2008 Jaguar XKR.

This has been happening for so some time. AC blows cold when driving at a good speed. Starts blowing hot air when stopped at an intersection or idling. If I give gas in neutral, it gets cold. I am a novice on this and would like any guidance, before I go the auto shop, so that they won't charge me too much.
Freon is full and had it checked. Thanks

 

Make sure your cooling fans are operating properly. Other than getting results by revving in Neutral, it sounds like your cooling fans are not running. How's radiator temp?

 

Wrong car posting

 

Must be summer. Read the codes for the HVAC and see if it says the pressure is low.

 

If a shop tells you it the AC compressor get a 1st ,2nd & 3rd opinion. Seems like every shop has a different price quote for these cars when it comes to AC

 

Sorry. Was not watching the location of posting. How do I move it to right sub forum.

 

If it's the 08 XKR you're referring to, you're in the right forum. It was probably already moved.

 

It is 2008 XKR. Thanks

 

My first guess is that it is low on freon. How did they check it? I would assume/hope that BOTH the suction and discharge pressures were measured to determine that the charge is correct. Knowing the two pressures, and ambient temperature when the pressures were taken, would be a big help in troubleshooting this.

Is it blowing truly HOT air, like from the heater, or just ambient/warm temperature air?

It could be a radiator fan, but I would expect you to have engine overheating problems before A/C problems if it is a radiator fan. I would start by confirming that the fan is running and then check the coolant temperature with an OBD reader to confirm that the coolant is not running hot.

Any belts squeaking/loose? Slipping will not allow the compressor to turn as fast as it should, especially at low speed.

 

Is there an "easy" way to get HVAC codes? Or is one of the more sophisticated readers such as SDD or Foxwell needed?

 

Mine came up on the LR2 so I don't think it's too difficult to find if the reader finds the HVAC controller.

To the OP, higher revs and airflow across the radiators helps the system process refrigerant easier so it cools better.

 

 

Yep, if you think about how a refrigerant system works you'll understand it better. Basically the pump compresses warm refrigerant gasses into hot liquid which gets 'cooled' via the condenser out by the radiator and then goes through a tiny orifice which allows it to turn back into a ice cold gas. The pressure change through the orifice is where the cooling effect comes into play. The cold gas goes through the HVAC system evaporator heat transfer and back to the compressor warm gas.

The pressure switch is on the suction side of the pump and sees system pressure but once the pump starts compressing the gas into fluid the suction side pressure can drop below the switch threshold which will cause the pump to shut off.

If there isn't enough fluid in the system the dwell time in the condenser the temps get out of whack and the system performance suffers which is what's happening at low speed / RPM.

 

i have the same issue with my 2011 XKR, and ran across this TBS:
https://jlr.oemdtc.com/69/inadequate...10-2016-jaguar

there is affected vin range and my car is in that range....

anyone has this fixed yet?

 

Hello Everyone. Thanks a lot for all the wonderful advise and suggestions and most of you are on the dot with the analysis.

Here is what happened. I had the Spacer and O ring put in, as I was getting a Whistling noise at low speeds, which was so annoying specially in Phoenix summers, when I have to use AC for sure. The mechanic did a fantastic job of following the TSB and fixing the nagging whistling problem, but for some reason, did not charge the freon fully.

I went back and had him look at it one more time and he apologized and took care of freon and made sure the repairs performed were not leaking any freon.

Have been running the car for 2 days now and AC is working great and the Whistling noise is gone.

Again thanks to you all for the wonderful help. This is a great site.

 

I have the whistling issue. going to do this next week. glad you figured it out.

 

I am having intermittent hot air again. Having the mechanic check the belts and slippage. May be belts are original as car has 67k Miles. May be time to change belts. AC when it works blows pretty cold. That means compressor is ok.

 

I will tomorrow update you on the TSB and part #'s. You need a spacer that is available only at Jag dealer. Its less than $ 15. However the O ring at Jag Dealer is $ 26 (Robbery at gun point). My mechanic used a generic O ring that you can buy a bunch for a few bucks.

 

Here are the parts you need to fix the whistling noise.

1. Spacer ring: Jag Part # C2P22168 (This you have to get it from Jag)
2. O Ring: Jag Part # 02C2C7668 (You can use after market for real cheap, but Jag part is $ 26.

Technical bulletin: JTB00207 August 31, 2010
Air conditioning Whistle Noise.

Hope this helps

 

2008 Jaguar XKR

The mechanic ruled out the following....

Freon is full not losing,
Compressor is working ok.
Belts in good condition.
Cooling fan is kicking in..

Next he is going to look at electrical issue of sensors.

Any one has any ideas.