Stock Problems/Issues Discussions related to warranty related issues and repairs, or other problems with the OEM parts and software for MINI Clubman (R55), Cooper and Cooper S(R56), and Cabrio (R57).

Air conditioner troubleshooting help

  #1  
Old 06-12-2019, 05:13 AM
samstoney
samstoney is offline
1st Gear
Thread Starter
Join Date: Oct 2018
Location: Just outside Boston, MA
Posts: 16
Received 0 Likes on 0 Posts
Air conditioner troubleshooting help

2013 Mini R56, IHKS, manual AC system. It suddenly stopped blowing cold air a month or so ago. I took it to a reliable shop, but one that does not have mini diagnostics equipment. So far they have replaced compressor, Evap valve, temperature sensor, and flushed the system several times; it still doesnít work. Reasonably good low and high pressure readings. Theyíve given up, saying (with a laugh, not seriously) that the car is defying physics: cold air should be blowing out.
So - Iím trying to do a bit of troubleshooting on my own. First off - is it worth it for me to get a scan tool of some sort do diagnose the IHKS? I hate to for this one project, and I havenít found a lot of info on just what I can see/test through the software. That said, I have nothing to go by to figure out what sensor is doing what, when - Bentley is useless in this case. Second, has anyone had similar issues and found a solution?

Thanks. Iíll post more data as i go today.
 
  #2  
Old 06-12-2019, 06:33 AM
samstoney
samstoney is offline
1st Gear
Thread Starter
Join Date: Oct 2018
Location: Just outside Boston, MA
Posts: 16
Received 0 Likes on 0 Posts
...just hooked a set of gauges to the system. 70f outside, 25psi Low side, 175 psi high side. No cold air.
 
  #3  
Old 06-12-2019, 06:50 AM
2012_R60
2012_R60 is offline
1st Gear
Join Date: Nov 2017
Posts: 45
Received 4 Likes on 4 Posts
Did they check if the heater is fully closed when you put the thermostat on max cold? If not then youíre reheating the cold air. An easy check to see if your AC system is working touch the suction pipe going into the evaporator at the firewall. Thatís the larger diameter pipe leaving the compressor. It should be freezing cold. If itís not then thereís something going on with your system. Are the condenser fans engaging correctly?
 
  #4  
Old 06-12-2019, 07:16 AM
samstoney
samstoney is offline
1st Gear
Thread Starter
Join Date: Oct 2018
Location: Just outside Boston, MA
Posts: 16
Received 0 Likes on 0 Posts
Great suggestion, IR thermometer shows 107 degrees on both pipes. Radiator fan seems to be kicking in/out normally, I wasn’t aware that there might be a separate fan. I’ll look in to that. I’m also double checking fuses/relays.
 
  #5  
Old 06-12-2019, 07:26 AM
2012_R60
2012_R60 is offline
1st Gear
Join Date: Nov 2017
Posts: 45
Received 4 Likes on 4 Posts
Just reread your initial post. So they havenít replaced the AC receiver drier?! This is mandatory whenever your changing compressor/evaporator valve! If your system is clogged you need to change the drier. I think the only downside for this in the mini the drier is integrated with the condenser. So that means you need to change the condenser itself.
 
  #6  
Old 06-12-2019, 08:14 AM
samstoney
samstoney is offline
1st Gear
Thread Starter
Join Date: Oct 2018
Location: Just outside Boston, MA
Posts: 16
Received 0 Likes on 0 Posts
A little history:

- December - installed a new engine (long story) at this time I installed new receiver/dryer/condenser. Brought to shop that vacuumed/filled the system, ac worked fine

- may - ac stopped blowing cold. Had same shop drain/refill, they suspected evap valve. Drained/replaced evap valve. System worked for a day or two then failed

- late May - replaced pressure switch, no changes.

- early June - replaced condenser with Chinese Amazon one. It did weird things - pressure would spike,then drop to nothing, spike, then drop to nothing...replaced with used Mini compressor.

Every time the system has been apart it has been sealed when open and/or only open for short time periods in low humidity weather. And every time it has been recharges it has been vacuumed/recharged with commercial service equipment by trained (non-mini) mechanics. I agree that, technically, the dryer should be being replaced every time, but I don’t think this sounds like a moisture issue

I’m increasingly suspecting electronics. I checked the condenser thermocouple inside the car today and it’s spot on, Im now going through all the connections/grounds.
 
  #7  
Old 06-12-2019, 08:38 AM
2012_R60
2012_R60 is offline
1st Gear
Join Date: Nov 2017
Posts: 45
Received 4 Likes on 4 Posts
Originally Posted by samstoney View Post
A little history:

- December - installed a new engine (long story) at this time I installed new receiver/dryer/condenser. Brought to shop that vacuumed/filled the system, ac worked fine

- may - ac stopped blowing cold. Had same shop drain/refill, they suspected evap valve. Drained/replaced evap valve. System worked for a day or two then failed

- late May - replaced pressure switch, no changes.

- early June - replaced condenser with Chinese Amazon one. It did weird things - pressure would spike,then drop to nothing, spike, then drop to nothing...replaced with used Mini compressor.

Every time the system has been apart it has been sealed when open and/or only open for short time periods in low humidity weather. And every time it has been recharges it has been vacuumed/recharged with commercial service equipment by trained (non-mini) mechanics. I agree that, technically, the dryer should be being replaced every time, but I donít think this sounds like a moisture issue

Iím increasingly suspecting electronics. I checked the condenser thermocouple inside the car today and itís spot on, Im now going through all the connections/grounds.
Unfortunately the receiver is very prone to clogging. I suggest you test the inlet and outlet temps if its accessible https://macsworldwide.wordpress.com/...r-service-tip/
 
The following users liked this post:
samstoney (06-12-2019)
  #8  
Old 06-12-2019, 04:11 PM
samstoney
samstoney is offline
1st Gear
Thread Starter
Join Date: Oct 2018
Location: Just outside Boston, MA
Posts: 16
Received 0 Likes on 0 Posts
Thats pretty interesting. I’ve been looking around at connections and haven’t found anything. Power seems to be getting to the compressor, and the clutch is engaging.

I’ve always assumed the receiver drier was a bypass sort of affair, Butm if I understand correctly from the post you’re linking to this can plug the system. That would explain a lot - a restriction smaller than the evap valve restriction would allow the compressor to pump at pressure, but w/o enough flow through the evap valve to cool.

That looks to be my next step.

Sam
 
  #9  
Old 06-12-2019, 05:56 PM
mkov608's Avatar
mkov608
mkov608 is offline
3rd Gear
Join Date: Feb 2009
Location: Pensacola, FL
Posts: 270
Received 28 Likes on 19 Posts
Plug in a scanner (an inesxpensive Foxwell NT520 would work) and pull up the evaporator coil temperature sensor; that parameter in under the DME menu under temperature sensors, live data.
 
  #10  
Old 06-12-2019, 06:36 PM
2012_R60
2012_R60 is offline
1st Gear
Join Date: Nov 2017
Posts: 45
Received 4 Likes on 4 Posts
Originally Posted by samstoney View Post
Thats pretty interesting. Iíve been looking around at connections and havenít found anything. Power seems to be getting to the compressor, and the clutch is engaging.

Iíve always assumed the receiver drier was a bypass sort of affair, Butm if I understand correctly from the post youíre linking to this can plug the system. That would explain a lot - a restriction smaller than the evap valve restriction would allow the compressor to pump at pressure, but w/o enough flow through the evap valve to cool.

That looks to be my next step.

Sam
Back in the day when I was a young lad I had a car A/C shop with my dad. All we did was car A/C. Itís been about 15 years since I worked on one professionally but Iíve worked on thousands of cars. The drier and the expansion valve have very small orifices. If thereís something in the system that blocked one it most likely blocked the other. We always changed both because it wasnít worth the gamble of going through what youíre going through now. My suggestion is if the drier is blocked go ahead and change the valve again. I know itís extra cost but youíve already thrown enough money to the problem itís worth the extra small cost now than risking leaving a blocked valve and have to rediagnose the problem.
 
  #11  
Old 06-13-2019, 04:27 AM
samstoney
samstoney is offline
1st Gear
Thread Starter
Join Date: Oct 2018
Location: Just outside Boston, MA
Posts: 16
Received 0 Likes on 0 Posts
Originally Posted by mkov608 View Post
Plug in a scanner (an inesxpensive Foxwell NT520 would work) and pull up the evaporator coil temperature sensor; that parameter in under the DME menu under temperature sensors, live data.
I pulled the actual evaporator sensor and tested it; itís good. This doesnít bar the possibility of a bad bit of wiring, but I donít think so. As things look now, power gets to the compressor, compressor engages and makes pressure, but no cold. Iím not ruling out electronics, but a system obstruction is the most likely culprit now, I think.
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
rfhamner
Stock Problems/Issues
5
09-25-2017 09:10 AM
nathanrw
Stock Problems/Issues
1
08-21-2017 01:57 PM
Blasbo
Stock Problems/Issues
12
04-21-2015 01:23 PM
kevin barrett
Stock Problems/Issues
8
05-14-2007 06:27 PM


Thread Tools
Search this Thread
Quick Reply: Air conditioner troubleshooting help


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: