2004 X5 E53 4.4i A/C System Mystery Problem

[X5StayinAlive]

Hi group. This is my first post. Sorry it's such a long one. Thanks in advance for any help. I'm hoping someone has crossed this stream before and can guide me further. I have a 2004 X5 E53 4.4i with 207k miles. Seller said It was heading to the scrap yard if I didn't buy. Lots of my sweat equity into this thing. I'll post picture sets of my restoration and light custom touches in another post. But my question of the day is about the A/C system. It didn't work when I bought it. It had an unknown R134a charge that never leaked or lost pressure. I've just dived into resuscitating it. Pulled a perfect 30" vacuum that it held for 2 days. No leaks. Charged it with 440 grams of R134a. Also added lube agents. NO Stop Leak added. There are No leaks. Manifold Gauges read 55psi low side and 210psi high side. 24 Degrees F at center dash vents. This is with direct sun and 85+ ambient at Sea Level in NJ. Sounds Great, right?? It is great until engine goes over 2000rpm. Then the low side goes to about 80psi and high side about 110psi. Bye bye cooling. It's not an overheat issue. It will idle all day from cold start to full engine temp if left alone in the hot sunshine and chill the inside great. Drive it and pass 2000rpm.... No more AC cooling. And it does Not start cooling again once 2000rpm is crossed, and then back to idle again. Needs to be left off overnight. Then cools perfect again until next 2000rpm crossing. I changed out to a new TXV valve thinking that was it because slightly slow return to equilibrium when shutting off system while working well. Exact same issues. No ugly black death oil residue anywhere I can see. Static pressures in morning when off overnight are equal and temperature appropriate. Compressor clutch never seems to cut out.

When I installed that new TXV it helped, but didn't cure. I did not replace the desiccant, as the system has never been opened except for quick TXV swap. Then immediate 90+ minute vacuum. Powerful 2 stage 8cfm vacuum pump. Good gauges. No leaks.
Radiator, condenser, oil cooler all clear and squeaky clean. No obstructions.
INPA shows no error faults. Electric fan and AC clutch engage in use, and on software command from INPA. But if I force AC into 2000rpm+ failure mode, fan will not run from AC calling for it. Only engine temp activates fan if needed.
See how this gets tedious? I'm trying to be thorough, but I have to be missing Something.
Another thought to maybe ponder...
This system takes a really Small amount of R134a. 440 grams +/- 10 grams. I am filling this by using a pretty good digital food scale on tare setting to read out Net grams. On a 4 pound system, close enough is good enough. On this E53 requiring 0.97lbs (440 grams) I could easily be over, or under the 10 gram margin of error. Can overcharge or undercharge trigger this failure mode??
And Why does it stay stuck in near equal low and high side pressures until a full overnight rest?? Then back to crazy icy cold. Is there some safety valve / sensor I'm not aware of tripping and staying tripped until car and system is all back to ambient temp again?

Some have recommended a new compressor. I also suspected the compressor. But if it is as they say that it goes weak at higher RPM's, why doesn't cooling come back again at low rpm's or idle? I just drove it again tonight after posting my problem. It blew ice cold 23 degrees at center vent the whole time up to the magic 2000 rpm's of death mark. I even shut the car off in a parking lot for 10 minutes after that happened. No recovery of system cooling. Since it has a magnetic clutch, I'm assuming it is Not a variable displacement type. Nor has any internal pressure regulating valves. I listened to the compressor with a mechanics stethoscope and it didn't sound like rocks in a blender. Just what I thought was normal pump sounds pre the 2000 rpm curse. I haven't had the opportunity to listen with steth after the failure mode occurs yet.
This is my first actual 'car' since losing everything in the SANDY Flood of 2012. (I only have a very used 2001 Ford E250 van since so I can get around and work too.) So I'm not in a financial position to throw parts at it. Is there a definitive test to say Ahhahh! Definitely AC Compressor!? Or whatever else it could be???
I have to admit that this 2004 old tech car designed in the mid to late 90's is frustrating to diagnose.
What am I missing?

Ideas??? Please 🤔🙄😳
Thanx!

[upallnight]

Originally Posted by X5StayinAlive

Hi group. This is my first post. Sorry it's such a long one. Thanks in advance for any help. I'm hoping someone has crossed this stream before and can guide me further. I have a 2004 X5 E53 4.4i with 207k miles. Seller said It was heading to the scrap yard if I didn't buy. Lots of my sweat equity into this thing. I'll post picture sets of my restoration and light custom touches in another post. But my question of the day is about the A/C system. It didn't work when I bought it. It had an unknown R134a charge that never leaked or lost pressure. I've just dived into resuscitating it. Pulled a perfect 30" vacuum that it held for 2 days. No leaks. Charged it with 440 grams of R134a. Also added lube agents. NO Stop Leak added. There are No leaks. Manifold Gauges read 55psi low side and 210psi high side. 24 Degrees F at center dash vents. This is with direct sun and 85+ ambient at Sea Level in NJ. Sounds Great, right?? It is great until engine goes over 2000rpm. Then the low side goes to about 80psi and high side about 110psi. Bye bye cooling. It's not an overheat issue. It will idle all day from cold start to full engine temp if left alone in the hot sunshine and chill the inside great. Drive it and pass 2000rpm.... No more AC cooling. And it does Not start cooling again once 2000rpm is crossed, and then back to idle again. Needs to be left off overnight. Then cools perfect again until next 2000rpm crossing. I changed out to a new TXV valve thinking that was it because slightly slow return to equilibrium when shutting off system while working well. Exact same issues. No ugly black death oil residue anywhere I can see. Static pressures in morning when off overnight are equal and temperature appropriate. Compressor clutch never seems to cut out.

When I installed that new TXV it helped, but didn't cure. I did not replace the desiccant, as the system has never been opened except for quick TXV swap. Then immediate 90+ minute vacuum. Powerful 2 stage 8cfm vacuum pump. Good gauges. No leaks.
Radiator, condenser, oil cooler all clear and squeaky clean. No obstructions.
INPA shows no error faults. Electric fan and AC clutch engage in use, and on software command from INPA. But if I force AC into 2000rpm+ failure mode, fan will not run from AC calling for it. Only engine temp activates fan if needed.
See how this gets tedious? I'm trying to be thorough, but I have to be missing Something.
Another thought to maybe ponder...
This system takes a really Small amount of R134a. 440 grams +/- 10 grams. I am filling this by using a pretty good digital food scale on tare setting to read out Net grams. On a 4 pound system, close enough is good enough. On this E53 requiring 0.97lbs (440 grams) I could easily be over, or under the 10 gram margin of error. Can overcharge or undercharge trigger this failure mode??
And Why does it stay stuck in near equal low and high side pressures until a full overnight rest?? Then back to crazy icy cold. Is there some safety valve / sensor I'm not aware of tripping and staying tripped until car and system is all back to ambient temp again?

Some have recommended a new compressor. I also suspected the compressor. But if it is as they say that it goes weak at higher RPM's, why doesn't cooling come back again at low rpm's or idle? I just drove it again tonight after posting my problem.It blew ice cold 23 degrees at center vent the whole time up to the magic 2000 rpm's of death mark. I even shut the car off in a parking lot for 10 minutes after that happened. No recovery of system cooling. Since it has a magnetic clutch, I'm assuming it is Not a variable displacement type. Nor has any internal pressure regulating valves. I listened to the compressor with a mechanics stethoscope and it didn't sound like rocks in a blender. Just what I thought was normal pump sounds pre the 2000 rpm curse. I haven't had the opportunity to listen with steth after the failure mode occurs yet.
This is my first actual 'car' since losing everything in the SANDY Flood of 2012. (I only have a very used 2001 Ford E250 van since so I can get around and work too.) So I'm not in a financial position to throw parts at it. Is there a definitive test to say Ahhahh! Definitely AC Compressor!? Or whatever else it could be???
I have to admit that this 2004 old tech car designed in the mid to late 90's is frustrating to diagnose.
What am I missing?

Ideas??? Please 🤔🙄😳
Thanx!

If you are blowing 23F at the center vent. your system is low on refrigerant. Automotive refrigerant are not designed to go below 32F. 32F is when water freezes and the condensate on the evaporator starts to freeze and turn to ice. Run the system long enough and the evaporator is covered with ice preventing air from flowing through the evaporator and releasing the heat into the evaporator.

I would suggest that you bring it to a shop that can pull a vacuum and recharge by weight with an AC machine designed for this. The cost shouldn't be more than $100.00. Could be the Tare setting for a kitchen scale is more accurate when it comes to adding weight instead of subtracting weight as I assume you are doing when it comes to adding refrigerant into the system.

[X5StayinAlive]

Hi Upallnight. Thanks for the reply. My IR digital thermometer is a very old, non-laser type unit that is meant for close, non angle of incidence readings. I took the Lowest reading as my basis. It may have read off of one of the evaporator fins to catch that number. Other readings against the black plastic vents are in the low 30's. But not repeatable. So for measurement consistency, I used the lowest number as my guiding benchmark. I will be getting a proper automotive A/C Vent dial or digital thermometer to measure the actual Air Temperature soon. None were available at Auto Zone or Advance Auto. So Amazon it is.
On the kitchen scale for accuracy, I took the known quantity of the Net 12oz / 340grams as my "By Weight" reference Walmart can to see if my yellow line hose with air purged R134a in it would decrease by -340 grams when can was no longer cold and felt empty. It was pretty close to that with 520 grams gross, then Zeroed out and going down to -336 grams. I estimated there may be a few grams unaccounted for in the hose lines with 10 combined feet of Yellow to Blue. Hence holding back the 'maybe' 4 grams. Then I did the same procedure for the next can remainder amount.
I am Not trying to defend my methods. I totally agree that a closed loop automated R134a machine is the best way to go. My point is I wasn't guesstimating or sloppy like adding 3 big cans of Arctic Freeze with the little blue gauges into a non evacuated system.
The question I'm hoping to find the answer to is WHY A/C failure completely repeatable every time above 2000rpm?? And it Never recovers to working again upon lowering the rpm's after that triggering. What changes after an overnight cool down that Re-Sets it to work Really well again?
I did another little experiment last night. I put the cold, unused all day car to ignition position 2 and Shut Off the A/C snowflake button Before engine start. Then I drove to a nearby, long and sparse traffic road. I put the X on Cruise control in manually selected 4th gear and set cruise for 2500 rpm. While very steady at 2500rpm, I pressed the "MAX" button for A/C. It blew about ambient temp for maybe 5 seconds. Then started to feel the AC cooled air happening. Not frigid like at idle or under 2000, but definitely AC from evaporator. That only lasted about 5 seconds worth. Then slowly but steadily went back to no AC feeling by hand. I then quickly went back to regular "D" mode drive which put me back to about 1300 or so rpms. No recovery.
Here are suggestions from other sites that I posed my issues to with my thoughts or replies in brackets after each:
1) "Your compressor is weak. Works at low rpm. Can't keep up at high rpm. Replace compressor" (If my compressor is weak at high rpm, why doesn't cooling or pressures Resume again when under 2000rpm?)
2) "You have a stuck expansion valve." (As I stated before, I just put in a new TXV. No change in failure mode above 2000rpm. If I shut off system pre failure, the Low and High sides equalize as they should.)
3) "You have an 'Air Bubble' that only forms from the 2000 rpm+ pressures that blocks the system. It remains formed from hardened refrigerant oil around it blocking passage. When temperature and pressures drop overnight, system works again. It could reach your compressor in Solid Form and destroy it." (I have no knowledge base to comment on this one. The person suggesting it does refrigeration systems. Not car AC. But he believes this can carry over to car systems.)
4) "You have air or moisture in your system. Bring it to a shop." (I am on here looking for DYI cures. Both to learn them, and share with others. I have a brand new Robinair 2 stage, 8cfm 1HP vacuum pump and brand new, pretty good, non leaking 4 port gauges. I am confident in the quality of the vacuum created.)
5) Similar to your suggestion. "Have a quality shop with a closed loop machine do an evacuate and precision 440 gram refill." (I am in total agreement that this is the Best way. But those computer automated machines weren't even existing in the 90's when this E53 was conceived. I'm guessing there are lots and lots of E53's out there that get the Auto Zone / Pep Boys / Walmart cure-in-a-can R134a package with the little blue gauges that every know-nothing YouTuber with a cellphone camera posts success videos of.)


I am Very Thankful, and Respect all of the kind people like you and others who took time out to suggest courses of action. But aside from the trapped "Air Bubble" theory, nothing soo far addresses this non-resetting shut down above 2000rpm. And the No Additional Action by me full recovery to cold A/C the next morning.
I hope this additional new info is useful. Can I be the Only E53 owner with this exact issue????



I see my thread here doesn't draw many comments compared to 2 or 3 sentence long threads. I Know I put Lots of words in a world of 140 characters or less. Lol

My scientific background nature loves details, accuracy, and repeatable procedures. So forgive me for TMI

[upallnight]

Originally Posted by X5StayinAlive

Hi group. This is my first post. Sorry it's such a long one. Thanks in advance for any help. I'm hoping someone has crossed this stream before and can guide me further. I have a 2004 X5 E53 4.4i with 207k miles. Seller said It was heading to the scrap yard if I didn't buy. Lots of my sweat equity into this thing. I'll post picture sets of my restoration and light custom touches in another post. But my question of the day is about the A/C system. It didn't work when I bought it. It had an unknown R134a charge that never leaked or lost pressure. I've just dived into resuscitating it. Pulled a perfect 30" vacuum that it held for 2 days. No leaks. Charged it with 440 grams of R134a. Also added lube agents. NO Stop Leak added. There are No leaks. Manifold Gauges read 55psi low side and 210psi high side. 24 Degrees F at center dash vents. This is with direct sun and 85+ ambient at Sea Level in NJ. Sounds Great, right?? It is great until engine goes over 2000rpm. Then the low side goes to about 80psi and high side about 110psi. Bye bye cooling. It's not an overheat issue. It will idle all day from cold start to full engine temp if left alone in the hot sunshine and chill the inside great. Drive it and pass 2000rpm.... No more AC cooling. And it does Not start cooling again once 2000rpm is crossed, and then back to idle again. Needs to be left off overnight. Then cools perfect again until next 2000rpm crossing. I changed out to a new TXV valve thinking that was it because slightly slow return to equilibrium when shutting off system while working well. Exact same issues. No ugly black death oil residue anywhere I can see. Static pressures in morning when off overnight are equal and temperature appropriate. Compressor clutch never seems to cut out.

When I installed that new TXV it helped, but didn't cure. I did not replace the desiccant, as the system has never been opened except for quick TXV swap. Then immediate 90+ minute vacuum. Powerful 2 stage 8cfm vacuum pump. Good gauges. No leaks.
Radiator, condenser, oil cooler all clear and squeaky clean. No obstructions.
INPA shows no error faults. Electric fan and AC clutch engage in use, and on software command from INPA. But if I force AC into 2000rpm+ failure mode, fan will not run from AC calling for it. Only engine temp activates fan if needed.
See how this gets tedious? I'm trying to be thorough, but I have to be missing Something.
Another thought to maybe ponder...
This system takes a really Small amount of R134a. 440 grams +/- 10 grams. I am filling this by using a pretty good digital food scale on tare setting to read out Net grams. On a 4 pound system, close enough is good enough. On this E53 requiring 0.97lbs (440 grams) I could easily be over, or under the 10 gram margin of error. Can overcharge or undercharge trigger this failure mode??
And Why does it stay stuck in near equal low and high side pressures until a full overnight rest?? Then back to crazy icy cold. Is there some safety valve / sensor I'm not aware of tripping and staying tripped until car and system is all back to ambient temp again?

Some have recommended a new compressor. I also suspected the compressor. But if it is as they say that it goes weak at higher RPM's, why doesn't cooling come back again at low rpm's or idle? I just drove it again tonight after posting my problem. It blew ice cold 23 degrees at center vent the whole time up to the magic 2000 rpm's of death mark. I even shut the car off in a parking lot for 10 minutes after that happened. No recovery of system cooling. Since it has a magnetic clutch, I'm assuming it is Not a variable displacement type. Nor has any internal pressure regulating valves. I listened to the compressor with a mechanics stethoscope and it didn't sound like rocks in a blender. Just what I thought was normal pump sounds pre the 2000 rpm curse. I haven't had the opportunity to listen with steth after the failure mode occurs yet.
This is my first actual 'car' since losing everything in the SANDY Flood of 2012. (I only have a very used 2001 Ford E250 van since so I can get around and work too.) So I'm not in a financial position to throw parts at it. Is there a definitive test to say Ahhahh! Definitely AC Compressor!? Or whatever else it could be???
I have to admit that this 2004 old tech car designed in the mid to late 90's is frustrating to diagnose.
What am I missing?

Ideas??? Please 🤔🙄😳
Thanx!

That is a BAD assumption. Some variable compressor also had a magnetic clutch. Next time the AC is not cooling, you need to connect a set of gauges to the low side and high side ports. What are the readings? Port reading will help you pinpoint what is the problem.

[upallnight]

Didn't see that you posted the low side and high side reading when there was no cooling. With a low side of 80 and a high side of 110 I would say that your compressor is faulty.

Even if you find out that you have a variable displacement compressor, I wouldn't try repairing it. I would just replace it.

[iansanderson]

sounds like a classic Calsonic compressor failure. Other issue they have is not blowing cold right away, then working normally after a few minutes of driving. The variable clutches in them are junk. I would replace the compressor with a low-mileage used one if funds are tight, and replace the dryer if you can

[g300d]

^Yes it sounds like a variable displacement compressor problem.

Some discussion on it in this thread. Hope it helps.
https://xoutpost.com/bmw-sav-forums/...-ac-delay.html