Hi all.I have a '16 xjl s/c 3.0.my a/c works great when it's cooler outside but once it gets above 75 degrees and above it's barely cool.freon is full,condenser is free of debris,no leaks anywhere.i'm thinking the interior temp sensor or the sensor in the driver side mirror?i did notice the the temp on the dashboard is about a 5-8 degree difference hotter than it actually is outside.thanks for any insight.

 

As always with AC work. Get a set of gauges and then post back what the hi and low side pressures are. Next does the car have any codes? Just changing random parts is not likely to fix it.

Do you have any experience working on AC systems? If not I would take it to a shop. I hate to suggest that with all the problems that come with repair shops.
Unless you have vacuumed down the system and then weighed the amount of Freon that you put back in you have no idea if the the system is "full" or not. How did you determine the Freon was full?
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A system that's only slightly low on Freon can actually get too cold and start freezing up the evaporator coil until the pressure gets so low the low pressure switch is tripped. Are there any codes in SDD? Does your radiator fan kick on immediately when the A/C button is turned on? Did you verify the compressor clutch kicks in and is actually turning? Is your cabin filter present and in good condition ensuring good airflow across the evaporator?

 

thanks for the replies.eurofed(shop that only works on european cars)had the manifold and gauges on it to determine it is full.no codes and the cabin filter is a 2 week old oem filter.i've been working on cars for years but haven't dabbled much with a/c.i'll have to bring it back to them for further diagnosis.clutch does kick on and the fan kicks on after a couple of minutes.

 

If you are located in the Charlotte area I would suggest visiting Performance Rovers as they have the software (SDD) to provide a proper diagnostic test. I've found that all the area Eurofed shops don't have the correct software and aren't familiar with the platform.

 

Full means nothing because that doesn't indicate whether the compressor is behaving correctly. We would need to the know the ambient temp at the time of the test and what the high and low pressures read while the A/C was blowing warm.

 

thanks nvmy...i will take it to them.