Nissan Dealership Refilled AC/Heatpump and Compressor mysteriously dies

[knightmb]

To give this some context, recently I wanted to recharge the refrigerant levels in my Leaf. I couldn't take it to any "generic" auto maintenance place because they did not have any HFC134a to source for a recharge. So, I had to take it to a Nissan Dealership instead. :?
To make a long story short, they did an evac and refilled the system with R-134A and while running it, the compressor mysteriously died and will no longer work. I knew something was wrong as the compressor worked literally the day of me bringing it in for maintenance. Before I would leave the dealership, I wanted to speak with the Tech that worked on my Leaf and ask him/her why they did not put the HFC134a (and ND-Oil 11) as it says on the sticker under the hood. He said their documentation only showed that it needed R-134A and that was it. I asked if he was referring to the "non-heatpump" systems that just have an AC only system and he said it's the same procedure for all of them.
I have not tried to turn on the system since returning from the dealership, but I'm fairly certain the wrong refrigerant was put in and no oil probably was not good for it either. :roll:

The tech notes on my paperwork is as follow:

EVAC AND RECHARGE R134A * RECHARGE R134A

EVAC AND RECHARGE OF AC SYSTEM IS COMPLETE, HOWEVER, AC STILL DOES NOT BLOW COLD AIR, AC COMPRESSOR DOES NOT ACTIVATE *REQUESTING DIAG LABOR TIME TO DIAGNOSE CONCERN

I didn't make a scene about it and just got all the contact information for the service manager, dealership, etc. I think my next step is to contact Nissan Corp about it but I figured someone here knows a lot more about Leaf heatpump systems than me and can give me some general information about whether they did this completely wrong or does the Nissan tech documents actually say this is the way to recharge the system in a Leaf?

 

[knightmb]

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.

 

[WetEV]

https://en.wikipedia.org/wiki/1,1,1,2-Tetrafluoroethane

R-134a and HFC134a are the same thing.

 

[LeftieBiker]

If the oil is always separate from the refrigerant, then their failure to add oil makes this more a 'slow motion failure' that could work ok for a while, then die for real. There is probably enough residual oil in the system (I don't think it evaporates like moisture when they pull a vacuum) to keep it going for a little while...

 

[knightmb]

https://en.wikipedia.org/wiki/1,1,1,2-Tetrafluoroethane

R-134a and HFC134a are the same thing.

R134a
Molecular formula: CHF2CHF2, molecular weight: 102.03 boiling point: 26.26 C, the critical temperature: 101.1 C, the critical pressure: 4067 kpa.

HFC134a
Molecular formula: CH2FCF3, molecular weight: 102.03, boiling point: 26.1 C, critical temperature , 101.1 C critical pressure, 4010 kpa

R134a and HFC134a are two different substances, but their physical properties are very similar.

Since R134a is being phased out, I suppose I go to HFO-1234yf :lol:
https://en.wikipedia.org/wiki/2,3,3,3-Tetrafluoropropene

 

[knightmb]

If the oil is always separate from the refrigerant, then their failure to add oil makes this more a 'slow motion failure' that could work ok for a while, then die for real. There is probably enough residual oil in the system (I don't think it evaporates like moisture when they pull a vacuum) to keep it going for a little while...

I think that may be the issue as well now that I was able to confirm that the compressor is still working and not dead. The R-134a vs HFC134a debate aside, it might work with one or the other just fine, probably not both mixed together for efficiency reasons.

The only reason I'm a little upset about the dealership is that I went through a lot of people, talked to the Leaf tech, etc. to make sure they were going to refill it with HFC134a before I brought it in. Granted, it was still working just fine before I brought it in, just not as well in extreme conditions of Heat or Cold. Now that the HFC134a has been removed and replaced with R134a, the system is basically not working at all except for just a small amount that you can measure with a electronic thermometer. The dealership also lied about the "compressor won't start anymore" and wanted to do an expensive full work up of the AC/Heatpump system.

So my guess, they evacuated the entire system, probably took most of the ND-Oil 11 with it and just refiled with straight R134a and then called it a day. Maybe someone later came back to try it out and noticed that it's working terrible compared to when I brought it in and tried to blame it on a "mysterious compressor failure, need to do more work" before I told them no way and wanted to come get it.

 

[wwhitney]

R134a
Molecular formula: CHF2CHF2, molecular weight: 102.03 boiling point: 26.26 C, the critical temperature: 101.1 C, the critical pressure: 4067 kpa.

HFC134a
Molecular formula: CH2FCF3, molecular weight: 102.03, boiling point: 26.1 C, critical temperature , 101.1 C critical pressure, 4010 kpa

No. R134a and HFC134a are the same things. The entry you have above labeled R134a gives the molecular formula of R134 / HFC134 (no a after it). No idea if the rest of the data you quoted is correct or not.

Cheers, Wayne

 

[knightmb]

No. R134a and HFC134a are the same things. The entry you have above labeled R134a gives the molecular formula of R134 / HFC134 (no a after it). No idea if the rest of the data you quoted is correct or not.

Cheers, Wayne

You are correct, my info was wrong on the molecule chain.

HFC-134a is actually C2H2F4
https://www.chembk.com/en/chem/HFC-134a
https://www.ncbi.nlm.nih.gov/books/NBK207609/

 

[wwhitney]

HFC-134a is actually C2H2F4

Both R-134 / HFC-134 and R-134a / HFC-134a are C2H2F4, but they are different isomers. R-134 / HFC-134 is CHF2 - CHF2 (two fluorine atoms bonded to each carbon). While R-134a / HFC-134a is CH2F - CF3 (one carbon has 3 fluorine bonds, one carbon has just one fluorine bond).

Cheers, Wayne

 

[knightmb]

Both R-134 / HFC-134 and R-134a / HFC-134a are C2H2F4, but they are different isomers. R-134 / HFC-134 is CHF2 - CHF2 (two fluorine atoms bonded to each carbon). While R-134a / HFC-134a is CH2F - CF3 (one carbon has 3 fluorine bonds, one carbon has just one fluorine bond).

Cheers, Wayne

You might be the perfect person to ask this question then. Why does the government refer to it as HFC-134a but then another name of R-134a is used when referring to automobiles. Why the confusion of using two different names for the same thing? Yeah, maybe off topic, but I am curious. :mrgreen:

 

[wwhitney]

You might be the perfect person to ask this question then.

No idea on that question. I just knew that there is a system for naming refrigerants and related fluorochlorohydrocarbons, but I had to look up the details.

Cheers, Wayne

 

[SageBrush]

Why does the government refer to it as HFC-134a but then another name of R-134a is used when referring to automobiles. Why the confusion of using two different names for the same thing? Yeah, maybe off topic, but I am curious. :mrgreen:

Isomers can vary in physical characteristics.

As for your car -- just because the compressor is pulling current does not mean that the pump is operating as intended

 

[knightmb]

As for your car -- just because the compressor is pulling current does not mean that the pump is operating as intended

Oh, that is certainly the issue right now. It can produce cold air, but is limited to only 750 watts of power oddly enough. I've never seen a compressor fail that way before and as far as I could research, have not found anyone online that has a working AC compressor that is weirdly limited to 750 watts of power either. :lol:

I already know what the dealership would "like" to do, replace the entire system for a lot of money. :lol:

 

[GerryAZ]

Why did you originally request a recharge? Was the compressor doing anything funny? The hermetically sealed heat pump should not leak unless there is a piping leak some where because it has no shaft seal like a conventional automotive compressor. Since it is drawing way less power than expected (assuming 750 W with desired temperature set to 60F on a warm day), it is likely filled with the wrong refrigerant, not filled with sufficient refrigerant, or not filled with the proper amount of the correct oil. Oil is not compressible so it takes up some of the volume in the system which indirectly makes the refrigerant operate at a higher pressure (for the same amount of refrigerant).

 

[knightmb]

Why did you originally request a recharge?

Loss of efficiency, wasn't cooling as well as it did the previous year. Can't tell much of a difference when using heat mode in winter because the PTC heater always makes up for the difference. When it's hot and you need AC, then you can tell the difference.

Was the compressor doing anything funny?

Everything sounded fine before, so I figured it was low or getting low on refrigerant. I know that no system is perfect, a little is going to leak out over time and use. I figured since I'm racking up thousands of miles every month, I'm just wearing the system out faster than normal.

The hermetically sealed heat pump should not leak unless there is a piping leak some where because it has no shaft seal like a conventional automotive compressor. Since it is drawing way less power than expected (assuming 750 W with desired temperature set to 60F on a warm day), it is likely filled with the wrong refrigerant, not filled with sufficient refrigerant, or not filled with the proper amount of the correct oil. Oil is not compressible so it takes up some of the volume in the system which indirectly makes the refrigerant operate at a higher pressure (for the same amount of refrigerant).

That is useful info to know because I wondered myself if the compressor went bad and maybe also leaking, but after they did the evac and replaced the refrigerant, the compressor (according to the tech) would not even start. When I got the Leaf back, I had some test setup to see what was going on. I turned on the AC first (it was a warm day of about 78F) and the compressor came on right away, so I thought to myself, hmm, seems to be running. I drove it around with a temperature probe in the vents to measure temperature and it was making cooler air but was limited to only 750 watts of power according to LeafSpy even when set to 60F on the dash. I knew something was up because I've seen it hit 3,000 watts of power to get the cabin air down to 60F quickly before the power starts to decrease, etc.
Finally drove back to my house and opened the hood to listen to it run and it sounded very different. It sounded like it was running at a much higher speed than normal. :shock:
After the test, I went ahead and shut everything down, haven't used AC since then because I don't want to cause anymore damage if this can be fixed.
The higher "speed" of the compressor does concern me, it's not normal as I've been listening to it for years, so I know what it sounds like when it's running normally.

 

[SageBrush]

Why did you originally request a recharge?

Loss of efficiency, wasn't cooling as well as it did the previous year.

How much power would it pull ?

 

[knightmb]

Why did you originally request a recharge?

Loss of efficiency, wasn't cooling as well as it did the previous year.

How much power would it pull ?

It would max out at 1,500 watts. Depending on the cabin temperature you set it for and how hot it was outside, it would work on warm days but on hot days, it wasn't enough to cool the cabin down quickly without lowering the windows to vent the heat first. On hot days, 1,500 watts just wasn't enough cooling if you are directly in the sun versus under some shade.

 

[knightmb]

Does anyone have access to the Nissan Docs that detail the procedure for charging the refrigerant on a Leaf with a heat pump system or troubleshooting issues like the compressor running faster than normal?

 

[SageBrush]

Does anyone have access to the Nissan Docs that detail the procedure for charging the refrigerant on a Leaf with a heat pump system or troubleshooting issues like the compressor running faster than normal?

That really does sound like not enough refrigerant

 

[knightmb]

Does anyone have access to the Nissan Docs that detail the procedure for charging the refrigerant on a Leaf with a heat pump system or troubleshooting issues like the compressor running faster than normal?

That really does sound like not enough refrigerant

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

Sounds like my entire system needs to be evaced again to start over and fill it correctly oil and refrigerant wise.