In working on my heating system, the drained coolant was a greenish pink color and the coolant in the expansion tank on top of the motor was a darker all green color. I plan to replace it but what is the proper coolant to use? I have some Prestone Dex-cool and some Beck Arnly that are pink in color. Both are for aluminum engines and is what I use in all my cars, except the Honda which I've never had to mess with.

As usual, all thoughts are appreciated.

 

Which ever type you choose, makes sure it meets the Jag. spec shown in the owners manual.

 

There has been extensive discussion on the proper coolant. You can use the search function to read the threads. I believe Zerex Z05 is an acceptable substitute for the factory coolant.

 

Dexcool meets all required specs for our era of Jaguars. I run it in both of ours with no coolant issues....

 

For this one, don't guess, just know! Check the spec books here:

Jaguar XK8 Spec Books

Spend a few minutes and locate the exact year and engine type on page 44. Depends on the VIN, too. This will tell you the coolant spec. From there, look up the spec in google and then pick a brand that meets the spec. I typically go with Prestone from the parts store, but whatever. Basically, the earlier cars use the "green" coolant, and the later cars use GM "orange" coolant. Mixing coolant type can possibly lead to gelling, plug stuff up and generally ruin your day.

PS: Looking at your sig, you have a model year where the switch occurred. If you see pink and green, there is a possibility someone was confused before, and the coolant types are already mixed. I would definitely find the right type, and do a thorough flush of what is already there. Also, try and remove the upper radiator hose and check for any sign of deposits/scaling/gelling. You mentioned heater issues?

 

Not for the AJ26 Jon.

 

Extensive discussion and then some. On this much I think there is agreement ...

Dexcool and G-05 should never be mixed. If your car is spec'ed for Dexcool, and for some reason you decide to run G-05, you need to purge all the old stuff before putting in the new coolant. (I'm not recommending this, but IF such a change is being made, it's important not to mix.)

 

I think it's preferable not to discuss brand names as some make several different products, not all of which meet the applicable spec.

 

Agreed. As previously recommended, look for the specs printed on the jug before you purchase it....

 

OK, lest there be any confusion ...

The term "Dexcool" started as a brand name but is now used by lots of vendors. Sort of like "Kleenex". It refers to a particular performance spec for what are called OAT coolants. Some of our MYs call for this spec.

The term "G-05" is not so widely used. Just Zerex uses it, I think. It refers to a performance spec for what are called hybrid OAT (HOAT) coolants. Some of our MYs call for this spec.

What these specs mean can be fleshed out at Wikipedia if needed. Some guys here have elected to change from one to the other. Volumes have been written about it. Good idea? That's what the volumes are about.

All I wanted to say here is ...whatever you do, never mix 'em

 

Best pieces of advice above summarized:

1) Flush the system completely before you add new coolant since you are uncertain of what type yours may be (or if it was correct).

2) Read the specs for your particular vehicle and make sure what you buy meets those specs. It is always listed on the label.

 

WHEW! What a can of worms this is. Thanks for all the replies. In the clear light of day the coolant looks dirty yellow. In the header tank it looks green. After I did the work I filtered the old coolant and poured it back in, but it needs to be changed. My vehicle care book says to use spec. ESD-M49B49-A. It seems that this spec is not available and was superseded by spec. WSS-M49B44-D (orange) in 2007. The Prestone meets that spec so I guess it's OK to use. I called a local Jaguar/BMW repair shop and the owner recommended going with the yellow coolant.

I will flush out the old coolant per Jaguar's directions. The local parts store doesn't recycle old coolant so I guess I have to store it indefinitely?

 

John,

That WSS-M49B44-D spec ... Could it be WSS-M97B44-D (Dexcool by another name)? I can't find a reference to the number you posted.

Not to complicate matters but I would not rely on coolant color at all. Different vendors might do different things there.

Never a reason to buy Jag-branded coolant IMO. The prices are insane.

 

+1.

Not relying on colour simplifies things (to me).

 

Mine is a 2001 MY. I have used Prestone DexCool for the nearly 4 years I have owned the car. It happens to be orange.

I have changed it twice. Once when I got the car and again when I changed out the radiator and hoses.

No problems, even in 100F+ summer temps with the A/C going strong.

 

The OEM Jaguar ORANGE coolant LOOKS GREEN in the tank but if you suck some out with a 'turkey baster' type tool you will see that it IS the ORANGE color.

When I worked at the Jaguar dealer I had a customer that accused me of putting GREEN coolant in his 2002 Jaguar and wanted a FLUSH AND CHANGE!!!!!!

He called back later to apologize and said that when he actually removed some from the reservoir it was ORANGE!! It LOOKS GREEN in the reservoir BUT when you take some OUT it IS ORANGE!!!!!!!!!!!!!!!!!!!!!!!

It has a GREEN SHEEN but it is an optical illusion!!!!!!!!!!!!!

bob gauff

 

Now, if things were not already complicated enough ....

 

Jaguar used an orange OAT type coolant. If that is mixed with Ethylene Glycol based coolant it will combine and start turning to a jelled sludge. If that happens you may not see it in the reservoir as it seeks the high point in the system (Intercooler if you have an XKR and top of the radiator in the XK8. If you are not absolutely sure of the coolant history, flush the system and make sure that you get all of it out. Whatever you use, make sure that it meets Jaguar specification and be sure to use distilled water 50/50 mixture. I used a Prestone product (Orange) that meets the Jag specification.

 

In the three years starting with the introduction of the AJ26 in 1998,
Jaguar managed to change coolant spec not once but twice.

it went:

green convential
yellow hoat
red oat

you cannot mix types and the system is hard to flush completely
because some of it embeds in plastic/rubber parts and will leach
out over time.

the yellow hoat (zerex g-05, motorcraft gold) is what i use, even though it came with red (dexcool).

after two cycles, it still likes to pick up a pink tinge.

the reason i avoid dexcool is due to the main differentiating
ingredient being a well known plasticiser. combine that with the earlier
composition head gaskets, and a blown head gasket is not unexpected.

the introduction of the later metal shim head gasket came after
the introduction of dexcool. what were they thinking .. if at all?

 

What should I use? The Jag spec sheet says use: JLM 20404.
The dealer gave me JLM 209723. (Orange)
Others are saying use: Zerex Dex-Cool Antifreeze
I've got a 98 XK8 and per the VIN number, it says coolant spec is: DOW D542.
Any help on this would be greatly appreciated before I incur any more brain damage.
Thanks in advance.