Jaguar XK Coolant Flush and Fill User Manual

XK Coolant Flush and Fill,

Thermostat Replacement

A Jaguar XK Repair Guide

By MrTexasDan

Jaguar XK Coolant Flush and Fill, Thermostat Replacement

To maintain the long term reliability of the XK cooling system, it must be periodically
flushed, the thermostat must be replaced, and new coolant must be added. This document
gives some information on coolant type and flush interval, and pictorially shows the step by
step coolant flush and thermostat replacement procedure.

The procedure and pictures are from my own 2000 XKR. The procedure for other XKRs is
the same, as far as I know. However, XK8s have a substantially different cooling system due
to the absence of the supercharger intercooler. I have marked steps that should be omitted
when flushing a normally aspirated XK8 engine with a (***).

Corrections or suggestions for improvement are sincerely appreciated.

This document may be freely distributed in its complete and unaltered state, with the author’s
name and email addresses included.

Dan Pechonis
December 26, 2006
Forum name: MrTexasDan
[e-mail]

Revisions:

December 26, 2006 – Version 0.0

 Initial version

January 17, 2006 – Version 1.0

Many thanks go to Dennis07, Gary61, SidVaga, and MarkyM for taking the time to
review this guide and offer their valuable feedback.

 Added text on reason for adding coolant full strength and letting it mix with

the water in the engine.

 Added text on only using chemical flush when changing coolant type or when

clogged cooling system is suspected.

 Added (***) indicator to steps that should be omitted when flushing a

normally aspirated XK8 engine

 Added use of safety glasses and gloves when draining coolant.
 Added labels on a few pictures to clarify orientation of view.
 Added note about keeping an old thermostat as an emergency spare.
 Made some clarifications, fixed a few typos and grammatical errors.

July 9, 2010 – Version 1.1

 Removed references to specific forums.
 Removed some “opinions” on coolant type that have lost some credibility.
 Made a bunch of clarifications.

General Information

I will give my opinions on coolant type and flush interval below. The very last thing I want
to do here is to start another discussion on these points. The readers are encouraged to
research the collective wisdom of the forums and other sources and make their own choices.

Coolant Type

The types and choices are rather confused. Major coolant types include Dexcool products (in
a few colors, but usually associated with orange), G-05 products (usually yellow), and the
green stuff (originally marketed to be environmentally safe, but I wouldn’t take a bath in it).

Check out this paper on antifreeze colors found by Dennis07:

http://filtercouncil.org/techdata/tsbs/05-2.html

Jaguar themselves have switched colors numerous times. It is not apparent which type of
coolant Jaguar colors represent.

In my opinion, there are no fundamental problems with any major type of ethylene glycol
based coolant. However, the coolant Prime Directive is never to mix types. A reaction can
take place that causes the solution to gel and clog heater cores and radiators. After a thorough
chemical flush (like the one outlined in this document), you are free to use Dexcool, G-05, or
even the very-expensive Jag type (whatever it is).

I chose Zerex G-05 (yellow), though recently this type is becoming more difficult to find.

Flush Interval
Flush the cooling system and replace the thermostat every 2 years.

From a post from Bloodworm, “Do NOT wait five years between coolant flush and fills. Even
in a perfect world these NEW coolants just don't make it to five years and it even states it on
the bottle. Five years is the SHELF life, the operating life is more like 2-3 years just like the
green was. Although ALL coolants will still COOL the car for as long as it is a liquid, the
anti-corrosive chemicals break down much sooner than that.”

Use a chemical flush only when changing coolant type, or if cooling system clogging is
suspected.

Parts and Supplies Needed:

 One 25mm to 50mm long M12 diameter Hex Head Bolt and two Hex Nuts (all

should fit a 19mm wrench)

*OR*

One 1” to 2” long ½” diameter Hex Head Bolt and two Hex Nuts (all should fit a
¾” wrench).

 Distilled water, 2 gallons or 8 liters (readily available in the water section of your

local market)

 Coolant , 2 gallons (I use Zerex G-05 yellow)
 Thermostat (for my 2000 XKR - Jaguar #AJ86484, $52.61)
 Shop towels
 Empty gallon containers for pouring water and storing drained coolant.

-optional-

 Chemical flush (I used Zerex Super Flush)
 Intercooler plug sealing washer (Jaguar, #JWV130001, $3.36)
 Coolant pressure cap (Jaguar, #MJA4440BA, $17.67)

Tools Needed:

 Floor jack (preferred), or use Jaguar scissor jack
 Jackstands
 Wheel chocks or wood blocks.
 Fender protectors
 Coolant Drain pan (dish washing pan or similar)
 7mm nut driver or socket
 Large flat head screwdriver
 19mm (or ¾”) box end wrench
 8mm box end wrench
 Torque wrench with 19mm (or ¾”) socket and 8mm socket
 Garden hose (optional)
 Goggles or Safety glasses
 Nitrile, Latex, or Vinyl gloves
 Funnel

Procedure:

General:

 This is a good time to perform a thorough inspection of all coolant hoses,

connections, and seals. This should include the mass of heater hoses behind the
engine by the firewall. Leaks, seeping seals, or cracked, bulged, or weak hoses
should be replaced prior to, or during this procedure.

 Care should always be taken to protect the paint while you lean over the fender.

Wash dirt off of the bodywork *first*, remove belt buckles, and watch for rivets
in jeans or metal zippers, or other potential hazardous bits.

 Take care to dispose of coolant properly. Disposal methods vary widely by

location, so check your local guidelines. I poured the used coolant from the drain
pan into gallon containers as it filled.

 This procedure requires at least 2 engine cool-down periods. Be prepared for each

of these to take 1-2 hours. I did other maintenance items while the engine was
cooling (with the hood open to speed the process).

 For the very first draining, I raised the car and got underneath to locate the drain

plug and remove the alternator air duct. If you already know where the drain is, it
is not at all necessary to raise the car to access it.

 Use a chemical flush only when changing coolant type, or if cooling system clogging

is suspected.

 The (***) indicator is prefixed to steps that should be omitted when flushing a

normally aspirated XK8 engine, instead of the supercharged XKR engine.

 When draining coolant, wear goggles or safety glasses to protect your eyes from

accidental coolant splattering.

 Wear nitrile, latex, or vinyl gloves when handling used coolant to protect skin

against toxins.

*** Step 1) Make a tool to remove and install the intercooler coolant plug, as shown.
Install two hex nuts on an M12 or ½” hex head bolt. Tighten the nuts firmly against each
other. Try to align the flats so that a box end wrench can be used on the inside nut.

Step 2) Park on level ground or better yet, nose down to aid draining. Turn off engine
and allow it to cool. Block the rear wheels with boards or wheel chocks.

Note: If the car is parked even slightly uphill, the coolant will not drain properly. I
found this out the hard way.