Wondering if it’s ok to mix coolant types for my 1998 XJ8. My mechanic currently uses the attached green fluid. Thanks!

 

DO NOT MIX.
You can use almost any coolant as long as you flush out old and fill with whatever you want.

Some coolants turn to brown sludge when mixed together.

 

Hello..... Do NOT use green coolant.... ONLY orange DEX-COOL.

 

Don't go by the colour but by what type of coolant you currently have in the engine, the ethylene glycol or the OAT type. The two must not be mixed.

Ethylene glycol type coolant can come in various colours: I have seen green, blue and red which can all be mixed. The coolant type should be written on the bottle.

 

The 1998 X308 and X100 came from the factory with YELLOW D542.

The Extended Life Coolant (XLC) (orange) was introduced later.

 

I can see that the Workshop Manual specifies antifreeze ESD-M97B49-A (Ford spec) which is the ethylene glycol type. If one has not switched to the later OAT type introduced by Jaguar, either stick to ethylene glycol (like, for example, the blue bottle Napa "Extended Life" coolant) or do a complete flush and go for the later OAT coolant. Mixing the two results in:




and can also clog the radiator badly.

 

Little twist. If your fluid is green, it doesn't mean you have green fluid. I've put the flourescent green dye in my 911 (pink fluid) and my Jag (orange fluid) to find water leaks and check for contamination in oil. Even without a UV light looks green. To flush, buy 8 gallons of distilled water. Open petcock drain on bottom of radiator. The coolant system holds about 11 quarts and I think about half will drain out of petcock. Fill with distilled. Warm up engine with heater on. Rinse and repeat. By my rough math, if you started with a 50/50 coolant/water mixture after 5 cycles you'll be at 1.5% original coolant.

 

I use this. before I used FORD OEM orange coolant

 

I have always used the orange stuff with great results.
Mixing anti-freeze types is asking for trouble.

 

Prestone Orange