Nissan Dealership Refilled AC/Heatpump and Compressor mysteriously dies

[SageBrush]

Would having too much compressor oil cause something similar to happen?

Sorry, beyond my pay grade. Gerry may have answered your question above.

Yeah, I had a similar thought about trying again. Can you find a competent dealership ?

 

[GerryAZ]

Disclaimer: I have no experience working on the LEAF A/C or Heat Pump systems (because I have had no problems so far).

The label under the hood on my 2019 SL Plus shows 0.85 kg (1.87 lbs) of HFC-134a, but does not show the total amount of ND-OIL 11. I did not take time to set up a portable DVD drive with my computer to check the service manual for my 2019 (which must run from the DVD), but the manual for my 2015 (which is just a PDF file) has a procedure for determining how much oil to add based on replaced parts. It is not clear how much oil would be removed by evacuation so it talks about measuring the oil removed. My guess is that just evacuation without replacing parts would not remove too much oil, but some. Can you find out if the dealer technician added any oil? Does the high pressure pipe get hot to touch and low pressure pipe get cold to touch when you run the compressor?

My experience with other A/C systems is that a little extra oil should not have much impact, but way too much oil will reduce cooling. I don't think extra oil would cause extra noise and should not cause the compressor to run fast since compressor speed is based upon discharge pressure. I think the compressor would run fast if refrigerant is low because the control system would try to build appropriate pressure based upon ambient temperature and desired interior temperature. If you think the abnormal compressor noise is just because it is running fast (not from lack of lubrication), then I would bet on low refrigerant. High pressure pipe slightly warm and low pressure pipe very cold to touch would also be indicative of low refrigerant.

 

[knightmb]

Can you find out if the dealer technician added any oil?

I do know the answer to this one, at least when I was there, the Leaf tech said their machine automatically adds the oil and refrigerant at the same time when refilling. I would take a guess that if the oil level was already good and an evac only removes the gas (not the oil), then it probably has twice as much? :?

Does the high pressure pipe get hot to touch and low pressure pipe get cold to touch when you run the compressor?

My experience with other A/C systems is that a little extra oil should not have much impact, but way too much oil will reduce cooling. I don't think extra oil would cause extra noise and should not cause the compressor to run fast since compressor speed is based upon discharge pressure. I think the compressor would run fast if refrigerant is low because the control system would try to build appropriate pressure based upon ambient temperature and desired interior temperature. If you think the abnormal compressor noise is just because it is running fast (not from lack of lubrication), then I would bet on low refrigerant. High pressure pipe slightly warm and low pressure pipe very cold to touch would also be indicative of low refrigerant.

I should be able to test this out tomorrow and report back. In my thoughts, it seems like it was filled with too much oil; it would be similar to a liquid pump where it's just spinning the oil around in the circle and since the oil is heavier than the gas, probably is just sitting in a "puddle" oil basically with the gas only having a small gap to compress through. I suspect the motor has a RPM limit on it and it's just too easy to spin in place without doing much compression on the gas. Since it's not doing as much work, it is using a lot less power just "spinning" in place I suppose. All theory of course.

 

[GerryAZ]

I think it would still be compressing refrigerant even if significantly over filled with oil so the compressor would sound normal speed. If their equipment does add oil (of the correct type) along with refrigerant, then it should not be low on oil. If low on refrigerant, then it would not build full pressure so the controls would run the compressor faster. Again, guessing because the only work I have done on my LEAFs' HVAC systems was to install a resistor on the 2011 to eliminate unnecessary resistance heater operation.

 

[knightmb]

If you think the abnormal compressor noise is just because it is running fast (not from lack of lubrication), then I would bet on low refrigerant. High pressure pipe slightly warm and low pressure pipe very cold to touch would also be indicative of low refrigerant.

I used my wife's Leaf to compare since we have the same Heatpump system. So they are both sitting at 60 psi when sitting idle all night and day time temperatures were 68F. I started my wife's Leaf first and noticed right away the pressure gauge makes a smooth dip in pressure and cold air comes out of the vents right away.

I then switch to mine, switch on the AC and the first thing I notice is that the pressure gauge needle is bouncing between 50 and 60 PSI at a very fast rate, almost a blur it's moving so fast. The high pressure pipe is kinda cold and the low pressure pipe is ambient temperature, doesn't feel to change temperature much.

Starting to seem like compressor might be bad unless that bouncing needle and pressure are signs of something else wrong? :?

[edit:] To add to this, I just tried switching between AC and Heat and the behaviors are not the same. Switching to heat resets the pressure to 60 psi like the pump is not even running, switch to AC attempts to do something (though it struggles with the pressure)
I'm starting to wonder if my problem is the reverse switch for the system? Is it stuck in a way where it won't run AC mode properly but cuts off the Heat mode (reverse) completely?

[edit2:] I will also be looking at the Air Conditioner Expansion Valve going bad since that also controls the flow of refrigerant to the compressor.

 

[GerryAZ]

Can you listen with a stethoscope for movement of the reversing valve when you switch between heat and cool? If the valve is moving, but not going fully to either position, that might explain the bouncing pressure gauge. You might even be able to hear it as the gauge bounces.

 

[Jbechtold]

Update for this Dealership saga :?

Now that I had time, it turns out the compressor is actually working just fine. I did the brave thing and turn on the AC today, had Leaf Spy running in case there was any more info I could gather. The compressor came on, I could see it using power in Leaf Spy and some "cooler" air was coming out of the vents. Not as cold as it was before, but there was a definite change in temperature from warm to cold air. I made sure to re-circulate so my temperature measures confirmed a drop and just didn't "feel" that way to me. I flipped it around to "warm" mode and watched again as power was being by the compressor to make warm air this time, so the reversing value must be working just fine.

So it turns out the compressor is working, dealership lied to me about that. :evil: My guess is having the "wrong" refrigerant is part of the "poor" performance of the system, just my theory anyway. I'm waiting to hear back from Nissan Corp about this and any useful (or technical) info I find out, I'll be sure to post it here for future people that may come up with the same issue.

Your problem was likely caused by the unnecessary servicing. I'm on my 5th Leaf. I NEVER to look any of them in for anything other than recalls or a warranty issue. Never let them open (and contaminate) the brake systems! They don't need new fluid unless you let them break that factory seal. Same goes for the ac.
Leafs need nothing but tires, ww wipers & fluid, and an occasional cabin air filter (do it yourself, it's easy). If you keep it long enough, you'll have to replace the 12v battery. If anything goes wrong after 4 years or so... Replace that first. It's likely the problem.
That's it. Don't take it anywhere; it will only lead to trouble.