This is a bit of a long post, but I'm hoping the info here will be of use in finding a solution.

Background - initial problem was no heat in winter, but A/C working; replaced DCCV, then had heat and also A/C; then, in summer the A/C would blow cold air for awhile and suddenly blow blazing hot air; happened whether engine was hot or cold; happened no matter outside air temperature; sometimes cold air would blow for 30-40 minutes, sometimes it would blow cold for just a few minutes before blowing hot.

Current State - had A/C system flushed, coolant & freon added last week; Shop put car on computer and did not find any problems with CCM; in shop A/C performed fine BUT suddenly started blowing hot air even when in shop; Over the weekend - A/C blew cold for 5 minutes, then blazing hot from left front, driver center, passenger center vents; right front vent continued to blow cold air -- this happened on a couple of short drives; This morning - A/C blew cold for 2 minutes, then hot from all 4 front vents.

Shop has recommended these repairs - replace DCCV again; replace hose to DCCV that shows no leak but gets wet; replace coolant expansion tank which is leaking; replace A/C compressor.

** I need advice on what to do here, as I have no confidence that these expensive repairs will fix the problem. **

 

Update from afternoon commute 28-APR
Outside temp = 81 F
Cold air from all 4 dashboard vents for 15 minutes, then hot from Left Side & Driver Center, warm/hot from Passenger Center, cold entire 60 minute trip from Right Dash.

 

Sounds typical of a failing or failed DCCV - those hoses shouldn't be wet or have any indication of moisture on them. I would replace the DCCV.

 

+1
I'm no climate control expert, but if you had cold the entire trip, wouldn't this suggest that the A/C compressor is working properly and the problem is elsewhere in the HVAC system?

Check what these guys have to say...
http://jaguarclimatecontrol.com/diagnose/

 

Thanks for the info. The shop said the A/C Compressor is weak, so I also don't think that's the problem right now. Planning to get the DCCV, hose to DCCV, and leaky Coolant Expansion tank replaced this week or next, and hoping this fixes the problem.

What I'm afraid of is there may be a problem with some of the blenders or flaps that would require removing the dash... I hear that's a VERY expensive job.

 

You can get a hold of a set of AC gauges pretty cheap from Harbor Freight that will tell you what is happening with the compressor.

 

The factory compressors are known to gradually fail (mine did so back in May 2010 after just five years). So you may indeed have a failing DCCV as well as a failing compressor....

 

First a blend door problem is very rare. Leave that alone right now and focus on changing the DCCV, hose and top tank.

Then run the car and report back how it's working.

Does the A/C compressor have any yellow/green staining or liquid on it? There really is no such thing as a weak compressor. It either performs and cools the car or it does not.

If you find staining make plans to replace the compressor. They are cheap and all over the place. Remember the 6 cylinder Lincoln LS also uses the same compressor. ALWAYS change the dryer when replacing the compressor.

Why was the A/C system flushed? We have a split core evaporator and it can't be flushed. Only replaced.

If you had to add Freon you have a leak. Find and fix it.
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