A/C Question(s)

[Overlordexo]

Hey there all, A friend of mine recently had an issue with his 2012 Genesis 3.8L. His AC was working normally, then one day out of the blue is stops. He took it to the dealer, who informed him that his compressor had failed.

So, as he didn't want to pay what the dealership wanted to get it repaired, we ordered the compressor, condenser, TXV. I have spent the last few days removing all of the old components and lines - flushing everything out, reinstalling all new seals and reinstalling the new compressor/condenser/txv.

I then placed the system under vacuum for about an hour, closed the manifold and let the system sit for another hour. Vacuum remained at -30 (as per the manifold gauges). So with everything looking good and the system appearing to be sealed, i charged the system with R134a (22.9+0.88oz), noted that the compressor was engaged and refrigerant was flowing thru the system. After a few moments, I noticed my low side pressure beginning to dive, while the hi side pressure remained around 225 PSI. While the low side pressure continued to dive to around 10 PSI, the high side climbed to about 250 PSI.

So to me, that indicates some side of restriction on the suction side. The EVAP was completely clear when I flushed it. Could the TXV be faulty (even though it's new) and causing this?

I currently have the vehicle connected to my recovery machine to verify that there indeed is not a leak somewhere in the system. (By weighing the recovered r134a)

Or is there something else I'm missing?

Any thoughts, ideas, suggestions would be appreciated!

 

[jep604]

Quite possible you received a DOA part. I understand why your friend wanted to replace the critical parts in the A/C system but replacing 3 separate units makes the mystery worse. Stay tuned for the Genesis "Wizards" to offer their thoughts. Many intelligent folks on this forum.

 

[joegr]

Quite possible you received a DOA part. I understand why your friend wanted to replace the critical parts in the A/C system but replacing 3 separate units makes the mystery worse. Stay tuned for the Genesis "Wizards" to offer their thoughts. Many intelligent folks on this forum.

Those are the three parts that you have to replace if the compressor fails in such a way as to spread debris through the system.

 

[Gunkk]

My 2012 4.6 manual says the 22.9oz is (maximum) capacity, and instructs to add only 18oz when doing the initial charge (2nd screenshot).




Was compressor oil added to the system? And was the receiver/drier changed?

 

[Overlordexo]

My 2012 4.6 manual says the 22.9oz is (maximum) capacity, and instructs to add only 18oz when doing the initial charge (2nd screenshot).

View attachment 55049
View attachment 55048

Was compressor oil added to the system? And was the receiver/drier changed?

View attachment 55047

Hmm.. well that could indeed be where I have errored.. I recovered the r134 from the vehicle, the amount recovered was clearly above 18oz.. Tomorrow morning I will recharge with just 18oz and see if I get normal operation, or at least some operation. Thank you for this information. I will post an update with the results.

And yes, the compressor oil was drained, measured and refilled as per those instructions. I also added a bit of oil to the condenser as instructed. As for the receiver/dryer, that is part of the condenser is it not? (and that was just installed brand new). Am I missing it's location as being somewhere else?

 

[Gunkk]

Yeah the receiver/drier is the vertical tube attached to the condenser (pass side). Manual says dessicant needs to be changed, but perhaps the new one comes ready to roll?

 

[jep604]

Those are the three parts that you have to replace if the compressor fails in such a way as to spread debris through the system.

Did you mean as "not" to spread the debris in through the system?

 

[joegr]

Did you mean as "not" to spread the debris in through the system?

My meaning was that you must replace those parts if the compressor failure has [already] spread debris (tiny metal flakes) through the system.
You can't flush the condenser because if has parallel circuits.

 

[Overlordexo]

Yeah the receiver/drier is the vertical tube attached to the condenser (pass side). Manual says dessicant needs to be changed, but perhaps the new one comes ready to roll?

View attachment 55054

Okay, so finally the new TXV showed up. The system held vacuum while waiting for the part to show up. I swapped out the TXV, what I noticed is that at ambient temp on the NEW TXV, I could blow air through the lower evap port (smaller, high pressure feed line I'm assuming). On the old TXV, at ambient - the valve was completely closed.. So i'm fairly confident that the old TXV was not functioning properly.


All that remains is to charge the system with 18.1oz of r134a and see if I have proper operation.

I will post the results later this evening!

 

[Overlordexo]

Okay, so finally the new TXV showed up. The system held vacuum while waiting for the part to show up. I swapped out the TXV, what I noticed is that at ambient temp on the NEW TXV, I could blow air through the lower evap port (smaller, high pressure feed line I'm assuming). On the old TXV, at ambient - the valve was completely closed.. So i'm fairly confident that the old TXV was not functioning properly.


All that remains is to charge the system with 18.1oz of r134a and see if I have proper operation.

I will post the results later this evening!

Okay - Just a final update. It turns out it was indeed the stuck TXV causing the system to produce no cooling.

Recharged the system with 18.1oz of R134a and the system is cooling now. It seems a little weak, like it might be a bit undercharged but i'm really wary to add any more to the system. Once i get the front clip reassembled I'll go take it on the freeway and see how the cooling system performs.

But thanks for the insight guys, really appreciated.

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[Gunkk]

Glad you got it sorted!