My newly acquired 2003 XK8 is due for coolant service. According to the service records provided by PO coolant was changed 6 years ago and shop used Jaguar JLM 209722 OEM coolant

Would you do a simple drain and fill or change the thermostat too and do something more comprehensive?

Although an easy DIY project I will have it done at a shop due to coolant disposal and I read where access to the drain plug is a challenge

 

Hi Randy,

Since as far as you know the coolant is 6 years old, its corrosion inhibitors are expired, so it would be prudent to flush the entire system. Be sure the shop uses the correct Organic Acid Technology (OAT) type coolant that meets Ford specification WSS M97B44-D. The most commonly-available coolant that is correct is Prestone Dex-Cool, available at Walmart and all auto parts stores.

Replacing the thermostat is always a good idea if you don't know the history of the old one. Replacing the water pump is also a good idea and Rock Auto carries the same Airtex AW4124 pump that Jaguar supplies as a replacement, except Rock Auto's price is just $36 plus tax and shipping.

Cheers,

Don

 

Two more thoughts:

1. Despite many arguments and reports from members of this forum and others, you do not want a water pump with a metal impeller because OAT coolant does not protect metal impellers from electrolysis or cavitation erosion. That's why manufacturers switched to plastic impellers. The Airtex pump I mentioned in my previous post has a plastic impeller and is the same part Jaguar supplies.

2. Regarding coolant disposal, many auto parts stores will accept it in sealed containers. One of the county recycling centers in our town also accepts used coolant.

Cheers,

Don

 

Mr. Texas Dan did a great write up on coolant flush (pics)

 

Hi Randy,

The DIY by MrTexasDan that Michael posted is excellent, but note that the Zerex G-05 coolant that Dan used in his Jaguar is not appropriate for your 2003 X100 (and probably not for his 2000 either). Earlier X100s were filled with Jaguar D 542 coolant (DOW 542), which was yellow in color. For some reason, many Jaguar owners have been led to believe that Zerex G-05 is equivalent to D542. I have studied the Material Safety Data Sheets of the two coolants and they are not the same.

G-05 is a Hybrid Organic Acid Technology antifreeze, meaning some of its additives contain carbon and some do not. Manufacturers warn against mixing HOAT coolants with either OAT (Organic Acid Technology) or earlier IAT (Inorganic Acid Technology) coolants, and also against mixing OAT and IAT coolants, due to the possibility of adverse reactions such as gel formation, deactivation of corrosion inhibitors, etc.

Using G-05 would probably not be a problem if the system was thoroughly flushed first. However, your 2003 was equipped with orange OAT coolant from the factory, so that's the best choice for your car. You can see Jaguar's specifications in this document:

Jaguar Vehicle Specifications Booklet 1997-2003

For more detailed information on coolant chemistry, see posts #7 - #10 in this thread:

https://www.jaguarforums.com/forum/x...5/#post2069731

Cheers,

Don

 

Thank you Don. I wasn’t planning on using Zerex G 05. I used it in my old Corvettes because the Hoat technology wouldn’t attack the old solder joints in The heater cores. Never had a leak in the heater cores


i plan on using a Dex cool Orange to be compatible with the OEM Jaguar coolant that the dealer used last fill

 

Don,
thanks for this & the linked thread.

I used Dan's procedure when I did my first coolant change eight or nine years ago after the valley hoses. The coolant was yellow (or was it orange?), so could have been either Dow or changed to XLC on one of the motor replacements. Wanted to be sure I didn't mix hence the flush.

"So chaps, from 1999-ish onwards, to avoid confusing the unwashed masses, let's update yesterday's old-fashioned yellow coolant for one that may be recognized by its distinctive orange color"
IIRC the Jaguar XLC stuff looked pink in the bottle

WSS M97B44-D spec coolant can, unsurprisingly, be had from Ford. Just waiting for someone to release a green variant

 

You asked

• Consider both radiator hoses, especially if you see them collapse when the car is cold or if they feel soft.
• Definitely do the thermostat "tower". It is an assembly from Jaguar with pipes, thermostat, new sealed sensor and o-rings. Not terribly expensive ($100?) for all you get, and replaces the aging plastic with new. The older cars have the option of the Aluminum part, but we do not.
• Double/triple check the valley hoses under the intake. Massive pain of a job, but these will let you stranded if they burst. Do a finger test (at least one end is reachable by the thermostat) to see if they are soft and coincide with a nauseated feeling in your stomach. You will know what to do.
• Check the octopus hose. First sign of failure typically involve the end(s) leaking onto the converters and leaving a white residue. Another bear of a job, unfortunately.
• Definitely do a nice chemical cleanup involving heat through the heater code. Amazing difference in cabin heat after that. I can only imagine it helps the rest of the cooling system, too.
• Water pump is cheap ($50?) and easy to reach, so you might want to do it.
• Don't forget to empty/clean/flush the overflow tank in the wheel well.
• FWIW, there is an engine drain plug on the block somewhere. Apparently creates as much of a splashing mess when opened, but must be the lowest point in the system. That plastic plug on the radiator should probably be left alone unless it comes off super easy (plastic plug on the right-hand-side plastic core).

Best of luck, keep us posted.

 

Did a little more checking and Carfax reported cooling system service at 60K in Jan 2016. Called the dealer and it consisted of new thermostat and tower and coolant. Since it is 4 years old I think I'll go another year before coolant change. I'll do the rad hoses at that time as they look to be original.