Any advice? I'm driving from San Diego to Sedona AZ Sunday. That means going through Phoenix. I'm going to get a new battery today because the previous owner I bought it from doesn't know how old the battery is. Any other advice?

 

The only issue I would forsee would be the cooling system, if it hasn't been maintained regularly (the hoses under the SC for example). You could have it tested prior to leaving, just to be safe with that side. I would suggest using an app like Torque and a Bluetooth OBDII adapter to monitor actual temps instead of relying on the gauge, unless you've already had a RealGauge installed to do so, but with only a couple days, that might be hard to arrange. But other than having the cooling system and AC checked, just enjoy the drive.

First summer I had mine, I drove it down through Louisiana in 100+ and had no issues, and would do so again in a heartbeat.

 

As Charles suggests have a good look at the hoses. The rad top hoses, t-stat to block elbow if bulging or dried coolant anywhere then I'd change it.

R's run on the warm side and are fully protected by the knock sensors so use premium gas and it shouldn't be an issue they're built for long runs and the desert tests Jaguar did should stand you in good stead

 

Hi, as long as your cooling system has been looked after well, you should be fine. Did the same with my XJR during summer temperatures in Italy too and had no problems.
If you should experience a minor crack or tiny hole (like from a needle), you can try to fix this temporarily with some gaffa tape and some hose/worm clamps. Helped me once to get my car 800 km home when one of my coolant hoses developed a tiny perforation.
With the tape and several clamps I placed something like a pressure bandage onto the perforation and it worked well for the trip home. Since then I always keep some clamps and tape in the car.

After this, I decided to replace the stock intercooler pump with the uprated Bosch 010 pump, just to be on the safe side ;-)

As long as you're not stuck in traffic you should be fine...have a save trip and enjoy!

 

Make sure your heater works. If your car actually overheats, you'll need to turn the A/C button off, roll down the windows, set the heater on hottest temperature and turn the fan all the way up. I'd also carry a gallon of water or coolant just in case. Anything you gotta do to protect the engine...

 

+1.
You can even set up a high temperature alarm at any setting you want, and it will warn you long before the gauge needle will move up.
I set it at 105C (220F), and I only hit it once, going in slow traffic up a hill in 36C degree high humidity.

You should be fine if your system is in good condition.

 

Floor it the whole way and enjoy the car. Nothing bad will happen if the cooling system is working correctly.

Be prepared for noisy idling, the fan works in 6v normally but can switch to 12v if the engine temp rises - this sounds like a small jet engine is running under the hood.

 

i drive my XJR 2000 in 49 C and it has no issues.

 

Everything went fine. The engine never got hot.

 

Nice !