I'm still new to the Mini (we picked it up last month for our daughter) and I've been trying to sort out the few things I've found that need attention. One of them is that the AC does not blow cold air.

What I have verified:

• I did have to add a little refrigerant, but the low and high side readings are now reading correctly (when engine running, AC on max, recirc On)
  • Low side pressure - 35-36psi (about 75deg F outside)
  • High side pressure - 190psi, climbing to 275psi and then the cooling fan kicks in for a bit and the pressure drops...and then the cycle repeats.
  • With this condition, there is still warm (ambient-ish) air coming out of the dash vents.
• When the vehicle is off, the high and low static pressures stablize and hold...so there doesn't seem to be a major leak at play in the system.
• The AC clutch coil is engaging when the AC is turned on, and the compressor is turning, so it's not a bad AC clutch coil. I read a lot of threads about replacing that, and I wish my issue was that straightforward. I've replaced those AC clutch coils on my VWs and Dodge Ram before when they've failed.
• The AC "snowflake" green LED does not blink when On (I saw this referenced in other threads, but this seems to indicate a fan fault or low refrigerant level)

So, from some other threads here, I am leaning towards this being a clogged or non-functional expansion valve. I can order and replace that (and the receiver/drier, since the system will be opened), then pull a vacuum and re-charge the system.

Just looking for BTDT feedback, thoughts and advice - thanks!

 

What about the air temp flapper? Does the air coming out of the vents go full hot and then full cold? Maybe it’s sticking open and letting hot air mix with the AC cold air.

 

The components seem to be working. The presure difference between the low and high side suggest the ex. valve is working?

my guess: evacuate the system replace the dryer and recharge to spec

 

Do you have the auto or standard ac system?

 

@ssoliman , it is the Auto system (temp.display in the middle circle)

 

ok. you can run a diagnostic from the automatic ac panel. I'll send a link that has the how-to info.

Also, you can actuate and test the auto ac controls from inpa, if you have that setup. its a good place to start

 

link to more info. kind of a lot but its all there: https://www.northamericanmotoring.co...t-working.html

 

@ssoliman Thanks for the info! I was out of town over the long weekend, but will be diagnosing this issue further this week. I'll post my findings.

 

It's taking a little longer to get to the Mini to look at this (had some AC repairs on our 2001 Jetta to take care of - that's done now and was, thankfully, successful). I just ran the Automated Diagnosis, and no faults were reported (flashed "00"). But from reading through the other threads that were posted here, I'm wondering if blend door is off its hinges or something behind the dash. There was A LOT of wiring behind the radio from an aftermarket radio installation under the previous owner and maybe that snagged on the mechanism and put things out of whack. I'll have a look.

 

00 is good. At least it seems your control panel is good

 

Just to update...this isn't resolved, yet. Unfortunately I haven't had the time to dig further in to the diagnosis. The AC hasn't magically healed itself, either

I will close this out with a resolution, though.

 

Thanks for your follow ups here … looking forward to reading about your resolution … it's how this community helps each other learn

thanks !!

 

What does our mothers have to do with this :D

 

I'm in the middle of an alternator replacement and supercharger oil change (among other things), and I happened to notice THIS on the AC compressor wiring to the AC clutch solenoid...


So, now I'm not so sure that the AC clutch was really engaging...or if it was, was it slipping a lot because of a possible intermittent grounding of the signal wire. Wouldn't that blow a fuse, too?

I'm going to order up an AC clutch/solenoid kit and replace that while I have the front end apart.

 

Make sure you thoroughly clean the corrosion from around the center of the shaft on the compressor. (And back of clutch housing).

Also measure the resistance from the clutch housing to a known good ground once installed. Should read less than 10 ohms. If not, remove and keep cleaning. Higher resistance will likely cause it to heat that wire or be intermittent.

Gen 1 uses a integral ground as compared to Gen 2 that has a wired ground. Wish we could convert it to a Gen 2 style.

 

I've ordered this kit from eB@y: https://www.ebay.com/itm/264255184124

It does indicate that it will only work with the OEM AC compressor (which I believe ours is), but it looks like it is a revised version with a seperate grounding lead for the coil. I've sent a message to the vendor to confirm it is compatible with our car. I'll also clean the corrosion from the shaft and wipe it with contact grease before installing the new parts, just in case.

 

The alternator replacement (and all the additional items I decided to tackle while I had access) are done. I replaced the AC clutch/solenoid/coil, too. The AC clutch is definitely engaging the compressor when I call for AC, and the air out of the vents felt cooler than the outside temperature (but it's 60deg F here today, so a little hard to be positive). If we get a warmer day I'll double-check and post the results here. Worst case, that may not be until late Spring around here

One trouble point I did run into when reinstalling everything...the ear for the screw that secures the AC coil's connector broke when I tightened the bolt back down (and I was using a torque wrench so as not to over-tighten it, too). My fix was to tap the hole all the way through that section of the boss off of the compressor and then use a longer bolt to secure the connector.


When I removed the old AC clutch and coil, the back of the coil was pretty corroded, so a poor ground contact to the body of the compressor may have been a contributing factor to the problem. I used a wire wheel on a drill to clean face of the compressor, and then smeared a little contact grease over the surface before installing the new coil.

 

You can buy a reman compressor on eBay for around $100. I spent less than $200 and replaced everything (receiver, dryer, etc.) on my R53 and the system will freeze you out of the car. Your compressor looks like it's seen better days - start over.

 

...says the man living in TX If our vehicles see any sort of Winter weather around here, they start looking rough underneath, fast.

But your point is taken. It may just come down to what you suggest: replace the compressor, receiver/dryer, EVAP valve, etc. and re-charge. I will post the final updates/results, it just may be a while.

For this attempt, I went with replacing the obviously bad/damaged AC clutch coil/solenoid, as I have had luck with replacing those on my Dodge Ram and VWs to get the AC working again without having to crack open the system.

 

Ha! I agree that rust is not an issue in Texas but heat certainly is. A/C down here is not an option. It's a necessity especially when the thermometer hits 110 degrees in August and you need a glove just to touch the shift ****. Replacing all the A/C components was one of the first things I did after buying my MC40. Good luck.

 

Trust your diagnostics. If the gauges show proper high side pressure when you turn on the AC. And then it equalizes when you turn off the AC, well then the compressor is compressing.

Either something is preventing the refrigerant from circulating through the system or something is preventing heat from being exchanged from the condenser or evaporator.

​​​​​​In my case the expansion valve was the problem which restricted the flow of the refrigerant. Luckily there was a whistling sound coming from the expansion valve to help me locate the problem. Like you, the gauges all showed proper readings when I tested. I've only ever fixed one AC issue though so it course it could be different for you.

My post history should have my experience.

​​​​​​

 

@BillyMac , thanks for the feedback! I had a look at your repair thread, as well.

It will be a while before it's warm enough here in Michigan to dig further into our AC's behavior, but I'll post back with any results at that time.

 

Hoo-boy...I have been a little delayed in tackling this.

I have the Mini on the lift to get it ready for Summer. Parts are slowly arriving, but I am determined to fix this AC issue.

I double-checked my HVAC control panel through the diagnostics menu (our 2005 Mini Cooper R52 S has the automatic climate control panel without the Off button, so the solution there is to press and hold the A/C (snowflake) and Fan+ buttons for 2-3s to reach that menu, instead of the Off and Fan+ for the other panels). The diagnostics are still clean - "00".

Then I started the car and turned the AC on and off - the AC clutch does engage when the AC switch is On. BUT, the radiator fan did not turn on. I can confirm that my low fan speed is not working, so I have a bad radiator fan resistor. I do have a good replacement fan assembly here, so I will tackle that.

But, when I plugged in that good radiator fan, it did not turn on either when the AC was engaged - so, I have other things to check, too. More diagnostics and feedback to come...

 

I've been in your situation; fixed ac clutch, fixed fan resistor, compressor was compressing and the system was air tight. Problem was the expansion valve. (this was a Mini R50 I daved from the scrapyard)

On my daily, an R53, the low fan was broken but the ac still performed well. What you will notice is that after a minute or so, after starting the car, the high fan will kick in very shortly, like 3 seconds. And this continues to happen every minute.

 

Thanks for that detailed feedback/experience! 👍

I already have a new Expansion Valve on-hand waiting to go in. The AC had never worked (blown cold) for us. My kids were in a minor accident with the Mini that damaged the front end, so I'm replacing the condenser and receiver/drier, too. I'll report back when everything is reassembled and tested.