Air con regas on hybrid expert required!

[Davey Blueeyes]

My car is a RX400h, 2008. I had the condenser replaced a month of so ago and it obviously needed to be regassed, which was done and all has been well since, good news given the weather! 

However it seems they used the PAG oil, rather than the ND-11 oil. I'm now familiar with this issue and I understand the consequences (I'm hoping the whole car won't become live!) but realistically what's the best way to deal with this? Does the whole cooling system need replacing?? It has been mentioned! Or can just the compressor be replaced and the system flushed? 

Plus no need to speculate on the garages culpability, they are long standing family friends and the young fella just got it wrong with the wrong machine and they will do whatever is needed to put it right. 

Right now, the air cons lovely! But I know we are a month or so from it failing. 

[iwonder]

It doesn't need replacing, just needs a thorough drain. A recovery will only draw 5-15g of oil. I would get them to remove condensor and compressor to drain and refill with correct oil.
Regas and add oil that was taken out during recovery.

[Herbie]

It's documented that as little as one percent contamination with PAG oil can damage the motor winding insulation.

If you're very, very lucky a thorough flushing of the whole system with either some sort of electrical contact cleaner and/or the correct oil may be enough to avoid a catastrophy. However, if the motor windings have been sat in PAG oil for a month as it seems they have, then that damage may already have started and may well be irreversible by now.

The compressor motor is a 500V three-phase unit so you really don't want insulation breakdown to occur.

Maybe get the compressor out and send the motor away for a safety inspection where they'll do insulation resistance tests?

EDIT: I don't know whereabouts you live in Hampshire but a couple of motor repair/rewind places include https://www.solentrewinds.co.uk/ and also https://electricmotorrewind.co.uk/index.html so it may be worth a phone call at least. Google has a few other places listed in case these are nowhere near you.

[iwonder]

The hybrid system already check itself for shorts. When the compressor fails due to incorrect oil, the hybrid system shuts down and you cantt even start the car unless you disconnect the compressor.

[Davey Blueeyes]

3 hours ago, Herbie said:

It's documented that as little as one percent contamination with PAG oil can damage the motor winding insulation.

If you're very, very lucky a thorough flushing of the whole system with either some sort of electrical contact cleaner and/or the correct oil may be enough to avoid a catastrophy. However, if the motor windings have been sat in PAG oil for a month as it seems they have, then that damage may already have started and may well be irreversible by now.

The compressor motor is a 500V three-phase unit so you really don't want insulation breakdown to occur.

Maybe get the compressor out and send the motor away for a safety inspection where they'll do insulation resistance tests?

EDIT: I don't know whereabouts you live in Hampshire but a couple of motor repair/rewind places include https://www.solentrewinds.co.uk/ and also https://electricmotorrewind.co.uk/index.html so it may be worth a phone call at least. Google has a few other places listed in case these are nowhere near you.

Thanks Herbie, that's brilliant. I'm actually on the Isle of Wight but I'm currently away with the car and back 30th Aug. Hopefully I can take it in and they can send it off. I'm hoping that if the worst comes to the worst a new compressor and flushing the rest will do the job. As said, condenser is new. So far the cheapest compressor I've found is just under a grand but I'm not paying for it! 

The biggest worry is being stranded in deepest darkest Cornwall while I'm away! I'm just looking for a pragmatic and decent solution

[Davey Blueeyes]

3 hours ago, iwonder said:

The hybrid system already check itself for shorts. When the compressor fails due to incorrect oil, the hybrid system shuts down and you cantt even start the car unless you disconnect the compressor.

Being stranded in the next two weeks is the biggest worry! Hopefully I'll make it back okay! 

[iwonder]

Being stranded in the next two weeks is the biggest worry! Hopefully I'll make it back okay! 

Don't use air con until it's fixed and you will be fine

[Barmac]

Not sure this helps, but might be worth checking. Had our RX400h regassed last week, and given the concern over the correct lubricant and possible contamination I took it to my local Lexus dealer. I was talking to the technician who did the work, and explained to him my concern that ND11 was used, even though my son is a technician at a BMW dealership. Apparently BMW use a PAG oil in their hybrids. The Lexus technician said that it was possible to obtain a PAG lubricant that was suitable for hybrids, but they used ND11 as it "refreshed the seals" in the system. It would appear that a PAG variant can be used on hybrids without damage. I obviously can't confirm this, but it might be worth checking.

[Herbie]

1 hour ago, Barmac said:

The Lexus technician said that it was possible to obtain a PAG lubricant that was suitable for hybrids,

None of my research shows this to be true, at least for Lexus/Toyota.

Maybe other marques have different systems that are compatible with PAG but I really don't see how that could be because PAG oil is hygroscopic and has a low dielectric, meaning that it's conductive, whereas ND-11 is a high dielectric and non-conductive.

1 hour ago, Barmac said:

but they used ND11 as it "refreshed the seals" in the system.

All oils keep the seals lubricated, whether PAG or ND-11.

Maybe the Lexus tech you spoke to was a new starter  🙂

[Britprius]

Herbie above is correct. It may be that BMW use an engine driven compressor, or uses a different design of compressor drive system. 
At minimum your system should be flushed, new dryer fitted, and compressor removed so that it can be totally drained. The system should then be refilled with the correct ND11 oil, and R134A refrigerant. Also insist that if the compressor fails due to electrical current leakage to ground at any time in the future it will be replaced free of charge.
The AC should not be used while the wrong lubricant is in the system.
The problem is that using the wrong oil does not cause immediate failure, but can happen months down the line as the oil attacks the winding conformal coating, and internal wiring insulation. The compressor is not normally prone to electrical failure, and tend to fail due to mechanical issues. If it does fail electrically the wrong oil is virtually certain to be the reason for the failure.

It may be helpfull to you to find how to disconnect the compressor electrically just in case the compressor does fail. As the car will shut down completely if a high voltage leak is detected by the cars safety system.

John.

[Mihanicos]

I agree with everything the learned members have already stressed in detail.

The problem is that the compressor oil is carried by the refrigetant in every part and pocket within the system's equipment . Even with systems incorporating an oil separator an oil film is still left everywhere. Verifying that every trace of the oil has been removed from the system prior to charging in view of the work involved, equipment and time needed and the fact that bad workmanship will not be obvious immediately, I would say that it would take a very dedicated professional, perfectionist from another world to do the job right.

Chris.

[m4rkw]

19 hours ago, Davey Blueeyes said:

So far the cheapest compressor I've found is just under a grand but I'm not paying for it! 

Be careful buying something that significant very cheaply. Sometimes the cheapest way out is the most expensive way in.

[Davey Blueeyes]

1 hour ago, Mihanicos said:

I agree with everything the learned members have already stressed in detail.

The problem is that the compressor oil is carried by the refrigetant in every part and pocket within the system's equipment . Even with systems incorporating an oil separator an oil film is still left everywhere. Verifying that every trace of the oil has been removed from the system prior to charging in view of the work involved, equipment and time needed and the fact that bad workmanship will not be obvious immediately, I would say that it would take a very dedicated professional, perfectionist from another world to do the job right.

Chris.

So what is the way forward? Would it be to rip out the entire air con system and replace everything? This must have happened before, I'd love to know how others have dealt with this, I can't be the first! 

The garage are good eggs and it was a genuine (and expensive!) error on their part and they are happy to rectify to my satisfaction. I'm away, which complicates matters a tad but are meeting with a specialist air con chap early next week and the cars already booked back in on the 1st Sept for whatever is advised to be done. 

I know it's my car but I kinda feel for them!

But mostly thank you all for taking the time to reply, I'm really appreciative of it

[Britprius]

3 minutes ago, Davey Blueeyes said:

So what is the way forward?

If you feel you wish to reduce the costs to your garage I would go the route outlined in my post. However with the stipulation also in my post of a replacement compressor if it should fail electrically in the future.
The correct way would be to have the complete system replaced, but the cost would probably run to as much as £5000 with labor for stripping out the dashboard to replace the evaporator buried within.

John.

[m4rkw]

This is what I would do:

1) Get an independent trusted qualified technician to provide an opinion on the appropriate way to correct the situation

2) If their opinion is anything other than a complete system replacement, get a second opinion

If two qualified techs agree that it can be done without replacing the entire system, go ahead but as John said insist on some kind of parts+labour written warranty for the compressor. Otherwise, full system. Imagine how galling it would be if you agree to let them go the cheaper route and have the compressor fail two and a half years down the line. They'll be able to claim that it was unrelated and you'll be left out of pocket.