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best coolant

Dave Maupin
Carolina Jaguar Club *

forum user since 2005-04-12


I've got a Series II pre-HE V12. I'm in the process of replacing the coolant hoses so will need to replace the coolant as well. I'd like to know what members think is the preferred coolant for an engine with an aluminum block and heads.

Dave Maupin
Taylorsville, NC
1976 XJ 5.3C

Re.: best coolant

William Brady
Jaguar Owners Club, Inc. *

forum user since 2004-02-15


Edited on 2012-05-10 23:43:50

Thats a lot of hoses, I would change/test the thermostats at the same time To answer your question, It depends on your climate, if you face freezing temps then you need to use antifreeze and I don't think the brand matters. If you don't/or you change your coolant to suit the seasons then you only need distilled/bottled water with a lubrication additive like soluble oil or bars leak etc.ps I have just been working on a one owner 77 with 60,000 miles!

Jaguar affectionado and etc.

Re.: best coolant

Michael Frank
The Jaguar Club of Ohio *

forum user since 2002-11-02


No, it doesn't depend on climate. Antifreeze is needed in all climates, and the mix should be 50/50. Water has better transfer characteristics, but glycol has much lower surface tension and higher boiling point. It works to prevent cavitation damage. If you've ever discovered "corrosion" in your water pump involute or thermostat housing, the most likely cause isn't rust, it's cavitation damage due to running a weak coolant mix.

In answer to your question, old fashioned silicate rust inhibitors have a very high affinity to aluminum. Unfortunately, silicates are being replaced with "long life" OAT inhibitors. Aside from the fact that they are very slow-acting, OATs can actually cause old silicate deposits to be come mobile in an old block. A good choice is "Xerex Original Formula", which is a traditional, low-silicate antifreeze. There are three versions of Xerex, you're going to have to hunt for "original formula".