a/c not blowing cold air

[rbjtech]

Hi all,

So my a/c has not been working for a while - so I'm trying to fathom out why it is not producing ANY cold air.

I have the Auto Air/Con HVAC control.

If I press the A/C button the following happens -

- AC Compressor clutch engages and I can see it spinning the compressor.
- Aux/Electric fan does not come on.
- Idle rises slightly.

High/Low AC pipes appear to get 'warm' but this may simply be heat soak from the engine.

The system has been recently pressure checked, fully purged and re-charged professionally with an automated machine - apparently the original pressure was very close to what it should be - so I am assuming there are no leaks.

I can turn on the Aux fan with the Foxwell and it spins at what I assume is Max speed. I can also make the fan work at Max by unplugging the High side a/c pressure sensor. This reads as 5v when unplugged, 1.7v when the a/c is on.

My understanding is the Aux fan is not essential for the a/c to produce 'some' cooling effect but I have also run the car at cruising speed with the a/c on - but it does not make any difference, so the fan not turning on is not my primary concern atm.

As the compressor is working (and not turning off) I believe this means all systems are 'go' but no cold air.

Should the pipes entering the Evaporator (through the firewall) be hot on entry (liquid) and cold on exit (gas) ?

Any thoughts please on what to look at next ? Thanks.

edit - Updating my own thread ...

So it looks like I have a Carlsonic Kansei CSV717

So I guess the next thing to check is if the compressor is working - it's engaging just fine, but can it engage but still not pump effectively ?

[andrewwynn]

Not sure when they started using the variable clutch but you can't fill the freon without a working clutch.

I suspect either the clutch or the variable compressor.

Foxwell will read the evaporator temp so poll that data. It takes a bit to find where that info is hiding.



Very strange the EVAP warmer than heater cores we are driving about 75 and temp set to 71 on the dash.

I'll Have to do the measurement on my car to compare.

[upallnight]

Originally Posted by andrewwynn

Not sure when they started using the variable clutch but you can't fill the freon without a working clutch.

I suspect either the clutch or the variable compressor.

Foxwell will read the evaporator temp so poll that data. It takes a bit to find where that info is hiding.



Very strange the EVAP warmer than heater cores we are driving about 75 and temp set to 71 on the dash.

I'll Have to do the measurement on my car to compare.

His HVAC servicer used a machine that pumps the refrigerant into the system, most likely through the high side port since you can pump the liquid refrigerant through that port. A working compressor is not required to fill the system. The system is filled by weight and not lowside/high side values on the gauges.

The HVAC service person should had verified the lowside and highside pressure after the system was recharge. You need to find out what these pressure are in order to determine the problem. Could be the compressor or could be a bad expansion valve.

[upallnight]

Originally Posted by rbjtech

Hi all,

So my a/c has not been working for a while - so I'm trying to fathom out why it is not producing ANY cold air.

I have the Auto Air/Con HVAC control.

If I press the A/C button the following happens -

- AC Compressor clutch engages and I can see it spinning the compressor.
- Aux/Electric fan does not come on.
- Idle rises slightly.

High/Low AC pipes appear to get 'warm' but this may simply be heat soak from the engine.

The system has been recently pressure checked, fully purged and re-charged professionally with an automated machine - apparently the original pressure was very close to what it should be - so I am assuming there are no leaks.

I can turn on the Aux fan with the Foxwell and it spins at what I assume is Max speed. I can also make the fan work at Max by unplugging the High side a/c pressure sensor. This reads as 5v when unplugged, 1.7v when the a/c is on.

My understanding is the Aux fan is not essential for the a/c to produce 'some' cooling effect but I have also run the car at cruising speed with the a/c on - but it does not make any difference, so the fan not turning on is not my primary concern atm.

As the compressor is working (and not turning off) I believe this means all systems are 'go' but no cold air.

Should the pipes entering the Evaporator (through the firewall) be hot on entry (liquid) and cold on exit (gas) ?

Any thoughts please on what to look at next ? Thanks.

edit - Updating my own thread ...

So it looks like I have a Carlsonic Kansei CSV717

So I guess the next thing to check is if the compressor is working - it's engaging just fine, but can it engage but still not pump effectively ?

The lowside pipe should be cold and the highside pipe should be hot.

That's were knowing the low and high pressure come into play

[andrewwynn]

I realized the by weight possibilities after posting and goes to show you how some methods have distinctive advantages.

As the compressor and dryer etc wear the ac cycle will not work perfectly to spec which is where some seat of pants experience comes In handy.

Having AC problem today with wife’s x5 which I was able to diagnose using foxwell while wife was driving

•1 on hvac guy should have done actual high/low side pressure test and determine if the problem is in the compressor or expansion valve etc.

[rbjtech]

Thanks all - yes it was professionally filled and they didn't even start the car when doing the purge and refill which surprised me - it took about 45 mins from start to finish. It was only when they did start the car that they realised it was not cooling. The good news was that they did not charge me for the re-gas as it did not work .. the bad news is a bit of R&D suggests it's my variable compressor which is likely stuck and not creating any pressure. I'll look at the evap temps but I'm pretty certain it's the compressor .. thanks again guys.

[FellowsheepTech]

Went through a month of troubleshooting very similar, though my A/C would come on intermittently when driving. I can tell you it will not cool at idle if the aux fan is not running.

I had a new aux fan that tested good like yours (could activate from tool & by unplugging pressure switch). Turned out that new Amazon fan was incompatible with DME. Replaced it with another new one (PartsGeek I think), and bingo.

I should look up the thread & link it, but...had "intermittent" & "out of ideas" in subject.
I do still have an issue with the variable compressor, but can "make" it work by revving the motor up to 5k, so it's not urgent.

[X5StayinAlive]

Hi rbjtech,

I just saw your Post and I thought I'd jump in with my similar experience with my 2004 X5 E53 4.4i AC system. I posted my questions about my problem on here, and on other assorted X5 E53 group forums. Advice varied from replace AC compressor, to replace Everything. Or let a shop do it. Here is a link to my Post from September 30, 2019.

https://xoutpost.com/bmw-sav-forums/...y-problem.html

I hope I pasted the link properly.

My AC mystery was Why did my AC system with No leaks and proper 134a charge cool like a meat locker all day at idle, but Stops all cooling once 2000RPM is exceeded. Pressures go from near perfect, to static-like Hi-Low sides near equal around 100PSI and no cooling. Dropping the RPM's after 2000RPM Never restores cooling or return of pressure differential.(Revving to 5000RPM as some suggested had no effect either.) AC Clutch Never disengages. Car off overnight and engine back to ambient temp, and AC will cool Great again..... But only up to 2000RPM.
This scenario just really bothered me. A mechanical system Broken cannot heal itself. So I started research into Calsonic-Kansei and their CSV717 "VARIABLE DISPLACEMENT" AC Compressor. Key Words there. It is Not displacement controlled externally via either electronic circuit, or even mechanically. So Where is it's Displacement controlled from?? A little part called the "MT2280 Pressure Control Valve". I was all set to buy a NEW AC compressor, evaporator, filter/dryer, etc. But......
I decided to take a chance on the cheapest version of that valve from my local Auto Zone. The "Santech MT2280" for $14.99 plus tax. Pics included.
Please be Sure to evacuate your r134a Before removing the circlip holding this valve into the bottom of the CSV717. I used Brake Cleaner spray to make things as dirt free as possible in case this actually worked. Ohhhhh, and did I mention yet that I Did NOT have to remove the AC compressor from the X5 to do this? I did it all in the driveway with the X5 up on 2 metal ramps giving access to the compressor. I used my crappiest old pairs of circlip pliers to bend them into 'contort' position to get the circlip off, then back on with the new one. ***Warning*** Even evacuated, your AC compressor is Still under held pressure internally inside the compressor! So when you pry and coax this little round nub out, get ready for a Pop of some 134 and compressor oil. (Always eye protection. And some rags handy.) I lubed the new valve's O-rings with new PAG oil to insert. About 6 attempts in, I got the new circlip retainer to stay in. Even with horrific heat that day (08/07/20) and not the best of working conditions, the whole MT2280 new replacement valve took me about 20 minutes. Then 20 minutes of steady vacuum pull to check for leak down. All Perfect. Then 90+ minutes of vacuum pump (because very hot and humid day. Extra Suck always Good. lol). Then proceed with no rush, mostly gas vapor r134a to 440 grams (0.97lbs).
By now, you know where my story is going. I bought this car in August of 2017 for $350. (The abusive owner used it as his contractor pickup truck. A whole other story. Didn't run, and pretty rough.) LOTS of sweat equity into this X5. But I Never could enjoy driving it in NJ because you Need Air Conditioning in your car here. And the AC evaporator is needed in rain and cold for interior window defogging.
So, the Results: My 209K Mile E53 X5, for the First Time since owning it (and probably years before me), has a Perfectly working AC System. At ALL engine RPM's. I went from hating this car and nicknaming it the "Xcrement5", to absolutely Love driving it now. It's a BMW, so of course, It leaks oil near everywhere. But now with the AC 'mystery' solved (by me... yeah. I'll take those props! lol), I'll get on the oil leaks. And doing the trans service fluid, filter, bridge seal, etc.
Here are a few pictures. I went with a subtle but clear lean to red from BMW blue on logos. And shades of metallic gray and varied textures. I know style is subjective. But I'm pretty happy. If any interest by this group, I'll do a story board post of my resurrecting this X5. I am Still well under $1000 for All I have done to date. And that $1k Includes my $350 purchase price
I hope this info can help you. I found nothing on the internet about this issue with the Calsonic's. But an Easy 2+2=4 for me after going to the Calsonic website and seeing How their AC compressors actually work. A small perk of the general 'Covid can't go out anywhere' time to use to explore on the Internet.
Best To You and Yours.
Stay Safe & Healthy.
And Hopefully Cool & Comfy now ;-)
Michael C. In Brick, NJ USA


https://photos.google.com/photo/AF1Q...0PMiVfxnFaJfNr


https://photos.google.com/photo/AF1Q...EDQWuHrtt43d5a


https://photos.google.com/photo/AF1Q...ZadYnSEyecg3e4


https://photos.google.com/photo/AF1Q...kFaLZpwXXhawaK


https://photos.google.com/photo/AF1Q...Jt-LwAafFy2xwj


https://photos.google.com/photo/AF1Q...M12MsGOEqy8DqZ


https://photos.google.com/photo/AF1Q...koZdwuGqLifVKU


https://photos.google.com/photo/AF1Q...ZrrziCuJAf38Wm

[andrewwynn]

that's a GREAT post. Sounds like something *I* would do

[trhaverstock]

Originally Posted by X5StayinAlive

Hi rbjtech,

I just saw your Post and I thought I'd jump in with my similar experience with my 2004 X5 E53 4.4i AC system. I posted my questions about my problem on here, and on other assorted X5 E53 group forums. Advice varied from replace AC compressor, to replace Everything. Or let a shop do it. Here is a link to my Post from September 30, 2019.

https://xoutpost.com/bmw-sav-forums/...y-problem.html

I hope I pasted the link properly.

My AC mystery was Why did my AC system with No leaks and proper 134a charge cool like a meat locker all day at idle, but Stops all cooling once 2000RPM is exceeded. Pressures go from near perfect, to static-like Hi-Low sides near equal around 100PSI and no cooling. Dropping the RPM's after 2000RPM Never restores cooling or return of pressure differential.(Revving to 5000RPM as some suggested had no effect either.) AC Clutch Never disengages. Car off overnight and engine back to ambient temp, and AC will cool Great again..... But only up to 2000RPM.
This scenario just really bothered me. A mechanical system Broken cannot heal itself. So I started research into Calsonic-Kansei and their CSV717 "VARIABLE DISPLACEMENT" AC Compressor. Key Words there. It is Not displacement controlled externally via either electronic circuit, or even mechanically. So Where is it's Displacement controlled from?? A little part called the "MT2280 Pressure Control Valve". I was all set to buy a NEW AC compressor, evaporator, filter/dryer, etc. But......
I decided to take a chance on the cheapest version of that valve from my local Auto Zone. The "Santech MT2280" for $14.99 plus tax. Pics included.
Please be Sure to evacuate your r134a Before removing the circlip holding this valve into the bottom of the CSV717. I used Brake Cleaner spray to make things as dirt free as possible in case this actually worked. Ohhhhh, and did I mention yet that I Did NOT have to remove the AC compressor from the X5 to do this? I did it all in the driveway with the X5 up on 2 metal ramps giving access to the compressor. I used my crappiest old pairs of circlip pliers to bend them into 'contort' position to get the circlip off, then back on with the new one. ***Warning*** Even evacuated, your AC compressor is Still under held pressure internally inside the compressor! So when you pry and coax this little round nub out, get ready for a Pop of some 134 and compressor oil. (Always eye protection. And some rags handy.) I lubed the new valve's O-rings with new PAG oil to insert. About 6 attempts in, I got the new circlip retainer to stay in. Even with horrific heat that day (08/07/20) and not the best of working conditions, the whole MT2280 new replacement valve took me about 20 minutes. Then 20 minutes of steady vacuum pull to check for leak down. All Perfect. Then 90+ minutes of vacuum pump (because very hot and humid day. Extra Suck always Good. lol). Then proceed with no rush, mostly gas vapor r134a to 440 grams (0.97lbs).
By now, you know where my story is going. I bought this car in August of 2017 for $350. (The abusive owner used it as his contractor pickup truck. A whole other story. Didn't run, and pretty rough.) LOTS of sweat equity into this X5. But I Never could enjoy driving it in NJ because you Need Air Conditioning in your car here. And the AC evaporator is needed in rain and cold for interior window defogging.
So, the Results: My 209K Mile E53 X5, for the First Time since owning it (and probably years before me), has a Perfectly working AC System. At ALL engine RPM's. I went from hating this car and nicknaming it the "Xcrement5", to absolutely Love driving it now. It's a BMW, so of course, It leaks oil near everywhere. But now with the AC 'mystery' solved (by me... yeah. I'll take those props! lol), I'll get on the oil leaks. And doing the trans service fluid, filter, bridge seal, etc.
Here are a few pictures. I went with a subtle but clear lean to red from BMW blue on logos. And shades of metallic gray and varied textures. I know style is subjective. But I'm pretty happy. If any interest by this group, I'll do a story board post of my resurrecting this X5. I am Still well under $1000 for All I have done to date. And that $1k Includes my $350 purchase price
I hope this info can help you. I found nothing on the internet about this issue with the Calsonic's. But an Easy 2+2=4 for me after going to the Calsonic website and seeing How their AC compressors actually work. A small perk of the general 'Covid can't go out anywhere' time to use to explore on the Internet.
Best To You and Yours.
Stay Safe & Healthy.
And Hopefully Cool & Comfy now ;-)
Michael C. In Brick, NJ USA


https://photos.google.com/photo/AF1Q...0PMiVfxnFaJfNr


https://photos.google.com/photo/AF1Q...EDQWuHrtt43d5a


https://photos.google.com/photo/AF1Q...ZadYnSEyecg3e4


https://photos.google.com/photo/AF1Q...kFaLZpwXXhawaK


https://photos.google.com/photo/AF1Q...Jt-LwAafFy2xwj


https://photos.google.com/photo/AF1Q...M12MsGOEqy8DqZ


https://photos.google.com/photo/AF1Q...koZdwuGqLifVKU


https://photos.google.com/photo/AF1Q...ZrrziCuJAf38Wm

These links to the photos are all dead (404 not found error). I'd be eternally grateful if you reposted please as I am about to take this on as I have narrowed things down to this as a possible culprit and it's worth the $20 gamble. Thanks!