[p1fm]

So, I have a problem with my AC not working correctly. Details as follows:
1) AC works fine for about 1 hour.
2) Then, around the 1 hour point, the air turns lukewarm, and after another 15 minutes, the A/C is blowing hot, outside-temperature air.
3) So... after shutting off the A/C (and running with the windows down), if I wait about 45 minutes - the A/C then works fine again.
4) Then, after about another hour, the same problem occurs - Air temp goes to lukewarm, then hot.
5) I notice that the time it takes for the A/C to start putting out warm/hot air depends on how hot it is outside. For instance - in the mornings when the outside temp is ~70-75, it takes closer to 2 hours for the A/C to stop working. But, when it's 80+ outside, the A/C works as described above.

Note: The refrigerant (R134a?) in the vehicle is the original refrigerant - it has not been purged/refilled.

Does anybody have any ideas what may be causing this? Any help/advice is most appreciated!

 

[Keith Wagner]

It would be a good idea to take it to a shop and get the A/C serviced.
At that age, the refrigerant is probably done, but also the accumulator/dryer is probably due for replacement.

 

[p1fm]

It would be a good idea to take it to a shop and get the A/C serviced.
At that age, the refrigerant is probably done, but also the accumulator/dryer is probably due for replacement.

Thanks! I will get that looked at!

 

[2016 Versa]

Sounds like the a/c system is freezing up and the time you leave the a/c off allows it to thaw and start blowing cold air again. Next time it does it before turning the a/c off pop the hood and look around you'll likely have accumulated ice on the a/c lines. The ice is caused by moisture that has somehow entered the a/c system and the ice prevents the freon from flowing through the system correctly. If I'm correct you need to have the system checked for leaks, repair any leaks, pull vacuum on the system then recharge to correct capacity of oil/freon.

 

[Cmak]

I recently bought a used 2014 Note and had a similar problem. I think it still needs a charge of AC coolant, but it started acting a little bit better when I added radiator fluid, which it was very low on.

 

[mthrasher16]

My 18 does this exact same thing. Not worth the cost or trouble to fix.

 

[tutti57]

The coolant level doesn't have any impact on the ac system, so something else must have happened, or it's placebo. If it was overheating, then it would shut off the compressor, but that's it.

It could easily be worth fixing, if all I needs is an exact vacuum, and recharge. You can get that done for around $100, and very well may fix the problem if there's moisture in the system or it has the wrong amount of refrigerant in it, both can cause this issue.

 

[p1fm]

So, I have a problem with my AC not working correctly. Details as follows:
1) AC works fine for about 1 hour.
2) Then, around the 1 hour point, the air turns lukewarm, and after another 15 minutes, the A/C is blowing hot, outside-temperature air.
3) So... after shutting off the A/C (and running with the windows down), if I wait about 45 minutes - the A/C then works fine again.
4) Then, after about another hour, the same problem occurs - Air temp goes to lukewarm, then hot.
5) I notice that the time it takes for the A/C to start putting out warm/hot air depends on how hot it is outside. For instance - in the mornings when the outside temp is ~70-75, it takes closer to 2 hours for the A/C to stop working. But, when it's 80+ outside, the A/C works as described above.

Note: The refrigerant (R134a?) in the vehicle is the original refrigerant - it has not been purged/refilled.

Does anybody have any ideas what may be causing this? Any help/advice is most appreciated!

So.... I took the car to a Nissan Dealership. The shop "ran the car for 2 hours and could not duplicate the issue". So, they didn't do a damn thing.

This is so frustrating! I am not IMAGINING this!

Anyhow, does anybody happen to know of a COMPETENT AC Repair service in the Atlanta Metro area?

 

[tutti57]

Competency doesn't have anything to do with it. If they couldn't reproduce it after two hours, the right thing to do is to give it back to the customer. You do not want them to make a guess with your money.

This is a good explanation.

 

[Desert Rodent]

I making the assumption that the dealership hooked up a set a manifold gauges and checked the high and low side pressure. Is that mentioned on the write up/paperwork??

The fact that the problem is intermittent and difficult to duplicate has me leaning towards the clutch in the compressor. On some compressors (I have worked on) the compressor clutch is shimmed so that when the power comes on & off it can engage & disengage properly, if the gap isn't right (within tolerance) the compressor clutch can't engage. This was an issue with an older Honda I had, years ago. It was intermittent as the metal expanded and contracted due to surrounding heat, thus the compressor clutch would sometimes work and sometimes not.

I don't know if Nissan uses a similar type of system for shimming the clutch, but as the compressor clutch wears, you have to remove a shim or put in a thinner one.

This is just a wild guess on my part. I will admit, I'm not very good with A/C systems.

 

[p1fm]

I making the assumption that the dealership hooked up a set a manifold gauges and checked the high and low side pressure. Is that mentioned on the write up/paperwork??

The fact that the problem is intermittent and difficult to duplicate has me leaning towards the clutch in the compressor. On some compressors (I have worked on) the compressor clutch is shimmed so that when the power comes on & off it can engage & disengage properly, if the gap isn't right (within tolerance) the compressor clutch can't engage. This was an issue with an older Honda I had, years ago. It was intermittent as the metal expanded and contracted due to surrounding heat, thus the compressor clutch would sometimes work and sometimes not.

I don't know if Nissan uses a similar type of system for shimming the clutch, but as the compressor clutch wears, you have to remove a shim or put in a thinner one.

This is just a wild guess on my part. I will admit, I'm not very good with A/C systems.

The tech I spoke with said they put temperature probes in the vents, ran the car for an hour - and it came out reading 38 degrees = on spec. No pressure test was done. Nothing else was checked.

 

[tutti57]

20-30* colder than ambient means it's working. You'll have to figure out what the conditions are when it's acting up. What the setting are exactly, are you moving fast or sitting still, ambient conditions, etc. Every detail.

 

[p1fm]

UPDATE: So, I ran the vehicle around Atlanta for about 2 hours and when the AC started blowing lukewarm, I took it back in to Nissan to show them that that I wasn't imagining this. The service advisor then told me that it would be $190 for a "diagnostic" of the AC system... and if they had to go further - like taking the compressor apart - that would be more $$$. And then, there's the parts cost on top of that....

So, after some thought... I have decided that mthrasher16 (comment above) has it right: Not worth the cost or trouble to fix.

 

[tutti57]

Any shop should be able to figure this out pretty easily. I'd just go to a different shop and have them do it.

 

[p1fm]

Any shop should be able to figure this out pretty easily. I'd just go to a different shop and have them do it.

I may consider taking it to an independent shop. My problem is with the Nissan Dealership: they want to charge me out the a$$ just to diagnose it. NOPE. I'm going to look into some independent A/C shops in Atlanta - that are reasonably priced

 

[tutti57]

It's probably one of hour of diagnosis at their hourly rate, which is standard procedure anywhere. You're bringing it there for a service for them to perform. The alternative is for them to not diagnose it, guess what the problem is, and spend your money putting parts in it until it's fixed.