What People Say About Engines.....

The more people you talk to about jaguars, the more conflicting opinions you get. These opinions seem to fall into two general catagories:

1. "At that mileage it's just run in" - regardless of mileage
2, "Shhhh, that sounds expensive - I reckon that head/block/diff ets's scrap"

Well I've been taking advice about our oil leak and the funny ticking sound that we get when the engine's cold and on Friday a mate was talking to a Jaguar Specialist in Peterborough:

The oil leak from the head gasket just above the distributor (just like yours) is extremely common on the 4 ltr engine. Apparently there is an O ring in the head gasket that seals around one of the pressurised oil passages. This O ring moves slightly and allows the oil to leak. He has seen many of these at a variety of mileages. His suggestion was to leave it alone unless it is leaking a lot of oil or is too annoying to live with. His reason? He reckoned that replacing the head gasket is not a difficult job, but tends to be one that turns into a much bigger job than planned. Expect several of the exhaust manifold studs to shear off in the head, also do not be too surprised if a head bolt shears off during removal. Once the head is off, having done 170,000 miles expect to be shocked at the state of the valves (burnt) and the amount of wear on the cam shafts. Bingo! Unless you are sufficiently strong willed to put the head back without further attention, a simple head gasket replacement just turned into a top end rebuild! Could you put a worn out head back on?

The ticking noise was a bit of a surprise (well it surprised me). All I told him was it happened when the engine was cold but under a hard load, and it sounded 'tappety'. "That'll be the exhaust", Clive says without a moment's hesitation. "Oh?", says I, "what bit?".
"The manifold. Either it'll be cracked or, more likely, the gasket between it and the head has failed or one of the studs has come loose or sheared off. Take the stainless steel cover off and have a feel around for a blow when the engine is cold. If it's just a loose stud you can sometimes just carefully tighten it up a bit.

The thing is that we can't really have it dropping oil all over the place so I think taking the head off it is inevitable - I really wonder how knackered it can be. The mileage is very high but it has been on the back of an auto box for all that time and by most accounts the AJ6 engine is capable of 250,000 miles before an overhaul.

We may well see....

Simon