[xj40] blown head gasket repair advice

My 1990 XJ6 Sovreign has all the signs of a blown head gasket.
Losing fluid, oil in the coolant, milky oil cap. Steam in the
exhaust. My initial checking puts repair by a shop that’ll do it
at &1300=$1700. I’m not a stranger to auto repair, but I’ve never
tried to replace a head gasket. I need advice.–
coveralls
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In reply to a message from coveralls sent Tue 2 Jan 2007:

Many forum members have done this job - search the ‘Modern’
and ‘XJ40’ forums under ‘new head gasket’ or similar
terminology to read up on others experience.

I did mine some years ago and it’s not rocket science!

First, get a Haynes Manual. The procedures in there are
pretty good - the only major difference in my case is that I
did not totally remove the inlet manifold from the car -
just unbolted it and lay it on the left inner wing after
removing the air filter box and MAF and displacing the
coolant reservoir.

Dave and Pat Lokensgard did a picture sequence of the job on
their car :-

http://www.jag-lovers.org/snaps/snap_view.php3?id=950770462

You will need a camshaft setting tool to get the valve
timing correct, but you can easily make one that I designed
instead of the factory special tool:-

http://www.jag-lovers.org/snaps/snap_view.php3?id=1086870471

You will need a deep OHC valve spring compressor too.

There are other sources of information � one I like in
particular is an article in the October 2001 edition of
Jaguar Monthly � the UK magazine but I don�t think you can
order back issues of that edition. However, they did another
article in the April and May 2005 editions of Jaguar World
Monthly for which you should be able to get back issues:-

http://www.jaguar-world.com/cgi-bin/purchase.cgi?y=2005&i=050004JWM&s=bi

http://www.jaguar-world.com/cgi-bin/purchase.cgi?y=2005&i=050005JWM&s=bi

Both of these have dozens of colour illustrations and step
by step instructions for doing the job.

Some other advice off the top of my head -

  • Make sure you get a genuine OEM Jaguar gasket set - it
    contains everything you need to do the job including a full
    set of 24 valve stem seals so you can fit seals to the
    exhaust side for the first time

  • You do NOT need to replace all of the 14 head bolts
    particularly if you believe that this is the first time the
    head has been removed.- but pay strict attention to the
    method of tightening them on re-fitment.

  • Take your time - allow a full week of evenings and
    weekends to do the gasket and a complete valve job to clean
    them up and lap the seats.

  • Before you unbolt the head, measure and note the exact
    valve clearances so that you know if you need to fit
    different shims on re-build and keep all
    valve/spring/collet/cap/cam follower bucket and shim set
    together, clearly identified to their original location in
    the head so they are re-fitted from whence they came.

  • Be prepared to find corrosion / erosion damage around the
    coolant passages in the head which you may have to get
    filled with JB weld (or aluminum weld if bad) and machine
    skimmed to resurface the head. Also be prepared to find
    warping in the two exhaust manifolds which you may also need
    to get machined flat.

Apart from that - enjoy! :-)–
The original message included these comments:

Losing fluid, oil in the coolant, milky oil cap. Steam in the
exhaust. My initial checking puts repair by a shop that’ll do it
at &1300=$1700. I’m not a stranger to auto repair, but I’ve never
tried to replace a head gasket. I need advice.


Bryan N, '91 Sovereign 4.0 L, (RHD)
Cambridge, United Kingdom
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In reply to a message from coveralls sent Tue 2 Jan 2007:

Hi Coveralls,

    I've done many head gaskets (too many to admit), but never 

on this car. Search the forum, I’ve found some good links with
photos here and there. The problem with this car (please correct
me, other experts) is that you get aluminum in the antifreeze, and
it eats away at the water jackets after a while-> aluminum oxide =
the stuff sand paper’s made of. If it’s too far gone, you’ll need
to have the head welded. I did this job on a Toyota pickup a long
time ago we had an aircraft welder in a shop on Long Island, NY
(lived there a while back). He filled in the water jackets with
aluminum, then the machine shop milled them out to the correct
size). Back then it was not so expensive, a few hundred USD.
You’ll need very good torque wrench, and some patience. The
exhaust pipes tend to be a bit of a chore to remove, if its not
been off before.
I’m nearly in the same boat (90 sov, 140K miles):
milky under the oil filler cap, burning steam (although so far, not
extremely badly), oil leaking from around the distributor cap,
smell antifreeze, losing antifreeze…
Please keep me posted on how you make out! I hope
mine holds out at least until April (warmer weather).

Regards,
Mike L.–
The original message included these comments:

Losing fluid, oil in the coolant, milky oil cap. Steam in the
exhaust. My initial checking puts repair by a shop that’ll do it
at &1300=$1700. I’m not a stranger to auto repair, but I’ve never


Mike London
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