement. Is there anything else that could be going on with this ac system?? I don’t want to spend the money on the compressor just to have overlooked something less costly. Thanks!


#2

Because you have already had it checked over by a professional and they don’t have to replace the compressor, just repair it, I would agree with their diagnosis. We can’t see and hear the car nor the pressures measured so it is tough to contradict. If you are concerned about the diagnosis, you could take it to get a second opinion.

BTW, 3 years old is very early to have AC problems. Considering that Nissan’s have a 3 year, 36,000 mile warranty I hope you are doing this at the dealer 'cause it could be free.


#3

Thanks, it’s out of warranty as it’s technically been in service for 4 years now (as of June).

This was the third opinion actually, but all haven’t been 100% certain that replacing the compressor will actually solve the issue, but they’re not sure exactly what else it could be, so that’s been the main suggestion thus far. The original issue was with the fan relay, but that’s been fixed (after the first mechanic screwed everything else up) and the evaporator coil replacement seemed to make the AC cooler… and now it’s just the temperature at idle that’s concerning. Just wish I had a guarantee that replacing the compressor would fix this.


#4

evap coil? inside the dash? as in $$$?


#5

I suppose, I don’t know for sure, he just checked for clogs, etc… and suggested replacing that first before the compressor replacement. And it did make the system cool better overall, but yesterday I drove about an hour at interstate speeds and then exited and when I got in traffic it started blowing warm muggy air, and did so for the rest of time I was in traffic… I got back on the interstate and it cooled fine again. When I picked it up last week, he had suggested the compressor pressures were still off but wanted to see what happened if I drove it for a few days.


#6

The compressor magnetic clutch is what comes to mind. To test it, open the hood and turn the a/c on.The belt should spin the compressor pulley firmly without slipping.If it slips, check the belt condition and tension.If the belt tension is fine you will need to replace the magnetic clutch.


#7

tech cannot find leak. system is not working since pressures are off. replace evap coil. it should work immediately and not settle down after a day or too. thats crap. tech does not know what the problem is


#8

I’ve read a few places to check the battery to see if it’s charging everything well… Is that even a possibility in this situation?


#9

Correction: It was the expansion valve