Head Gasket Failure - 4 litre

[PaulE]

The AJ6 engine is usually described in print as 'bulletproof - the best 6 cyl engine Jaguar ever made', but then also rather as an aside 'can be prone to cylinder head gasket failure'. Mine went 3 years ago, and I have just heard today that a friends went on a similar 4 litre car this weekend.

What's going on? Does anybody know what this obvious defect is down to and if it can be avoided? It is no minor annoyance as the repair takes quite a long time by the time the head has been skimmed and rebuilt and new head studs, gasket set etc been obtained, and the cost will be the thick end of £1000.

I have been reading up about 'Cometic MLS' stainless steel multi layer gaskets which look like a step forward. Has anybody any practical experience of them and know whether more reliability could be obtained by their use. The UK agent is Piper Cams.

[steveww]

On my Lotus/Ford Twinc the laminated head gasket blew a couple of times so I replaced it with a composite one which is still going strong. Not sure if they do one for the Jag though.

Of course what works for the Lotus twinc may not work for the Jag. However they are a good quality product.

[PaulE]

Received this email from David Marks which may be of interest to fellow sufferers - perhaps things are not as black as they first appear.


All engines have weak points and compared to the older XK unit which it succeeded, the AJ6 is bullet proof.

the youngest of these engines is now 16 years old so head gasket failure is not to be unexpected perhaps but is still rare after all these years.

it is not an obvious defect, just one of those things, most XK units, for example, have had to be fully rebuilt by now, at least once.

Servicing standards and whether the car has been stood for a long time etc or just done short journeys can also be a factor in the longevity of the gasket.

We have never had to replace a gasket on an engine previously repaired and we still know a few such cars some years after the job was done.

I don't know anything about the cometic gasket, we still use the Jaguar OE kit when doing one.

Regards

David Marks

[Brakebuster]

i think the main point here is that peeps tend to forget that their pride and joy is getting OLD

mechanical things fail , even ones made by Jaguar

if you want warranted , no hassle driving that will never break down

then i'm afraid you have to buy a brand new car every year, and even then its not that simple

please remember, i'm not having a ' go ' just living in the real world ,

i own a £55,000 Sovereign XJ , well, thats how much it cost new, but i realise that now its 11 years old, its the same car, but no where near as valuable , and only worth £3k at most at the present , and trust me , its in great condition

if you look at the new gasket verses the old one, ask yourself, how long did the ' old ' version last, and you will surprise yourself by the answer, just because it has broken well after 16 years doesn't mean its a design fault, and should be replaced with ' modern ' ones, that as of yet , haven't been installed for anywhere as long as the original were ,

same goes for all these ' polly ' suspension bushes ,

sorry , rant over,

good luck with the engine rebuild ,

BB