Sounds like to be just one one valve, I've checked out things like loose spark plugs and manifold gaskets, all OK.

Thing is, a mechanic friend of mine says that it's a full cam, rods, rockers and tappets job.

It's not a loud noise but I like silky smooth engines (especially V8's).

Is there a method of diagnosing what's at fault and replacing just that or is my friend correct?

Thanks

Daniel said:

Sounds like to be just one one valve, I've checked out things like loose spark plugs and manifold gaskets, all OK.

Thing is, a mechanic friend of mine says that it's a full cam, rods, rockers and tappets job.

It's not a loud noise but I like silky smooth engines (especially V8's).

Is there a method of diagnosing what's at fault and replacing just that or is my friend correct?

Thanks

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I have a similar problem with my diesel,it's making a tapping sound at around 2,500 rpm,I tried an engine flush and oil change which didn't seem to work at first but 200 miles later the problem has become intermittent,today I'll try a hydraulic valve lifter additive and after a few hundred miles I'll follow up with another oil change,if that doesn't work then I'll bite the bullet and recondition the head,I've never been a believer in oil or fuel additives but seemingly they work to a degree.

I did an engine flush and oil change yesterday to no avail

The V8 rocker shafts are well known for wearing on the underside. The Rocher assemblies can be removed and dismantled without removing the heads, just make sure that you are keeping them in the order they come off. Replacement rocker shafts, push rods and rockers are cheap enough to replace when you look at the cost per piece....pity there's 16 of them !!!
The camshaft lobes also tend to wear, as do the tappet faces but you will need the inlet manifold and valley gasket off to see those, again, not too expensive for a camshaft & tappet kit.
If it does turn out to be the camshaft/tappets, it would pay to replace the sprockets and timing chain at the same time.