Noisy 4.2

[gaskin662]

Hi,
My brother in law has just purchased a barn find e-type 1966 series 1. All looks good bodywise and a few advisories after pushing it through and MOT.

However the top end is very tappety and noisy. It does sound a bit like a timing chain rattle or noisy tappets. The car only has 30,000 on the speedo but this could be 130,000 we don't really know.

so is this a case of the tappet guides needing staking down or are there other known problems with the top end / timing chains etc...

I presume the engines are pretty robust but do they have problems with small ends / big ends going?

Compression is good and it's running smoothly on all 6 cylinders.

[christopher storey]

The XK engine is phenomenally robust and the bottom end will go on for ever ( as in fact will the whole engine albeit using more and more oil ) . Your noise is extremely unlikely to be small end failure . It is far more likely to be tappet adjustment or timing chain thrash. The tappet clearances and the top chain can be checked in perhaps half an hour, and this is the first thing I would do . At the same time you can look for any sign of the cams hitting the tappet guides, but frankly this is uncommon on the engines of this era, the later engines being more commonly affected . If the engine has stood for many years, then it is possible that the bottom chain tensioner, which depends on oil pressure, is gummed up . This is a more complex problem to solve, but if this were the problem the first thing I would do is to drain the oil, fill the engine with about 6 pints of oil and about the same amount of diesel fuel and run it at say 1500 rpm for quarter of an hour several times, leaving a day between each run . Then drain and refill with 14.5 pints fresh oil and a new filter and see how you get on

[gaskin662]

Helllo Chris,
Thanks for the quick reply and the info. My first thoiughts were timing chain rattle but wasn't sure how robust they are. Plus the engine was running a bit rough on 3 year old petrol so hopefully new petrol will even it up a bit so I can listen a bit better to the noise.

I have ordered some technical manuals so will be able to have a look but good news that it's not the loose cam follower housings I have heard about.

Do the cams suffer from abnormal wear at all? The car will be on it's way to me soon so I can have a proper look so thanks for the initial pointers.

[christopher storey]

Very rare for the cams to wear . However, there are a number of problems which can arise if people who do not know the engine mess about with it. One is that the later engines ( post about 1960 ) had parabolic cams which required .010 and .014 clearances rather than the earlier .004/006 clearance. If someone uses the later clearances on the earlier cams you will get excessive noise

[PeterCrespin]

... there are a number of problems which can arise if people who do not know the engine mess about with it. One is that the later engines ( post about 1960 ) had parabolic cams which required .010 and .014 clearances rather than the earlier .004/006 clearance.

Indeed.

In fact post 68ish have parabolics (identifiable as all 4-bolt cams, or two bolt cams with a clear groove machined in the outer rim of the flange).

The settings are a range 12-14 thou and are the same for inlet and exhaust - not the lower number for inlet and larger for exhaust.

Pete

[tinworm]

Don't forget the quite common wear to the cam bucket guides especially on the exhaust side - with the cam out try rocking them from side to side . There is a maximum amount of play measurable with feeler gauges check the manual for details.

regards Barrie