[TR] TR4/Webers - that banging noise

[Brian Jones]

John,
That is an interesting conundrum: banging when combusting; not banging when
not combusting. A compression check, as Dave suggests, may give you a clue.
Also check for a cracked exhaust manifold or a loose manifold stud nut.

It could also be a bad valve, seat or piston, and a compression check will
reveal an issue, I'd hope.

Before you take the head off, swap the spark plug with another cylinder and
see if the issue stays at #3.

Let us know how you get on.

Brian

On Sun, Aug 2, 2009 at 4:48 PM, Lee&John Howard <leejohn7 at gmail.com> wrote:

> Well, it doesn't sound good. I discovered that it is cylinder #3 that is
> banging. Removing that spark plug wire removes the sound and reveals an
> engine no noisier than usual.
>
> So what could be banging in there? The lash is fine. I guess I'm going to
> have to remove the head to investigate, aren't I.
>
> Any ideas?
>
> Thanks
>
> John Howard
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